Merge tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[sfrench/cifs-2.6.git] / drivers / reset / reset-imx7.c
1 /*
2  * Copyright (c) 2017, Impinj, Inc.
3  *
4  * i.MX7 System Reset Controller (SRC) driver
5  *
6  * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  */
17
18 #include <linux/mfd/syscon.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/platform_device.h>
21 #include <linux/reset-controller.h>
22 #include <linux/regmap.h>
23 #include <dt-bindings/reset/imx7-reset.h>
24
25 struct imx7_src {
26         struct reset_controller_dev rcdev;
27         struct regmap *regmap;
28 };
29
30 enum imx7_src_registers {
31         SRC_A7RCR0              = 0x0004,
32         SRC_M4RCR               = 0x000c,
33         SRC_ERCR                = 0x0014,
34         SRC_HSICPHY_RCR         = 0x001c,
35         SRC_USBOPHY1_RCR        = 0x0020,
36         SRC_USBOPHY2_RCR        = 0x0024,
37         SRC_MIPIPHY_RCR         = 0x0028,
38         SRC_PCIEPHY_RCR         = 0x002c,
39         SRC_DDRC_RCR            = 0x1000,
40 };
41
42 struct imx7_src_signal {
43         unsigned int offset, bit;
44 };
45
46 static const struct imx7_src_signal imx7_src_signals[IMX7_RESET_NUM] = {
47         [IMX7_RESET_A7_CORE_POR_RESET0] = { SRC_A7RCR0, BIT(0) },
48         [IMX7_RESET_A7_CORE_POR_RESET1] = { SRC_A7RCR0, BIT(1) },
49         [IMX7_RESET_A7_CORE_RESET0]     = { SRC_A7RCR0, BIT(4) },
50         [IMX7_RESET_A7_CORE_RESET1]     = { SRC_A7RCR0, BIT(5) },
51         [IMX7_RESET_A7_DBG_RESET0]      = { SRC_A7RCR0, BIT(8) },
52         [IMX7_RESET_A7_DBG_RESET1]      = { SRC_A7RCR0, BIT(9) },
53         [IMX7_RESET_A7_ETM_RESET0]      = { SRC_A7RCR0, BIT(12) },
54         [IMX7_RESET_A7_ETM_RESET1]      = { SRC_A7RCR0, BIT(13) },
55         [IMX7_RESET_A7_SOC_DBG_RESET]   = { SRC_A7RCR0, BIT(20) },
56         [IMX7_RESET_A7_L2RESET]         = { SRC_A7RCR0, BIT(21) },
57         [IMX7_RESET_SW_M4C_RST]         = { SRC_M4RCR, BIT(1) },
58         [IMX7_RESET_SW_M4P_RST]         = { SRC_M4RCR, BIT(2) },
59         [IMX7_RESET_EIM_RST]            = { SRC_ERCR, BIT(0) },
60         [IMX7_RESET_HSICPHY_PORT_RST]   = { SRC_HSICPHY_RCR, BIT(1) },
61         [IMX7_RESET_USBPHY1_POR]        = { SRC_USBOPHY1_RCR, BIT(0) },
62         [IMX7_RESET_USBPHY1_PORT_RST]   = { SRC_USBOPHY1_RCR, BIT(1) },
63         [IMX7_RESET_USBPHY2_POR]        = { SRC_USBOPHY2_RCR, BIT(0) },
64         [IMX7_RESET_USBPHY2_PORT_RST]   = { SRC_USBOPHY2_RCR, BIT(1) },
65         [IMX7_RESET_MIPI_PHY_MRST]      = { SRC_MIPIPHY_RCR, BIT(1) },
66         [IMX7_RESET_MIPI_PHY_SRST]      = { SRC_MIPIPHY_RCR, BIT(2) },
67         [IMX7_RESET_PCIEPHY]            = { SRC_PCIEPHY_RCR, BIT(2) | BIT(1) },
68         [IMX7_RESET_PCIEPHY_PERST]      = { SRC_PCIEPHY_RCR, BIT(3) },
69         [IMX7_RESET_PCIE_CTRL_APPS_EN]  = { SRC_PCIEPHY_RCR, BIT(6) },
70         [IMX7_RESET_DDRC_PRST]          = { SRC_DDRC_RCR, BIT(0) },
71         [IMX7_RESET_DDRC_CORE_RST]      = { SRC_DDRC_RCR, BIT(1) },
72 };
73
74 static struct imx7_src *to_imx7_src(struct reset_controller_dev *rcdev)
75 {
76         return container_of(rcdev, struct imx7_src, rcdev);
77 }
78
79 static int imx7_reset_set(struct reset_controller_dev *rcdev,
80                           unsigned long id, bool assert)
81 {
82         struct imx7_src *imx7src = to_imx7_src(rcdev);
83         const struct imx7_src_signal *signal = &imx7_src_signals[id];
84         unsigned int value = assert ? signal->bit : 0;
85
86         switch (id) {
87         case IMX7_RESET_PCIEPHY:
88                 /*
89                  * wait for more than 10us to release phy g_rst and
90                  * btnrst
91                  */
92                 if (!assert)
93                         udelay(10);
94                 break;
95
96         case IMX7_RESET_PCIE_CTRL_APPS_EN:
97                 value = (assert) ? 0 : signal->bit;
98                 break;
99         }
100
101         return regmap_update_bits(imx7src->regmap,
102                                   signal->offset, signal->bit, value);
103 }
104
105 static int imx7_reset_assert(struct reset_controller_dev *rcdev,
106                              unsigned long id)
107 {
108         return imx7_reset_set(rcdev, id, true);
109 }
110
111 static int imx7_reset_deassert(struct reset_controller_dev *rcdev,
112                                unsigned long id)
113 {
114         return imx7_reset_set(rcdev, id, false);
115 }
116
117 static const struct reset_control_ops imx7_reset_ops = {
118         .assert         = imx7_reset_assert,
119         .deassert       = imx7_reset_deassert,
120 };
121
122 static int imx7_reset_probe(struct platform_device *pdev)
123 {
124         struct imx7_src *imx7src;
125         struct device *dev = &pdev->dev;
126         struct regmap_config config = { .name = "src" };
127
128         imx7src = devm_kzalloc(dev, sizeof(*imx7src), GFP_KERNEL);
129         if (!imx7src)
130                 return -ENOMEM;
131
132         imx7src->regmap = syscon_node_to_regmap(dev->of_node);
133         if (IS_ERR(imx7src->regmap)) {
134                 dev_err(dev, "Unable to get imx7-src regmap");
135                 return PTR_ERR(imx7src->regmap);
136         }
137         regmap_attach_dev(dev, imx7src->regmap, &config);
138
139         imx7src->rcdev.owner     = THIS_MODULE;
140         imx7src->rcdev.nr_resets = IMX7_RESET_NUM;
141         imx7src->rcdev.ops       = &imx7_reset_ops;
142         imx7src->rcdev.of_node   = dev->of_node;
143
144         return devm_reset_controller_register(dev, &imx7src->rcdev);
145 }
146
147 static const struct of_device_id imx7_reset_dt_ids[] = {
148         { .compatible = "fsl,imx7d-src", },
149         { /* sentinel */ },
150 };
151
152 static struct platform_driver imx7_reset_driver = {
153         .probe  = imx7_reset_probe,
154         .driver = {
155                 .name           = KBUILD_MODNAME,
156                 .of_match_table = imx7_reset_dt_ids,
157         },
158 };
159 builtin_platform_driver(imx7_reset_driver);