xref: /linux/drivers/mfd/atmel-hlcdc.c (revision f85f5ae45ad945270a8884261de8249431e8b5a6)
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 
87 	hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
88 	if (!hregmap)
89 		return -ENOMEM;
90 
91 	hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
92 	if (!hlcdc)
93 		return -ENOMEM;
94 
95 	hregmap->regs = devm_platform_ioremap_resource(pdev, 0);
96 	if (IS_ERR(hregmap->regs))
97 		return PTR_ERR(hregmap->regs);
98 
99 	hregmap->dev = &pdev->dev;
100 
101 	hlcdc->irq = platform_get_irq(pdev, 0);
102 	if (hlcdc->irq < 0)
103 		return hlcdc->irq;
104 
105 	hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
106 	if (IS_ERR(hlcdc->periph_clk)) {
107 		dev_err(dev, "failed to get peripheral clock\n");
108 		return PTR_ERR(hlcdc->periph_clk);
109 	}
110 
111 	hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
112 	if (IS_ERR(hlcdc->sys_clk)) {
113 		dev_err(dev, "failed to get system clock\n");
114 		return PTR_ERR(hlcdc->sys_clk);
115 	}
116 
117 	hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
118 	if (IS_ERR(hlcdc->slow_clk)) {
119 		dev_err(dev, "failed to get slow clock\n");
120 		return PTR_ERR(hlcdc->slow_clk);
121 	}
122 
123 	hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
124 					 &atmel_hlcdc_regmap_config);
125 	if (IS_ERR(hlcdc->regmap))
126 		return PTR_ERR(hlcdc->regmap);
127 
128 	dev_set_drvdata(dev, hlcdc);
129 
130 	return devm_mfd_add_devices(dev, -1, atmel_hlcdc_cells,
131 				    ARRAY_SIZE(atmel_hlcdc_cells),
132 				    NULL, 0, NULL);
133 }
134 
135 static const struct of_device_id atmel_hlcdc_match[] = {
136 	{ .compatible = "atmel,at91sam9n12-hlcdc" },
137 	{ .compatible = "atmel,at91sam9x5-hlcdc" },
138 	{ .compatible = "atmel,sama5d2-hlcdc" },
139 	{ .compatible = "atmel,sama5d3-hlcdc" },
140 	{ .compatible = "atmel,sama5d4-hlcdc" },
141 	{ .compatible = "microchip,sam9x60-hlcdc" },
142 	{ /* sentinel */ },
143 };
144 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
145 
146 static struct platform_driver atmel_hlcdc_driver = {
147 	.probe = atmel_hlcdc_probe,
148 	.driver = {
149 		.name = "atmel-hlcdc",
150 		.of_match_table = atmel_hlcdc_match,
151 	},
152 };
153 module_platform_driver(atmel_hlcdc_driver);
154 
155 MODULE_ALIAS("platform:atmel-hlcdc");
156 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
157 MODULE_DESCRIPTION("Atmel HLCDC driver");
158 MODULE_LICENSE("GPL v2");
159