treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / drivers / i2c / busses / i2c-omap.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * TI OMAP I2C master mode driver
4  *
5  * Copyright (C) 2003 MontaVista Software, Inc.
6  * Copyright (C) 2005 Nokia Corporation
7  * Copyright (C) 2004 - 2007 Texas Instruments.
8  *
9  * Originally written by MontaVista Software, Inc.
10  * Additional contributions by:
11  *      Tony Lindgren <tony@atomide.com>
12  *      Imre Deak <imre.deak@nokia.com>
13  *      Juha Yrjölä <juha.yrjola@solidboot.com>
14  *      Syed Khasim <x0khasim@ti.com>
15  *      Nishant Menon <nm@ti.com>
16  */
17
18 #include <linux/module.h>
19 #include <linux/delay.h>
20 #include <linux/i2c.h>
21 #include <linux/err.h>
22 #include <linux/interrupt.h>
23 #include <linux/completion.h>
24 #include <linux/platform_device.h>
25 #include <linux/clk.h>
26 #include <linux/io.h>
27 #include <linux/of.h>
28 #include <linux/of_device.h>
29 #include <linux/slab.h>
30 #include <linux/platform_data/i2c-omap.h>
31 #include <linux/pm_runtime.h>
32 #include <linux/pinctrl/consumer.h>
33
34 /* I2C controller revisions */
35 #define OMAP_I2C_OMAP1_REV_2            0x20
36
37 /* I2C controller revisions present on specific hardware */
38 #define OMAP_I2C_REV_ON_2430            0x00000036
39 #define OMAP_I2C_REV_ON_3430_3530       0x0000003C
40 #define OMAP_I2C_REV_ON_3630            0x00000040
41 #define OMAP_I2C_REV_ON_4430_PLUS       0x50400002
42
43 /* timeout waiting for the controller to respond */
44 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
45
46 /* timeout for pm runtime autosuspend */
47 #define OMAP_I2C_PM_TIMEOUT             1000    /* ms */
48
49 /* timeout for making decision on bus free status */
50 #define OMAP_I2C_BUS_FREE_TIMEOUT (msecs_to_jiffies(10))
51
52 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
53 enum {
54         OMAP_I2C_REV_REG = 0,
55         OMAP_I2C_IE_REG,
56         OMAP_I2C_STAT_REG,
57         OMAP_I2C_IV_REG,
58         OMAP_I2C_WE_REG,
59         OMAP_I2C_SYSS_REG,
60         OMAP_I2C_BUF_REG,
61         OMAP_I2C_CNT_REG,
62         OMAP_I2C_DATA_REG,
63         OMAP_I2C_SYSC_REG,
64         OMAP_I2C_CON_REG,
65         OMAP_I2C_OA_REG,
66         OMAP_I2C_SA_REG,
67         OMAP_I2C_PSC_REG,
68         OMAP_I2C_SCLL_REG,
69         OMAP_I2C_SCLH_REG,
70         OMAP_I2C_SYSTEST_REG,
71         OMAP_I2C_BUFSTAT_REG,
72         /* only on OMAP4430 */
73         OMAP_I2C_IP_V2_REVNB_LO,
74         OMAP_I2C_IP_V2_REVNB_HI,
75         OMAP_I2C_IP_V2_IRQSTATUS_RAW,
76         OMAP_I2C_IP_V2_IRQENABLE_SET,
77         OMAP_I2C_IP_V2_IRQENABLE_CLR,
78 };
79
80 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
81 #define OMAP_I2C_IE_XDR         (1 << 14)       /* TX Buffer drain int enable */
82 #define OMAP_I2C_IE_RDR         (1 << 13)       /* RX Buffer drain int enable */
83 #define OMAP_I2C_IE_XRDY        (1 << 4)        /* TX data ready int enable */
84 #define OMAP_I2C_IE_RRDY        (1 << 3)        /* RX data ready int enable */
85 #define OMAP_I2C_IE_ARDY        (1 << 2)        /* Access ready int enable */
86 #define OMAP_I2C_IE_NACK        (1 << 1)        /* No ack interrupt enable */
87 #define OMAP_I2C_IE_AL          (1 << 0)        /* Arbitration lost int ena */
88
89 /* I2C Status Register (OMAP_I2C_STAT): */
90 #define OMAP_I2C_STAT_XDR       (1 << 14)       /* TX Buffer draining */
91 #define OMAP_I2C_STAT_RDR       (1 << 13)       /* RX Buffer draining */
92 #define OMAP_I2C_STAT_BB        (1 << 12)       /* Bus busy */
93 #define OMAP_I2C_STAT_ROVR      (1 << 11)       /* Receive overrun */
94 #define OMAP_I2C_STAT_XUDF      (1 << 10)       /* Transmit underflow */
95 #define OMAP_I2C_STAT_AAS       (1 << 9)        /* Address as slave */
96 #define OMAP_I2C_STAT_BF        (1 << 8)        /* Bus Free */
97 #define OMAP_I2C_STAT_XRDY      (1 << 4)        /* Transmit data ready */
98 #define OMAP_I2C_STAT_RRDY      (1 << 3)        /* Receive data ready */
99 #define OMAP_I2C_STAT_ARDY      (1 << 2)        /* Register access ready */
100 #define OMAP_I2C_STAT_NACK      (1 << 1)        /* No ack interrupt enable */
101 #define OMAP_I2C_STAT_AL        (1 << 0)        /* Arbitration lost int ena */
102
103 /* I2C WE wakeup enable register */
104 #define OMAP_I2C_WE_XDR_WE      (1 << 14)       /* TX drain wakup */
105 #define OMAP_I2C_WE_RDR_WE      (1 << 13)       /* RX drain wakeup */
106 #define OMAP_I2C_WE_AAS_WE      (1 << 9)        /* Address as slave wakeup*/
107 #define OMAP_I2C_WE_BF_WE       (1 << 8)        /* Bus free wakeup */
108 #define OMAP_I2C_WE_STC_WE      (1 << 6)        /* Start condition wakeup */
109 #define OMAP_I2C_WE_GC_WE       (1 << 5)        /* General call wakeup */
110 #define OMAP_I2C_WE_DRDY_WE     (1 << 3)        /* TX/RX data ready wakeup */
111 #define OMAP_I2C_WE_ARDY_WE     (1 << 2)        /* Reg access ready wakeup */
112 #define OMAP_I2C_WE_NACK_WE     (1 << 1)        /* No acknowledgment wakeup */
113 #define OMAP_I2C_WE_AL_WE       (1 << 0)        /* Arbitration lost wakeup */
114
115 #define OMAP_I2C_WE_ALL         (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
116                                 OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
117                                 OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
118                                 OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
119                                 OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
120
121 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
122 #define OMAP_I2C_BUF_RDMA_EN    (1 << 15)       /* RX DMA channel enable */
123 #define OMAP_I2C_BUF_RXFIF_CLR  (1 << 14)       /* RX FIFO Clear */
124 #define OMAP_I2C_BUF_XDMA_EN    (1 << 7)        /* TX DMA channel enable */
125 #define OMAP_I2C_BUF_TXFIF_CLR  (1 << 6)        /* TX FIFO Clear */
126
127 /* I2C Configuration Register (OMAP_I2C_CON): */
128 #define OMAP_I2C_CON_EN         (1 << 15)       /* I2C module enable */
129 #define OMAP_I2C_CON_BE         (1 << 14)       /* Big endian mode */
130 #define OMAP_I2C_CON_OPMODE_HS  (1 << 12)       /* High Speed support */
131 #define OMAP_I2C_CON_STB        (1 << 11)       /* Start byte mode (master) */
132 #define OMAP_I2C_CON_MST        (1 << 10)       /* Master/slave mode */
133 #define OMAP_I2C_CON_TRX        (1 << 9)        /* TX/RX mode (master only) */
134 #define OMAP_I2C_CON_XA         (1 << 8)        /* Expand address */
135 #define OMAP_I2C_CON_RM         (1 << 2)        /* Repeat mode (master only) */
136 #define OMAP_I2C_CON_STP        (1 << 1)        /* Stop cond (master only) */
137 #define OMAP_I2C_CON_STT        (1 << 0)        /* Start condition (master) */
138
139 /* I2C SCL time value when Master */
140 #define OMAP_I2C_SCLL_HSSCLL    8
141 #define OMAP_I2C_SCLH_HSSCLH    8
142
143 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
144 #define OMAP_I2C_SYSTEST_ST_EN          (1 << 15)       /* System test enable */
145 #define OMAP_I2C_SYSTEST_FREE           (1 << 14)       /* Free running mode */
146 #define OMAP_I2C_SYSTEST_TMODE_MASK     (3 << 12)       /* Test mode select */
147 #define OMAP_I2C_SYSTEST_TMODE_SHIFT    (12)            /* Test mode select */
148 /* Functional mode */
149 #define OMAP_I2C_SYSTEST_SCL_I_FUNC     (1 << 8)        /* SCL line input value */
150 #define OMAP_I2C_SYSTEST_SCL_O_FUNC     (1 << 7)        /* SCL line output value */
151 #define OMAP_I2C_SYSTEST_SDA_I_FUNC     (1 << 6)        /* SDA line input value */
152 #define OMAP_I2C_SYSTEST_SDA_O_FUNC     (1 << 5)        /* SDA line output value */
153 /* SDA/SCL IO mode */
154 #define OMAP_I2C_SYSTEST_SCL_I          (1 << 3)        /* SCL line sense in */
155 #define OMAP_I2C_SYSTEST_SCL_O          (1 << 2)        /* SCL line drive out */
156 #define OMAP_I2C_SYSTEST_SDA_I          (1 << 1)        /* SDA line sense in */
157 #define OMAP_I2C_SYSTEST_SDA_O          (1 << 0)        /* SDA line drive out */
158
159 /* OCP_SYSSTATUS bit definitions */
160 #define SYSS_RESETDONE_MASK             (1 << 0)
161
162 /* OCP_SYSCONFIG bit definitions */
163 #define SYSC_CLOCKACTIVITY_MASK         (0x3 << 8)
164 #define SYSC_SIDLEMODE_MASK             (0x3 << 3)
165 #define SYSC_ENAWAKEUP_MASK             (1 << 2)
166 #define SYSC_SOFTRESET_MASK             (1 << 1)
167 #define SYSC_AUTOIDLE_MASK              (1 << 0)
168
169 #define SYSC_IDLEMODE_SMART             0x2
170 #define SYSC_CLOCKACTIVITY_FCLK         0x2
171
172 /* Errata definitions */
173 #define I2C_OMAP_ERRATA_I207            (1 << 0)
174 #define I2C_OMAP_ERRATA_I462            (1 << 1)
175
176 #define OMAP_I2C_IP_V2_INTERRUPTS_MASK  0x6FFF
177
178 struct omap_i2c_dev {
179         struct device           *dev;
180         void __iomem            *base;          /* virtual */
181         int                     irq;
182         int                     reg_shift;      /* bit shift for I2C register addresses */
183         struct completion       cmd_complete;
184         struct resource         *ioarea;
185         u32                     latency;        /* maximum mpu wkup latency */
186         void                    (*set_mpu_wkup_lat)(struct device *dev,
187                                                     long latency);
188         u32                     speed;          /* Speed of bus in kHz */
189         u32                     flags;
190         u16                     scheme;
191         u16                     cmd_err;
192         u8                      *buf;
193         u8                      *regs;
194         size_t                  buf_len;
195         struct i2c_adapter      adapter;
196         u8                      threshold;
197         u8                      fifo_size;      /* use as flag and value
198                                                  * fifo_size==0 implies no fifo
199                                                  * if set, should be trsh+1
200                                                  */
201         u32                     rev;
202         unsigned                b_hw:1;         /* bad h/w fixes */
203         unsigned                bb_valid:1;     /* true when BB-bit reflects
204                                                  * the I2C bus state
205                                                  */
206         unsigned                receiver:1;     /* true when we're in receiver mode */
207         u16                     iestate;        /* Saved interrupt register */
208         u16                     pscstate;
209         u16                     scllstate;
210         u16                     sclhstate;
211         u16                     syscstate;
212         u16                     westate;
213         u16                     errata;
214 };
215
216 static const u8 reg_map_ip_v1[] = {
217         [OMAP_I2C_REV_REG] = 0x00,
218         [OMAP_I2C_IE_REG] = 0x01,
219         [OMAP_I2C_STAT_REG] = 0x02,
220         [OMAP_I2C_IV_REG] = 0x03,
221         [OMAP_I2C_WE_REG] = 0x03,
222         [OMAP_I2C_SYSS_REG] = 0x04,
223         [OMAP_I2C_BUF_REG] = 0x05,
224         [OMAP_I2C_CNT_REG] = 0x06,
225         [OMAP_I2C_DATA_REG] = 0x07,
226         [OMAP_I2C_SYSC_REG] = 0x08,
227         [OMAP_I2C_CON_REG] = 0x09,
228         [OMAP_I2C_OA_REG] = 0x0a,
229         [OMAP_I2C_SA_REG] = 0x0b,
230         [OMAP_I2C_PSC_REG] = 0x0c,
231         [OMAP_I2C_SCLL_REG] = 0x0d,
232         [OMAP_I2C_SCLH_REG] = 0x0e,
233         [OMAP_I2C_SYSTEST_REG] = 0x0f,
234         [OMAP_I2C_BUFSTAT_REG] = 0x10,
235 };
236
237 static const u8 reg_map_ip_v2[] = {
238         [OMAP_I2C_REV_REG] = 0x04,
239         [OMAP_I2C_IE_REG] = 0x2c,
240         [OMAP_I2C_STAT_REG] = 0x28,
241         [OMAP_I2C_IV_REG] = 0x34,
242         [OMAP_I2C_WE_REG] = 0x34,
243         [OMAP_I2C_SYSS_REG] = 0x90,
244         [OMAP_I2C_BUF_REG] = 0x94,
245         [OMAP_I2C_CNT_REG] = 0x98,
246         [OMAP_I2C_DATA_REG] = 0x9c,
247         [OMAP_I2C_SYSC_REG] = 0x10,
248         [OMAP_I2C_CON_REG] = 0xa4,
249         [OMAP_I2C_OA_REG] = 0xa8,
250         [OMAP_I2C_SA_REG] = 0xac,
251         [OMAP_I2C_PSC_REG] = 0xb0,
252         [OMAP_I2C_SCLL_REG] = 0xb4,
253         [OMAP_I2C_SCLH_REG] = 0xb8,
254         [OMAP_I2C_SYSTEST_REG] = 0xbC,
255         [OMAP_I2C_BUFSTAT_REG] = 0xc0,
256         [OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
257         [OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
258         [OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
259         [OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
260         [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
261 };
262
263 static int omap_i2c_xfer_data(struct omap_i2c_dev *omap);
264
265 static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap,
266                                       int reg, u16 val)
267 {
268         writew_relaxed(val, omap->base +
269                         (omap->regs[reg] << omap->reg_shift));
270 }
271
272 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *omap, int reg)
273 {
274         return readw_relaxed(omap->base +
275                                 (omap->regs[reg] << omap->reg_shift));
276 }
277
278 static void __omap_i2c_init(struct omap_i2c_dev *omap)
279 {
280
281         omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
282
283         /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
284         omap_i2c_write_reg(omap, OMAP_I2C_PSC_REG, omap->pscstate);
285
286         /* SCL low and high time values */
287         omap_i2c_write_reg(omap, OMAP_I2C_SCLL_REG, omap->scllstate);
288         omap_i2c_write_reg(omap, OMAP_I2C_SCLH_REG, omap->sclhstate);
289         if (omap->rev >= OMAP_I2C_REV_ON_3430_3530)
290                 omap_i2c_write_reg(omap, OMAP_I2C_WE_REG, omap->westate);
291
292         /* Take the I2C module out of reset: */
293         omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
294
295         /*
296          * NOTE: right after setting CON_EN, STAT_BB could be 0 while the
297          * bus is busy. It will be changed to 1 on the next IP FCLK clock.
298          * udelay(1) will be enough to fix that.
299          */
300
301         /*
302          * Don't write to this register if the IE state is 0 as it can
303          * cause deadlock.
304          */
305         if (omap->iestate)
306                 omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, omap->iestate);
307 }
308
309 static int omap_i2c_reset(struct omap_i2c_dev *omap)
310 {
311         unsigned long timeout;
312         u16 sysc;
313
314         if (omap->rev >= OMAP_I2C_OMAP1_REV_2) {
315                 sysc = omap_i2c_read_reg(omap, OMAP_I2C_SYSC_REG);
316
317                 /* Disable I2C controller before soft reset */
318                 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG,
319                         omap_i2c_read_reg(omap, OMAP_I2C_CON_REG) &
320                                 ~(OMAP_I2C_CON_EN));
321
322                 omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
323                 /* For some reason we need to set the EN bit before the
324                  * reset done bit gets set. */
325                 timeout = jiffies + OMAP_I2C_TIMEOUT;
326                 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
327                 while (!(omap_i2c_read_reg(omap, OMAP_I2C_SYSS_REG) &
328                          SYSS_RESETDONE_MASK)) {
329                         if (time_after(jiffies, timeout)) {
330                                 dev_warn(omap->dev, "timeout waiting "
331                                                 "for controller reset\n");
332                                 return -ETIMEDOUT;
333                         }
334                         msleep(1);
335                 }
336
337                 /* SYSC register is cleared by the reset; rewrite it */
338                 omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, sysc);
339
340                 if (omap->rev > OMAP_I2C_REV_ON_3430_3530) {
341                         /* Schedule I2C-bus monitoring on the next transfer */
342                         omap->bb_valid = 0;
343                 }
344         }
345
346         return 0;
347 }
348
349 static int omap_i2c_init(struct omap_i2c_dev *omap)
350 {
351         u16 psc = 0, scll = 0, sclh = 0;
352         u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
353         unsigned long fclk_rate = 12000000;
354         unsigned long internal_clk = 0;
355         struct clk *fclk;
356         int error;
357
358         if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) {
359                 /*
360                  * Enabling all wakup sources to stop I2C freezing on
361                  * WFI instruction.
362                  * REVISIT: Some wkup sources might not be needed.
363                  */
364                 omap->westate = OMAP_I2C_WE_ALL;
365         }
366
367         if (omap->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
368                 /*
369                  * The I2C functional clock is the armxor_ck, so there's
370                  * no need to get "armxor_ck" separately.  Now, if OMAP2420
371                  * always returns 12MHz for the functional clock, we can
372                  * do this bit unconditionally.
373                  */
374                 fclk = clk_get(omap->dev, "fck");
375                 if (IS_ERR(fclk)) {
376                         error = PTR_ERR(fclk);
377                         dev_err(omap->dev, "could not get fck: %i\n", error);
378
379                         return error;
380                 }
381
382                 fclk_rate = clk_get_rate(fclk);
383                 clk_put(fclk);
384
385                 /* TRM for 5912 says the I2C clock must be prescaled to be
386                  * between 7 - 12 MHz. The XOR input clock is typically
387                  * 12, 13 or 19.2 MHz. So we should have code that produces:
388                  *
389                  * XOR MHz      Divider         Prescaler
390                  * 12           1               0
391                  * 13           2               1
392                  * 19.2         2               1
393                  */
394                 if (fclk_rate > 12000000)
395                         psc = fclk_rate / 12000000;
396         }
397
398         if (!(omap->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
399
400                 /*
401                  * HSI2C controller internal clk rate should be 19.2 Mhz for
402                  * HS and for all modes on 2430. On 34xx we can use lower rate
403                  * to get longer filter period for better noise suppression.
404                  * The filter is iclk (fclk for HS) period.
405                  */
406                 if (omap->speed > 400 ||
407                                omap->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
408                         internal_clk = 19200;
409                 else if (omap->speed > 100)
410                         internal_clk = 9600;
411                 else
412                         internal_clk = 4000;
413                 fclk = clk_get(omap->dev, "fck");
414                 if (IS_ERR(fclk)) {
415                         error = PTR_ERR(fclk);
416                         dev_err(omap->dev, "could not get fck: %i\n", error);
417
418                         return error;
419                 }
420                 fclk_rate = clk_get_rate(fclk) / 1000;
421                 clk_put(fclk);
422
423                 /* Compute prescaler divisor */
424                 psc = fclk_rate / internal_clk;
425                 psc = psc - 1;
426
427                 /* If configured for High Speed */
428                 if (omap->speed > 400) {
429                         unsigned long scl;
430
431                         /* For first phase of HS mode */
432                         scl = internal_clk / 400;
433                         fsscll = scl - (scl / 3) - 7;
434                         fssclh = (scl / 3) - 5;
435
436                         /* For second phase of HS mode */
437                         scl = fclk_rate / omap->speed;
438                         hsscll = scl - (scl / 3) - 7;
439                         hssclh = (scl / 3) - 5;
440                 } else if (omap->speed > 100) {
441                         unsigned long scl;
442
443                         /* Fast mode */
444                         scl = internal_clk / omap->speed;
445                         fsscll = scl - (scl / 3) - 7;
446                         fssclh = (scl / 3) - 5;
447                 } else {
448                         /* Standard mode */
449                         fsscll = internal_clk / (omap->speed * 2) - 7;
450                         fssclh = internal_clk / (omap->speed * 2) - 5;
451                 }
452                 scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
453                 sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
454         } else {
455                 /* Program desired operating rate */
456                 fclk_rate /= (psc + 1) * 1000;
457                 if (psc > 2)
458                         psc = 2;
459                 scll = fclk_rate / (omap->speed * 2) - 7 + psc;
460                 sclh = fclk_rate / (omap->speed * 2) - 7 + psc;
461         }
462
463         omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
464                         OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
465                         OMAP_I2C_IE_AL)  | ((omap->fifo_size) ?
466                                 (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
467
468         omap->pscstate = psc;
469         omap->scllstate = scll;
470         omap->sclhstate = sclh;
471
472         if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) {
473                 /* Not implemented */
474                 omap->bb_valid = 1;
475         }
476
477         __omap_i2c_init(omap);
478
479         return 0;
480 }
481
482 /*
483  * Try bus recovery, but only if SDA is actually low.
484  */
485 static int omap_i2c_recover_bus(struct omap_i2c_dev *omap)
486 {
487         u16 systest;
488
489         systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
490         if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
491             (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC))
492                 return 0; /* bus seems to already be fine */
493         if (!(systest & OMAP_I2C_SYSTEST_SCL_I_FUNC))
494                 return -EBUSY; /* recovery would not fix SCL */
495         return i2c_recover_bus(&omap->adapter);
496 }
497
498 /*
499  * Waiting on Bus Busy
500  */
501 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *omap)
502 {
503         unsigned long timeout;
504
505         timeout = jiffies + OMAP_I2C_TIMEOUT;
506         while (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
507                 if (time_after(jiffies, timeout))
508                         return omap_i2c_recover_bus(omap);
509                 msleep(1);
510         }
511
512         return 0;
513 }
514
515 /*
516  * Wait while BB-bit doesn't reflect the I2C bus state
517  *
518  * In a multimaster environment, after IP software reset, BB-bit value doesn't
519  * correspond to the current bus state. It may happen what BB-bit will be 0,
520  * while the bus is busy due to another I2C master activity.
521  * Here are BB-bit values after reset:
522  *     SDA   SCL   BB   NOTES
523  *       0     0    0   1, 2
524  *       1     0    0   1, 2
525  *       0     1    1
526  *       1     1    0   3
527  * Later, if IP detect SDA=0 and SCL=1 (ACK) or SDA 1->0 while SCL=1 (START)
528  * combinations on the bus, it set BB-bit to 1.
529  * If IP detect SDA 0->1 while SCL=1 (STOP) combination on the bus,
530  * it set BB-bit to 0 and BF to 1.
531  * BB and BF bits correctly tracks the bus state while IP is suspended
532  * BB bit became valid on the next FCLK clock after CON_EN bit set
533  *
534  * NOTES:
535  * 1. Any transfer started when BB=0 and bus is busy wouldn't be
536  *    completed by IP and results in controller timeout.
537  * 2. Any transfer started when BB=0 and SCL=0 results in IP
538  *    starting to drive SDA low. In that case IP corrupt data
539  *    on the bus.
540  * 3. Any transfer started in the middle of another master's transfer
541  *    results in unpredictable results and data corruption
542  */
543 static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *omap)
544 {
545         unsigned long bus_free_timeout = 0;
546         unsigned long timeout;
547         int bus_free = 0;
548         u16 stat, systest;
549
550         if (omap->bb_valid)
551                 return 0;
552
553         timeout = jiffies + OMAP_I2C_TIMEOUT;
554         while (1) {
555                 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
556                 /*
557                  * We will see BB or BF event in a case IP had detected any
558                  * activity on the I2C bus. Now IP correctly tracks the bus
559                  * state. BB-bit value is valid.
560                  */
561                 if (stat & (OMAP_I2C_STAT_BB | OMAP_I2C_STAT_BF))
562                         break;
563
564                 /*
565                  * Otherwise, we must look signals on the bus to make
566                  * the right decision.
567                  */
568                 systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
569                 if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
570                     (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) {
571                         if (!bus_free) {
572                                 bus_free_timeout = jiffies +
573                                         OMAP_I2C_BUS_FREE_TIMEOUT;
574                                 bus_free = 1;
575                         }
576
577                         /*
578                          * SDA and SCL lines was high for 10 ms without bus
579                          * activity detected. The bus is free. Consider
580                          * BB-bit value is valid.
581                          */
582                         if (time_after(jiffies, bus_free_timeout))
583                                 break;
584                 } else {
585                         bus_free = 0;
586                 }
587
588                 if (time_after(jiffies, timeout)) {
589                         /*
590                          * SDA or SCL were low for the entire timeout without
591                          * any activity detected. Most likely, a slave is
592                          * locking up the bus with no master driving the clock.
593                          */
594                         dev_warn(omap->dev, "timeout waiting for bus ready\n");
595                         return omap_i2c_recover_bus(omap);
596                 }
597
598                 msleep(1);
599         }
600
601         omap->bb_valid = 1;
602         return 0;
603 }
604
605 static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx)
606 {
607         u16             buf;
608
609         if (omap->flags & OMAP_I2C_FLAG_NO_FIFO)
610                 return;
611
612         /*
613          * Set up notification threshold based on message size. We're doing
614          * this to try and avoid draining feature as much as possible. Whenever
615          * we have big messages to transfer (bigger than our total fifo size)
616          * then we might use draining feature to transfer the remaining bytes.
617          */
618
619         omap->threshold = clamp(size, (u8) 1, omap->fifo_size);
620
621         buf = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
622
623         if (is_rx) {
624                 /* Clear RX Threshold */
625                 buf &= ~(0x3f << 8);
626                 buf |= ((omap->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
627         } else {
628                 /* Clear TX Threshold */
629                 buf &= ~0x3f;
630                 buf |= (omap->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
631         }
632
633         omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, buf);
634
635         if (omap->rev < OMAP_I2C_REV_ON_3630)
636                 omap->b_hw = 1; /* Enable hardware fixes */
637
638         /* calculate wakeup latency constraint for MPU */
639         if (omap->set_mpu_wkup_lat != NULL)
640                 omap->latency = (1000000 * omap->threshold) /
641                         (1000 * omap->speed / 8);
642 }
643
644 static void omap_i2c_wait(struct omap_i2c_dev *omap)
645 {
646         u16 stat;
647         u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
648         int count = 0;
649
650         do {
651                 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
652                 count++;
653         } while (!(stat & mask) && count < 5);
654 }
655
656 /*
657  * Low level master read/write transaction.
658  */
659 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
660                              struct i2c_msg *msg, int stop, bool polling)
661 {
662         struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
663         unsigned long timeout;
664         u16 w;
665         int ret;
666
667         dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
668                 msg->addr, msg->len, msg->flags, stop);
669
670         omap->receiver = !!(msg->flags & I2C_M_RD);
671         omap_i2c_resize_fifo(omap, msg->len, omap->receiver);
672
673         omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr);
674
675         /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
676         omap->buf = msg->buf;
677         omap->buf_len = msg->len;
678
679         /* make sure writes to omap->buf_len are ordered */
680         barrier();
681
682         omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len);
683
684         /* Clear the FIFO Buffers */
685         w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
686         w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
687         omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w);
688
689         if (!polling)
690                 reinit_completion(&omap->cmd_complete);
691         omap->cmd_err = 0;
692
693         w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
694
695         /* High speed configuration */
696         if (omap->speed > 400)
697                 w |= OMAP_I2C_CON_OPMODE_HS;
698
699         if (msg->flags & I2C_M_STOP)
700                 stop = 1;
701         if (msg->flags & I2C_M_TEN)
702                 w |= OMAP_I2C_CON_XA;
703         if (!(msg->flags & I2C_M_RD))
704                 w |= OMAP_I2C_CON_TRX;
705
706         if (!omap->b_hw && stop)
707                 w |= OMAP_I2C_CON_STP;
708         /*
709          * NOTE: STAT_BB bit could became 1 here if another master occupy
710          * the bus. IP successfully complete transfer when the bus will be
711          * free again (BB reset to 0).
712          */
713         omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
714
715         /*
716          * Don't write stt and stp together on some hardware.
717          */
718         if (omap->b_hw && stop) {
719                 unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
720                 u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
721                 while (con & OMAP_I2C_CON_STT) {
722                         con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
723
724                         /* Let the user know if i2c is in a bad state */
725                         if (time_after(jiffies, delay)) {
726                                 dev_err(omap->dev, "controller timed out "
727                                 "waiting for start condition to finish\n");
728                                 return -ETIMEDOUT;
729                         }
730                         cpu_relax();
731                 }
732
733                 w |= OMAP_I2C_CON_STP;
734                 w &= ~OMAP_I2C_CON_STT;
735                 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
736         }
737
738         /*
739          * REVISIT: We should abort the transfer on signals, but the bus goes
740          * into arbitration and we're currently unable to recover from it.
741          */
742         if (!polling) {
743                 timeout = wait_for_completion_timeout(&omap->cmd_complete,
744                                                       OMAP_I2C_TIMEOUT);
745         } else {
746                 do {
747                         omap_i2c_wait(omap);
748                         ret = omap_i2c_xfer_data(omap);
749                 } while (ret == -EAGAIN);
750
751                 timeout = !ret;
752         }
753
754         if (timeout == 0) {
755                 dev_err(omap->dev, "controller timed out\n");
756                 omap_i2c_reset(omap);
757                 __omap_i2c_init(omap);
758                 return -ETIMEDOUT;
759         }
760
761         if (likely(!omap->cmd_err))
762                 return 0;
763
764         /* We have an error */
765         if (omap->cmd_err & (OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) {
766                 omap_i2c_reset(omap);
767                 __omap_i2c_init(omap);
768                 return -EIO;
769         }
770
771         if (omap->cmd_err & OMAP_I2C_STAT_AL)
772                 return -EAGAIN;
773
774         if (omap->cmd_err & OMAP_I2C_STAT_NACK) {
775                 if (msg->flags & I2C_M_IGNORE_NAK)
776                         return 0;
777
778                 w = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
779                 w |= OMAP_I2C_CON_STP;
780                 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
781                 return -EREMOTEIO;
782         }
783         return -EIO;
784 }
785
786
787 /*
788  * Prepare controller for a transaction and call omap_i2c_xfer_msg
789  * to do the work during IRQ processing.
790  */
791 static int
792 omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num,
793                      bool polling)
794 {
795         struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
796         int i;
797         int r;
798
799         r = pm_runtime_get_sync(omap->dev);
800         if (r < 0)
801                 goto out;
802
803         r = omap_i2c_wait_for_bb_valid(omap);
804         if (r < 0)
805                 goto out;
806
807         r = omap_i2c_wait_for_bb(omap);
808         if (r < 0)
809                 goto out;
810
811         if (omap->set_mpu_wkup_lat != NULL)
812                 omap->set_mpu_wkup_lat(omap->dev, omap->latency);
813
814         for (i = 0; i < num; i++) {
815                 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)),
816                                       polling);
817                 if (r != 0)
818                         break;
819         }
820
821         if (r == 0)
822                 r = num;
823
824         omap_i2c_wait_for_bb(omap);
825
826         if (omap->set_mpu_wkup_lat != NULL)
827                 omap->set_mpu_wkup_lat(omap->dev, -1);
828
829 out:
830         pm_runtime_mark_last_busy(omap->dev);
831         pm_runtime_put_autosuspend(omap->dev);
832         return r;
833 }
834
835 static int
836 omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
837 {
838         return omap_i2c_xfer_common(adap, msgs, num, false);
839 }
840
841 static int
842 omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
843 {
844         return omap_i2c_xfer_common(adap, msgs, num, true);
845 }
846
847 static u32
848 omap_i2c_func(struct i2c_adapter *adap)
849 {
850         return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
851                I2C_FUNC_PROTOCOL_MANGLING;
852 }
853
854 static inline void
855 omap_i2c_complete_cmd(struct omap_i2c_dev *omap, u16 err)
856 {
857         omap->cmd_err |= err;
858         complete(&omap->cmd_complete);
859 }
860
861 static inline void
862 omap_i2c_ack_stat(struct omap_i2c_dev *omap, u16 stat)
863 {
864         omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, stat);
865 }
866
867 static inline void i2c_omap_errata_i207(struct omap_i2c_dev *omap, u16 stat)
868 {
869         /*
870          * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
871          * Not applicable for OMAP4.
872          * Under certain rare conditions, RDR could be set again
873          * when the bus is busy, then ignore the interrupt and
874          * clear the interrupt.
875          */
876         if (stat & OMAP_I2C_STAT_RDR) {
877                 /* Step 1: If RDR is set, clear it */
878                 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
879
880                 /* Step 2: */
881                 if (!(omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
882                                                 & OMAP_I2C_STAT_BB)) {
883
884                         /* Step 3: */
885                         if (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
886                                                 & OMAP_I2C_STAT_RDR) {
887                                 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
888                                 dev_dbg(omap->dev, "RDR when bus is busy.\n");
889                         }
890
891                 }
892         }
893 }
894
895 /* rev1 devices are apparently only on some 15xx */
896 #ifdef CONFIG_ARCH_OMAP15XX
897
898 static irqreturn_t
899 omap_i2c_omap1_isr(int this_irq, void *dev_id)
900 {
901         struct omap_i2c_dev *omap = dev_id;
902         u16 iv, w;
903
904         if (pm_runtime_suspended(omap->dev))
905                 return IRQ_NONE;
906
907         iv = omap_i2c_read_reg(omap, OMAP_I2C_IV_REG);
908         switch (iv) {
909         case 0x00:      /* None */
910                 break;
911         case 0x01:      /* Arbitration lost */
912                 dev_err(omap->dev, "Arbitration lost\n");
913                 omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_AL);
914                 break;
915         case 0x02:      /* No acknowledgement */
916                 omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_NACK);
917                 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
918                 break;
919         case 0x03:      /* Register access ready */
920                 omap_i2c_complete_cmd(omap, 0);
921                 break;
922         case 0x04:      /* Receive data ready */
923                 if (omap->buf_len) {
924                         w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
925                         *omap->buf++ = w;
926                         omap->buf_len--;
927                         if (omap->buf_len) {
928                                 *omap->buf++ = w >> 8;
929                                 omap->buf_len--;
930                         }
931                 } else
932                         dev_err(omap->dev, "RRDY IRQ while no data requested\n");
933                 break;
934         case 0x05:      /* Transmit data ready */
935                 if (omap->buf_len) {
936                         w = *omap->buf++;
937                         omap->buf_len--;
938                         if (omap->buf_len) {
939                                 w |= *omap->buf++ << 8;
940                                 omap->buf_len--;
941                         }
942                         omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
943                 } else
944                         dev_err(omap->dev, "XRDY IRQ while no data to send\n");
945                 break;
946         default:
947                 return IRQ_NONE;
948         }
949
950         return IRQ_HANDLED;
951 }
952 #else
953 #define omap_i2c_omap1_isr              NULL
954 #endif
955
956 /*
957  * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing
958  * data to DATA_REG. Otherwise some data bytes can be lost while transferring
959  * them from the memory to the I2C interface.
960  */
961 static int errata_omap3_i462(struct omap_i2c_dev *omap)
962 {
963         unsigned long timeout = 10000;
964         u16 stat;
965
966         do {
967                 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
968                 if (stat & OMAP_I2C_STAT_XUDF)
969                         break;
970
971                 if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
972                         omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_XRDY |
973                                                         OMAP_I2C_STAT_XDR));
974                         if (stat & OMAP_I2C_STAT_NACK) {
975                                 omap->cmd_err |= OMAP_I2C_STAT_NACK;
976                                 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
977                         }
978
979                         if (stat & OMAP_I2C_STAT_AL) {
980                                 dev_err(omap->dev, "Arbitration lost\n");
981                                 omap->cmd_err |= OMAP_I2C_STAT_AL;
982                                 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
983                         }
984
985                         return -EIO;
986                 }
987
988                 cpu_relax();
989         } while (--timeout);
990
991         if (!timeout) {
992                 dev_err(omap->dev, "timeout waiting on XUDF bit\n");
993                 return 0;
994         }
995
996         return 0;
997 }
998
999 static void omap_i2c_receive_data(struct omap_i2c_dev *omap, u8 num_bytes,
1000                 bool is_rdr)
1001 {
1002         u16             w;
1003
1004         while (num_bytes--) {
1005                 w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
1006                 *omap->buf++ = w;
1007                 omap->buf_len--;
1008
1009                 /*
1010                  * Data reg in 2430, omap3 and
1011                  * omap4 is 8 bit wide
1012                  */
1013                 if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
1014                         *omap->buf++ = w >> 8;
1015                         omap->buf_len--;
1016                 }
1017         }
1018 }
1019
1020 static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes,
1021                 bool is_xdr)
1022 {
1023         u16             w;
1024
1025         while (num_bytes--) {
1026                 w = *omap->buf++;
1027                 omap->buf_len--;
1028
1029                 /*
1030                  * Data reg in 2430, omap3 and
1031                  * omap4 is 8 bit wide
1032                  */
1033                 if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
1034                         w |= *omap->buf++ << 8;
1035                         omap->buf_len--;
1036                 }
1037
1038                 if (omap->errata & I2C_OMAP_ERRATA_I462) {
1039                         int ret;
1040
1041                         ret = errata_omap3_i462(omap);
1042                         if (ret < 0)
1043                                 return ret;
1044                 }
1045
1046                 omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
1047         }
1048
1049         return 0;
1050 }
1051
1052 static irqreturn_t
1053 omap_i2c_isr(int irq, void *dev_id)
1054 {
1055         struct omap_i2c_dev *omap = dev_id;
1056         irqreturn_t ret = IRQ_HANDLED;
1057         u16 mask;
1058         u16 stat;
1059
1060         stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
1061         mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
1062
1063         if (stat & mask)
1064                 ret = IRQ_WAKE_THREAD;
1065
1066         return ret;
1067 }
1068
1069 static int omap_i2c_xfer_data(struct omap_i2c_dev *omap)
1070 {
1071         u16 bits;
1072         u16 stat;
1073         int err = 0, count = 0;
1074
1075         do {
1076                 bits = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
1077                 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
1078                 stat &= bits;
1079
1080                 /* If we're in receiver mode, ignore XDR/XRDY */
1081                 if (omap->receiver)
1082                         stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
1083                 else
1084                         stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
1085
1086                 if (!stat) {
1087                         /* my work here is done */
1088                         err = -EAGAIN;
1089                         break;
1090                 }
1091
1092                 dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat);
1093                 if (count++ == 100) {
1094                         dev_warn(omap->dev, "Too much work in one IRQ\n");
1095                         break;
1096                 }
1097
1098                 if (stat & OMAP_I2C_STAT_NACK) {
1099                         err |= OMAP_I2C_STAT_NACK;
1100                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
1101                 }
1102
1103                 if (stat & OMAP_I2C_STAT_AL) {
1104                         dev_err(omap->dev, "Arbitration lost\n");
1105                         err |= OMAP_I2C_STAT_AL;
1106                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
1107                 }
1108
1109                 /*
1110                  * ProDB0017052: Clear ARDY bit twice
1111                  */
1112                 if (stat & OMAP_I2C_STAT_ARDY)
1113                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ARDY);
1114
1115                 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
1116                                         OMAP_I2C_STAT_AL)) {
1117                         omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_RRDY |
1118                                                 OMAP_I2C_STAT_RDR |
1119                                                 OMAP_I2C_STAT_XRDY |
1120                                                 OMAP_I2C_STAT_XDR |
1121                                                 OMAP_I2C_STAT_ARDY));
1122                         break;
1123                 }
1124
1125                 if (stat & OMAP_I2C_STAT_RDR) {
1126                         u8 num_bytes = 1;
1127
1128                         if (omap->fifo_size)
1129                                 num_bytes = omap->buf_len;
1130
1131                         if (omap->errata & I2C_OMAP_ERRATA_I207) {
1132                                 i2c_omap_errata_i207(omap, stat);
1133                                 num_bytes = (omap_i2c_read_reg(omap,
1134                                         OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F;
1135                         }
1136
1137                         omap_i2c_receive_data(omap, num_bytes, true);
1138                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
1139                         continue;
1140                 }
1141
1142                 if (stat & OMAP_I2C_STAT_RRDY) {
1143                         u8 num_bytes = 1;
1144
1145                         if (omap->threshold)
1146                                 num_bytes = omap->threshold;
1147
1148                         omap_i2c_receive_data(omap, num_bytes, false);
1149                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RRDY);
1150                         continue;
1151                 }
1152
1153                 if (stat & OMAP_I2C_STAT_XDR) {
1154                         u8 num_bytes = 1;
1155                         int ret;
1156
1157                         if (omap->fifo_size)
1158                                 num_bytes = omap->buf_len;
1159
1160                         ret = omap_i2c_transmit_data(omap, num_bytes, true);
1161                         if (ret < 0)
1162                                 break;
1163
1164                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XDR);
1165                         continue;
1166                 }
1167
1168                 if (stat & OMAP_I2C_STAT_XRDY) {
1169                         u8 num_bytes = 1;
1170                         int ret;
1171
1172                         if (omap->threshold)
1173                                 num_bytes = omap->threshold;
1174
1175                         ret = omap_i2c_transmit_data(omap, num_bytes, false);
1176                         if (ret < 0)
1177                                 break;
1178
1179                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XRDY);
1180                         continue;
1181                 }
1182
1183                 if (stat & OMAP_I2C_STAT_ROVR) {
1184                         dev_err(omap->dev, "Receive overrun\n");
1185                         err |= OMAP_I2C_STAT_ROVR;
1186                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ROVR);
1187                         break;
1188                 }
1189
1190                 if (stat & OMAP_I2C_STAT_XUDF) {
1191                         dev_err(omap->dev, "Transmit underflow\n");
1192                         err |= OMAP_I2C_STAT_XUDF;
1193                         omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XUDF);
1194                         break;
1195                 }
1196         } while (stat);
1197
1198         return err;
1199 }
1200
1201 static irqreturn_t
1202 omap_i2c_isr_thread(int this_irq, void *dev_id)
1203 {
1204         int ret;
1205         struct omap_i2c_dev *omap = dev_id;
1206
1207         ret = omap_i2c_xfer_data(omap);
1208         if (ret != -EAGAIN)
1209                 omap_i2c_complete_cmd(omap, ret);
1210
1211         return IRQ_HANDLED;
1212 }
1213
1214 static const struct i2c_algorithm omap_i2c_algo = {
1215         .master_xfer    = omap_i2c_xfer_irq,
1216         .master_xfer_atomic     = omap_i2c_xfer_polling,
1217         .functionality  = omap_i2c_func,
1218 };
1219
1220 static const struct i2c_adapter_quirks omap_i2c_quirks = {
1221         .flags = I2C_AQ_NO_ZERO_LEN,
1222 };
1223
1224 #ifdef CONFIG_OF
1225 static struct omap_i2c_bus_platform_data omap2420_pdata = {
1226         .rev = OMAP_I2C_IP_VERSION_1,
1227         .flags = OMAP_I2C_FLAG_NO_FIFO |
1228                         OMAP_I2C_FLAG_SIMPLE_CLOCK |
1229                         OMAP_I2C_FLAG_16BIT_DATA_REG |
1230                         OMAP_I2C_FLAG_BUS_SHIFT_2,
1231 };
1232
1233 static struct omap_i2c_bus_platform_data omap2430_pdata = {
1234         .rev = OMAP_I2C_IP_VERSION_1,
1235         .flags = OMAP_I2C_FLAG_BUS_SHIFT_2 |
1236                         OMAP_I2C_FLAG_FORCE_19200_INT_CLK,
1237 };
1238
1239 static struct omap_i2c_bus_platform_data omap3_pdata = {
1240         .rev = OMAP_I2C_IP_VERSION_1,
1241         .flags = OMAP_I2C_FLAG_BUS_SHIFT_2,
1242 };
1243
1244 static struct omap_i2c_bus_platform_data omap4_pdata = {
1245         .rev = OMAP_I2C_IP_VERSION_2,
1246 };
1247
1248 static const struct of_device_id omap_i2c_of_match[] = {
1249         {
1250                 .compatible = "ti,omap4-i2c",
1251                 .data = &omap4_pdata,
1252         },
1253         {
1254                 .compatible = "ti,omap3-i2c",
1255                 .data = &omap3_pdata,
1256         },
1257         {
1258                 .compatible = "ti,omap2430-i2c",
1259                 .data = &omap2430_pdata,
1260         },
1261         {
1262                 .compatible = "ti,omap2420-i2c",
1263                 .data = &omap2420_pdata,
1264         },
1265         { },
1266 };
1267 MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
1268 #endif
1269
1270 #define OMAP_I2C_SCHEME(rev)            ((rev & 0xc000) >> 14)
1271
1272 #define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4)
1273 #define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf)
1274
1275 #define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7)
1276 #define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f)
1277 #define OMAP_I2C_SCHEME_0               0
1278 #define OMAP_I2C_SCHEME_1               1
1279
1280 static int omap_i2c_get_scl(struct i2c_adapter *adap)
1281 {
1282         struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1283         u32 reg;
1284
1285         reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1286
1287         return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;
1288 }
1289
1290 static int omap_i2c_get_sda(struct i2c_adapter *adap)
1291 {
1292         struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1293         u32 reg;
1294
1295         reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1296
1297         return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;
1298 }
1299
1300 static void omap_i2c_set_scl(struct i2c_adapter *adap, int val)
1301 {
1302         struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1303         u32 reg;
1304
1305         reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1306         if (val)
1307                 reg |= OMAP_I2C_SYSTEST_SCL_O;
1308         else
1309                 reg &= ~OMAP_I2C_SYSTEST_SCL_O;
1310         omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
1311 }
1312
1313 static void omap_i2c_prepare_recovery(struct i2c_adapter *adap)
1314 {
1315         struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1316         u32 reg;
1317
1318         reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1319         /* enable test mode */
1320         reg |= OMAP_I2C_SYSTEST_ST_EN;
1321         /* select SDA/SCL IO mode */
1322         reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT;
1323         /* set SCL to high-impedance state (reset value is 0) */
1324         reg |= OMAP_I2C_SYSTEST_SCL_O;
1325         /* set SDA to high-impedance state (reset value is 0) */
1326         reg |= OMAP_I2C_SYSTEST_SDA_O;
1327         omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
1328 }
1329
1330 static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap)
1331 {
1332         struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1333         u32 reg;
1334
1335         reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1336         /* restore reset values */
1337         reg &= ~OMAP_I2C_SYSTEST_ST_EN;
1338         reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK;
1339         reg &= ~OMAP_I2C_SYSTEST_SCL_O;
1340         reg &= ~OMAP_I2C_SYSTEST_SDA_O;
1341         omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
1342 }
1343
1344 static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {
1345         .get_scl                = omap_i2c_get_scl,
1346         .get_sda                = omap_i2c_get_sda,
1347         .set_scl                = omap_i2c_set_scl,
1348         .prepare_recovery       = omap_i2c_prepare_recovery,
1349         .unprepare_recovery     = omap_i2c_unprepare_recovery,
1350         .recover_bus            = i2c_generic_scl_recovery,
1351 };
1352
1353 static int
1354 omap_i2c_probe(struct platform_device *pdev)
1355 {
1356         struct omap_i2c_dev     *omap;
1357         struct i2c_adapter      *adap;
1358         struct resource         *mem;
1359         const struct omap_i2c_bus_platform_data *pdata =
1360                 dev_get_platdata(&pdev->dev);
1361         struct device_node      *node = pdev->dev.of_node;
1362         const struct of_device_id *match;
1363         int irq;
1364         int r;
1365         u32 rev;
1366         u16 minor, major;
1367
1368         irq = platform_get_irq(pdev, 0);
1369         if (irq < 0) {
1370                 dev_err(&pdev->dev, "no irq resource?\n");
1371                 return irq;
1372         }
1373
1374         omap = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
1375         if (!omap)
1376                 return -ENOMEM;
1377
1378         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1379         omap->base = devm_ioremap_resource(&pdev->dev, mem);
1380         if (IS_ERR(omap->base))
1381                 return PTR_ERR(omap->base);
1382
1383         match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
1384         if (match) {
1385                 u32 freq = 100000; /* default to 100000 Hz */
1386
1387                 pdata = match->data;
1388                 omap->flags = pdata->flags;
1389
1390                 of_property_read_u32(node, "clock-frequency", &freq);
1391                 /* convert DT freq value in Hz into kHz for speed */
1392                 omap->speed = freq / 1000;
1393         } else if (pdata != NULL) {
1394                 omap->speed = pdata->clkrate;
1395                 omap->flags = pdata->flags;
1396                 omap->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
1397         }
1398
1399         omap->dev = &pdev->dev;
1400         omap->irq = irq;
1401
1402         platform_set_drvdata(pdev, omap);
1403         init_completion(&omap->cmd_complete);
1404
1405         omap->reg_shift = (omap->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
1406
1407         pm_runtime_enable(omap->dev);
1408         pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
1409         pm_runtime_use_autosuspend(omap->dev);
1410
1411         r = pm_runtime_get_sync(omap->dev);
1412         if (r < 0)
1413                 goto err_free_mem;
1414
1415         /*
1416          * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
1417          * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset.
1418          * Also since the omap_i2c_read_reg uses reg_map_ip_* a
1419          * readw_relaxed is done.
1420          */
1421         rev = readw_relaxed(omap->base + 0x04);
1422
1423         omap->scheme = OMAP_I2C_SCHEME(rev);
1424         switch (omap->scheme) {
1425         case OMAP_I2C_SCHEME_0:
1426                 omap->regs = (u8 *)reg_map_ip_v1;
1427                 omap->rev = omap_i2c_read_reg(omap, OMAP_I2C_REV_REG);
1428                 minor = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
1429                 major = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
1430                 break;
1431         case OMAP_I2C_SCHEME_1:
1432                 /* FALLTHROUGH */
1433         default:
1434                 omap->regs = (u8 *)reg_map_ip_v2;
1435                 rev = (rev << 16) |
1436                         omap_i2c_read_reg(omap, OMAP_I2C_IP_V2_REVNB_LO);
1437                 minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev);
1438                 major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev);
1439                 omap->rev = rev;
1440         }
1441
1442         omap->errata = 0;
1443
1444         if (omap->rev >= OMAP_I2C_REV_ON_2430 &&
1445                         omap->rev < OMAP_I2C_REV_ON_4430_PLUS)
1446                 omap->errata |= I2C_OMAP_ERRATA_I207;
1447
1448         if (omap->rev <= OMAP_I2C_REV_ON_3430_3530)
1449                 omap->errata |= I2C_OMAP_ERRATA_I462;
1450
1451         if (!(omap->flags & OMAP_I2C_FLAG_NO_FIFO)) {
1452                 u16 s;
1453
1454                 /* Set up the fifo size - Get total size */
1455                 s = (omap_i2c_read_reg(omap, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
1456                 omap->fifo_size = 0x8 << s;
1457
1458                 /*
1459                  * Set up notification threshold as half the total available
1460                  * size. This is to ensure that we can handle the status on int
1461                  * call back latencies.
1462                  */
1463
1464                 omap->fifo_size = (omap->fifo_size / 2);
1465
1466                 if (omap->rev < OMAP_I2C_REV_ON_3630)
1467                         omap->b_hw = 1; /* Enable hardware fixes */
1468
1469                 /* calculate wakeup latency constraint for MPU */
1470                 if (omap->set_mpu_wkup_lat != NULL)
1471                         omap->latency = (1000000 * omap->fifo_size) /
1472                                        (1000 * omap->speed / 8);
1473         }
1474
1475         /* reset ASAP, clearing any IRQs */
1476         omap_i2c_init(omap);
1477
1478         if (omap->rev < OMAP_I2C_OMAP1_REV_2)
1479                 r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr,
1480                                 IRQF_NO_SUSPEND, pdev->name, omap);
1481         else
1482                 r = devm_request_threaded_irq(&pdev->dev, omap->irq,
1483                                 omap_i2c_isr, omap_i2c_isr_thread,
1484                                 IRQF_NO_SUSPEND | IRQF_ONESHOT,
1485                                 pdev->name, omap);
1486
1487         if (r) {
1488                 dev_err(omap->dev, "failure requesting irq %i\n", omap->irq);
1489                 goto err_unuse_clocks;
1490         }
1491
1492         adap = &omap->adapter;
1493         i2c_set_adapdata(adap, omap);
1494         adap->owner = THIS_MODULE;
1495         adap->class = I2C_CLASS_DEPRECATED;
1496         strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
1497         adap->algo = &omap_i2c_algo;
1498         adap->quirks = &omap_i2c_quirks;
1499         adap->dev.parent = &pdev->dev;
1500         adap->dev.of_node = pdev->dev.of_node;
1501         adap->bus_recovery_info = &omap_i2c_bus_recovery_info;
1502
1503         /* i2c device drivers may be active on return from add_adapter() */
1504         adap->nr = pdev->id;
1505         r = i2c_add_numbered_adapter(adap);
1506         if (r)
1507                 goto err_unuse_clocks;
1508
1509         dev_info(omap->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr,
1510                  major, minor, omap->speed);
1511
1512         pm_runtime_mark_last_busy(omap->dev);
1513         pm_runtime_put_autosuspend(omap->dev);
1514
1515         return 0;
1516
1517 err_unuse_clocks:
1518         omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
1519         pm_runtime_dont_use_autosuspend(omap->dev);
1520         pm_runtime_put_sync(omap->dev);
1521         pm_runtime_disable(&pdev->dev);
1522 err_free_mem:
1523
1524         return r;
1525 }
1526
1527 static int omap_i2c_remove(struct platform_device *pdev)
1528 {
1529         struct omap_i2c_dev     *omap = platform_get_drvdata(pdev);
1530         int ret;
1531
1532         i2c_del_adapter(&omap->adapter);
1533         ret = pm_runtime_get_sync(&pdev->dev);
1534         if (ret < 0)
1535                 return ret;
1536
1537         omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
1538         pm_runtime_dont_use_autosuspend(&pdev->dev);
1539         pm_runtime_put_sync(&pdev->dev);
1540         pm_runtime_disable(&pdev->dev);
1541         return 0;
1542 }
1543
1544 static int __maybe_unused omap_i2c_runtime_suspend(struct device *dev)
1545 {
1546         struct omap_i2c_dev *omap = dev_get_drvdata(dev);
1547
1548         omap->iestate = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
1549
1550         if (omap->scheme == OMAP_I2C_SCHEME_0)
1551                 omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, 0);
1552         else
1553                 omap_i2c_write_reg(omap, OMAP_I2C_IP_V2_IRQENABLE_CLR,
1554                                    OMAP_I2C_IP_V2_INTERRUPTS_MASK);
1555
1556         if (omap->rev < OMAP_I2C_OMAP1_REV_2) {
1557                 omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); /* Read clears */
1558         } else {
1559                 omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, omap->iestate);
1560
1561                 /* Flush posted write */
1562                 omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
1563         }
1564
1565         pinctrl_pm_select_sleep_state(dev);
1566
1567         return 0;
1568 }
1569
1570 static int __maybe_unused omap_i2c_runtime_resume(struct device *dev)
1571 {
1572         struct omap_i2c_dev *omap = dev_get_drvdata(dev);
1573
1574         pinctrl_pm_select_default_state(dev);
1575
1576         if (!omap->regs)
1577                 return 0;
1578
1579         __omap_i2c_init(omap);
1580
1581         return 0;
1582 }
1583
1584 static const struct dev_pm_ops omap_i2c_pm_ops = {
1585         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1586                                       pm_runtime_force_resume)
1587         SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
1588                            omap_i2c_runtime_resume, NULL)
1589 };
1590
1591 static struct platform_driver omap_i2c_driver = {
1592         .probe          = omap_i2c_probe,
1593         .remove         = omap_i2c_remove,
1594         .driver         = {
1595                 .name   = "omap_i2c",
1596                 .pm     = &omap_i2c_pm_ops,
1597                 .of_match_table = of_match_ptr(omap_i2c_of_match),
1598         },
1599 };
1600
1601 /* I2C may be needed to bring up other drivers */
1602 static int __init
1603 omap_i2c_init_driver(void)
1604 {
1605         return platform_driver_register(&omap_i2c_driver);
1606 }
1607 subsys_initcall(omap_i2c_init_driver);
1608
1609 static void __exit omap_i2c_exit_driver(void)
1610 {
1611         platform_driver_unregister(&omap_i2c_driver);
1612 }
1613 module_exit(omap_i2c_exit_driver);
1614
1615 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
1616 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
1617 MODULE_LICENSE("GPL");
1618 MODULE_ALIAS("platform:omap_i2c");