arch/arm/mach-omap1/serial.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/arch/arm/mach-omap1/serial.c
   4  *
   5  * OMAP1 serial support.
   6  */
   7 #include <linux/gpio/machine.h>
   8 #include <linux/gpio/consumer.h>
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/irq.h>
  13 #include <linux/delay.h>
  14 #include <linux/serial.h>
  15 #include <linux/tty.h>
  16 #include <linux/serial_8250.h>
  17 #include <linux/serial_reg.h>
  18 #include <linux/clk.h>
  19 #include <linux/io.h>
  20
  21 #include <asm/mach-types.h>
  22
  23 #include "common.h"
  24 #include "serial.h"
  25 #include "mux.h"
  26 #include "pm.h"
  27 #include "soc.h"
  28
  29 static struct clk * uart1_ck;
  30 static struct clk * uart2_ck;
  31 static struct clk * uart3_ck;
  32
  33 static inline unsigned int omap_serial_in(struct plat_serial8250_port *up,
  34                                           int offset)
  35 {
  36         offset <<= up->regshift;
  37         return (unsigned int)__raw_readb(up->membase + offset);
  38 }
  39
  40 static inline void omap_serial_outp(struct plat_serial8250_port *p, int offset,
  41                                     int value)
  42 {
  43         offset <<= p->regshift;
  44         __raw_writeb(value, p->membase + offset);
  45 }
  46
  47 /*
  48  * Internal UARTs need to be initialized for the 8250 autoconfig to work
  49  * properly. Note that the TX watermark initialization may not be needed
  50  * once the 8250.c watermark handling code is merged.
  51  */
  52 static void __init omap_serial_reset(struct plat_serial8250_port *p)
  53 {
  54         omap_serial_outp(p, UART_OMAP_MDR1,
  55                         UART_OMAP_MDR1_DISABLE);        /* disable UART */
  56         omap_serial_outp(p, UART_OMAP_SCR, 0x08);       /* TX watermark */
  57         omap_serial_outp(p, UART_OMAP_MDR1,
  58                         UART_OMAP_MDR1_16X_MODE);       /* enable UART */
  59
  60         if (!cpu_is_omap15xx()) {
  61                 omap_serial_outp(p, UART_OMAP_SYSC, 0x01);
  62                 while (!(omap_serial_in(p, UART_OMAP_SYSC) & 0x01));
  63         }
  64 }
  65
  66 static struct plat_serial8250_port serial_platform_data[] = {
  67         {
  68                 .mapbase        = OMAP1_UART1_BASE,
  69                 .irq            = INT_UART1,
  70                 .flags          = UPF_BOOT_AUTOCONF,
  71                 .iotype         = UPIO_MEM,
  72                 .regshift       = 2,
  73                 .uartclk        = OMAP16XX_BASE_BAUD * 16,
  74         },
  75         {
  76                 .mapbase        = OMAP1_UART2_BASE,
  77                 .irq            = INT_UART2,
  78                 .flags          = UPF_BOOT_AUTOCONF,
  79                 .iotype         = UPIO_MEM,
  80                 .regshift       = 2,
  81                 .uartclk        = OMAP16XX_BASE_BAUD * 16,
  82         },
  83         {
  84                 .mapbase        = OMAP1_UART3_BASE,
  85                 .irq            = INT_UART3,
  86                 .flags          = UPF_BOOT_AUTOCONF,
  87                 .iotype         = UPIO_MEM,
  88                 .regshift       = 2,
  89                 .uartclk        = OMAP16XX_BASE_BAUD * 16,
  90         },
  91         { },
  92 };
  93
  94 static struct platform_device serial_device = {
  95         .name                   = "serial8250",
  96         .id                     = PLAT8250_DEV_PLATFORM,
  97         .dev                    = {
  98                 .platform_data  = serial_platform_data,
  99         },
 100 };
 101
 102 /*
 103  * Note that on Innovator-1510 UART2 pins conflict with USB2.
 104  * By default UART2 does not work on Innovator-1510 if you have
 105  * USB OHCI enabled. To use UART2, you must disable USB2 first.
 106  */
 107 void __init omap_serial_init(void)
 108 {
 109         int i;
 110
 111         if (cpu_is_omap15xx()) {
 112                 serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
 113                 serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
 114                 serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
 115         }
 116
 117         for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {
 118                 /* Static mapping, never released */
 119                 serial_platform_data[i].membase =
 120                         ioremap(serial_platform_data[i].mapbase, SZ_2K);
 121                 if (!serial_platform_data[i].membase) {
 122                         printk(KERN_ERR "Could not ioremap uart%i\n", i);
 123                         continue;
 124                 }
 125                 switch (i) {
 126                 case 0:
 127                         uart1_ck = clk_get(NULL, "uart1_ck");
 128                         if (IS_ERR(uart1_ck))
 129                                 printk("Could not get uart1_ck\n");
 130                         else {
 131                                 clk_prepare_enable(uart1_ck);
 132                                 if (cpu_is_omap15xx())
 133                                         clk_set_rate(uart1_ck, 12000000);
 134                         }
 135                         break;
 136                 case 1:
 137                         uart2_ck = clk_get(NULL, "uart2_ck");
 138                         if (IS_ERR(uart2_ck))
 139                                 printk("Could not get uart2_ck\n");
 140                         else {
 141                                 clk_prepare_enable(uart2_ck);
 142                                 if (cpu_is_omap15xx())
 143                                         clk_set_rate(uart2_ck, 12000000);
 144                                 else
 145                                         clk_set_rate(uart2_ck, 48000000);
 146                         }
 147                         break;
 148                 case 2:
 149                         uart3_ck = clk_get(NULL, "uart3_ck");
 150                         if (IS_ERR(uart3_ck))
 151                                 printk("Could not get uart3_ck\n");
 152                         else {
 153                                 clk_prepare_enable(uart3_ck);
 154                                 if (cpu_is_omap15xx())
 155                                         clk_set_rate(uart3_ck, 12000000);
 156                         }
 157                         break;
 158                 }
 159                 omap_serial_reset(&serial_platform_data[i]);
 160         }
 161 }
 162
 163 #ifdef CONFIG_OMAP_SERIAL_WAKE
 164
 165 static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
 166 {
 167         /* Need to do something with serial port right after wake-up? */
 168         return IRQ_HANDLED;
 169 }
 170
 171 /*
 172  * Reroutes serial RX lines to GPIO lines for the duration of
 173  * sleep to allow waking up the device from serial port even
 174  * in deep sleep.
 175  */
 176 void omap_serial_wake_trigger(int enable)
 177 {
 178         if (!cpu_is_omap16xx())
 179                 return;
 180
 181         if (uart1_ck != NULL) {
 182                 if (enable)
 183                         omap_cfg_reg(V14_16XX_GPIO37);
 184                 else
 185                         omap_cfg_reg(V14_16XX_UART1_RX);
 186         }
 187         if (uart2_ck != NULL) {
 188                 if (enable)
 189                         omap_cfg_reg(R9_16XX_GPIO18);
 190                 else
 191                         omap_cfg_reg(R9_16XX_UART2_RX);
 192         }
 193         if (uart3_ck != NULL) {
 194                 if (enable)
 195                         omap_cfg_reg(L14_16XX_GPIO49);
 196                 else
 197                         omap_cfg_reg(L14_16XX_UART3_RX);
 198         }
 199 }
 200
 201 static void __init omap_serial_set_port_wakeup(int idx)
 202 {
 203         struct gpio_desc *d;
 204         int ret;
 205
 206         d = gpiod_get_index(NULL, "wakeup", idx, GPIOD_IN);
 207         if (IS_ERR(d)) {
 208                 pr_err("Unable to get UART wakeup GPIO descriptor\n");
 209                 return;
 210         }
 211         ret = request_irq(gpiod_to_irq(d), &omap_serial_wake_interrupt,
 212                           IRQF_TRIGGER_RISING, "serial wakeup", NULL);
 213         if (ret) {
 214                 gpiod_put(d);
 215                 pr_err("No interrupt for UART%d wake GPIO\n", idx + 1);
 216                 return;
 217         }
 218         enable_irq_wake(gpiod_to_irq(d));
 219 }
 220
 221
 222 int __init omap_serial_wakeup_init(void)
 223 {
 224         if (!cpu_is_omap16xx())
 225                 return 0;
 226
 227         if (uart1_ck != NULL)
 228                 omap_serial_set_port_wakeup(0);
 229         if (uart2_ck != NULL)
 230                 omap_serial_set_port_wakeup(1);
 231         if (uart3_ck != NULL)
 232                 omap_serial_set_port_wakeup(2);
 233
 234         return 0;
 235 }
 236
 237 #endif  /* CONFIG_OMAP_SERIAL_WAKE */
 238
 239 static int __init omap_init(void)
 240 {
 241         if (!cpu_class_is_omap1())
 242                 return -ENODEV;
 243
 244         return platform_device_register(&serial_device);
 245 }
 246 arch_initcall(omap_init);