xref: /openbmc/linux/drivers/mfd/atmel-hlcdc.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 Free Electrons
4  * Copyright (C) 2014 Atmel
5  *
6  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/iopoll.h>
11 #include <linux/mfd/atmel-hlcdc.h>
12 #include <linux/mfd/core.h>
13 #include <linux/module.h>
14 #include <linux/mod_devicetable.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 
18 #define ATMEL_HLCDC_REG_MAX		(0x4000 - 0x4)
19 
20 struct atmel_hlcdc_regmap {
21 	void __iomem *regs;
22 	struct device *dev;
23 };
24 
25 static const struct mfd_cell atmel_hlcdc_cells[] = {
26 	{
27 		.name = "atmel-hlcdc-pwm",
28 		.of_compatible = "atmel,hlcdc-pwm",
29 	},
30 	{
31 		.name = "atmel-hlcdc-dc",
32 		.of_compatible = "atmel,hlcdc-display-controller",
33 	},
34 };
35 
36 static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
37 					unsigned int val)
38 {
39 	struct atmel_hlcdc_regmap *hregmap = context;
40 
41 	if (reg <= ATMEL_HLCDC_DIS) {
42 		u32 status;
43 		int ret;
44 
45 		ret = readl_poll_timeout_atomic(hregmap->regs + ATMEL_HLCDC_SR,
46 						status,
47 						!(status & ATMEL_HLCDC_SIP),
48 						1, 100);
49 		if (ret) {
50 			dev_err(hregmap->dev,
51 				"Timeout! Clock domain synchronization is in progress!\n");
52 			return ret;
53 		}
54 	}
55 
56 	writel(val, hregmap->regs + reg);
57 
58 	return 0;
59 }
60 
61 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
62 				       unsigned int *val)
63 {
64 	struct atmel_hlcdc_regmap *hregmap = context;
65 
66 	*val = readl(hregmap->regs + reg);
67 
68 	return 0;
69 }
70 
71 static const struct regmap_config atmel_hlcdc_regmap_config = {
72 	.reg_bits = 32,
73 	.val_bits = 32,
74 	.reg_stride = 4,
75 	.max_register = ATMEL_HLCDC_REG_MAX,
76 	.reg_write = regmap_atmel_hlcdc_reg_write,
77 	.reg_read = regmap_atmel_hlcdc_reg_read,
78 	.fast_io = true,
79 };
80 
81 static int atmel_hlcdc_probe(struct platform_device *pdev)
82 {
83 	struct atmel_hlcdc_regmap *hregmap;
84 	struct device *dev = &pdev->dev;
85 	struct atmel_hlcdc *hlcdc;
86 	struct resource *res;
87 
88 	hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
89 	if (!hregmap)
90 		return -ENOMEM;
91 
92 	hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
93 	if (!hlcdc)
94 		return -ENOMEM;
95 
96 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
97 	hregmap->regs = devm_ioremap_resource(dev, res);
98 	if (IS_ERR(hregmap->regs))
99 		return PTR_ERR(hregmap->regs);
100 
101 	hregmap->dev = &pdev->dev;
102 
103 	hlcdc->irq = platform_get_irq(pdev, 0);
104 	if (hlcdc->irq < 0)
105 		return hlcdc->irq;
106 
107 	hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
108 	if (IS_ERR(hlcdc->periph_clk)) {
109 		dev_err(dev, "failed to get peripheral clock\n");
110 		return PTR_ERR(hlcdc->periph_clk);
111 	}
112 
113 	hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
114 	if (IS_ERR(hlcdc->sys_clk)) {
115 		dev_err(dev, "failed to get system clock\n");
116 		return PTR_ERR(hlcdc->sys_clk);
117 	}
118 
119 	hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
120 	if (IS_ERR(hlcdc->slow_clk)) {
121 		dev_err(dev, "failed to get slow clock\n");
122 		return PTR_ERR(hlcdc->slow_clk);
123 	}
124 
125 	hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
126 					 &atmel_hlcdc_regmap_config);
127 	if (IS_ERR(hlcdc->regmap))
128 		return PTR_ERR(hlcdc->regmap);
129 
130 	dev_set_drvdata(dev, hlcdc);
131 
132 	return devm_mfd_add_devices(dev, -1, atmel_hlcdc_cells,
133 				    ARRAY_SIZE(atmel_hlcdc_cells),
134 				    NULL, 0, NULL);
135 }
136 
137 static const struct of_device_id atmel_hlcdc_match[] = {
138 	{ .compatible = "atmel,at91sam9n12-hlcdc" },
139 	{ .compatible = "atmel,at91sam9x5-hlcdc" },
140 	{ .compatible = "atmel,sama5d2-hlcdc" },
141 	{ .compatible = "atmel,sama5d3-hlcdc" },
142 	{ .compatible = "atmel,sama5d4-hlcdc" },
143 	{ .compatible = "microchip,sam9x60-hlcdc" },
144 	{ /* sentinel */ },
145 };
146 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
147 
148 static struct platform_driver atmel_hlcdc_driver = {
149 	.probe = atmel_hlcdc_probe,
150 	.driver = {
151 		.name = "atmel-hlcdc",
152 		.of_match_table = atmel_hlcdc_match,
153 	},
154 };
155 module_platform_driver(atmel_hlcdc_driver);
156 
157 MODULE_ALIAS("platform:atmel-hlcdc");
158 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
159 MODULE_DESCRIPTION("Atmel HLCDC driver");
160 MODULE_LICENSE("GPL v2");
161