xref: /openbmc/linux/drivers/mfd/atmel-hlcdc.c (revision 3fc41476)
1 /*
2  * Copyright (C) 2014 Free Electrons
3  * Copyright (C) 2014 Atmel
4  *
5  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/clk.h>
21 #include <linux/iopoll.h>
22 #include <linux/mfd/atmel-hlcdc.h>
23 #include <linux/mfd/core.h>
24 #include <linux/module.h>
25 #include <linux/mod_devicetable.h>
26 #include <linux/platform_device.h>
27 #include <linux/regmap.h>
28 
29 #define ATMEL_HLCDC_REG_MAX		(0x4000 - 0x4)
30 
31 struct atmel_hlcdc_regmap {
32 	void __iomem *regs;
33 };
34 
35 static const struct mfd_cell atmel_hlcdc_cells[] = {
36 	{
37 		.name = "atmel-hlcdc-pwm",
38 		.of_compatible = "atmel,hlcdc-pwm",
39 	},
40 	{
41 		.name = "atmel-hlcdc-dc",
42 		.of_compatible = "atmel,hlcdc-display-controller",
43 	},
44 };
45 
46 static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
47 					unsigned int val)
48 {
49 	struct atmel_hlcdc_regmap *hregmap = context;
50 
51 	if (reg <= ATMEL_HLCDC_DIS) {
52 		u32 status;
53 
54 		readl_poll_timeout_atomic(hregmap->regs + ATMEL_HLCDC_SR,
55 					  status, !(status & ATMEL_HLCDC_SIP),
56 					  1, 100);
57 	}
58 
59 	writel(val, hregmap->regs + reg);
60 
61 	return 0;
62 }
63 
64 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
65 				       unsigned int *val)
66 {
67 	struct atmel_hlcdc_regmap *hregmap = context;
68 
69 	*val = readl(hregmap->regs + reg);
70 
71 	return 0;
72 }
73 
74 static const struct regmap_config atmel_hlcdc_regmap_config = {
75 	.reg_bits = 32,
76 	.val_bits = 32,
77 	.reg_stride = 4,
78 	.max_register = ATMEL_HLCDC_REG_MAX,
79 	.reg_write = regmap_atmel_hlcdc_reg_write,
80 	.reg_read = regmap_atmel_hlcdc_reg_read,
81 	.fast_io = true,
82 };
83 
84 static int atmel_hlcdc_probe(struct platform_device *pdev)
85 {
86 	struct atmel_hlcdc_regmap *hregmap;
87 	struct device *dev = &pdev->dev;
88 	struct atmel_hlcdc *hlcdc;
89 	struct resource *res;
90 
91 	hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
92 	if (!hregmap)
93 		return -ENOMEM;
94 
95 	hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
96 	if (!hlcdc)
97 		return -ENOMEM;
98 
99 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
100 	hregmap->regs = devm_ioremap_resource(dev, res);
101 	if (IS_ERR(hregmap->regs))
102 		return PTR_ERR(hregmap->regs);
103 
104 	hlcdc->irq = platform_get_irq(pdev, 0);
105 	if (hlcdc->irq < 0)
106 		return hlcdc->irq;
107 
108 	hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
109 	if (IS_ERR(hlcdc->periph_clk)) {
110 		dev_err(dev, "failed to get peripheral clock\n");
111 		return PTR_ERR(hlcdc->periph_clk);
112 	}
113 
114 	hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
115 	if (IS_ERR(hlcdc->sys_clk)) {
116 		dev_err(dev, "failed to get system clock\n");
117 		return PTR_ERR(hlcdc->sys_clk);
118 	}
119 
120 	hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
121 	if (IS_ERR(hlcdc->slow_clk)) {
122 		dev_err(dev, "failed to get slow clock\n");
123 		return PTR_ERR(hlcdc->slow_clk);
124 	}
125 
126 	hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
127 					 &atmel_hlcdc_regmap_config);
128 	if (IS_ERR(hlcdc->regmap))
129 		return PTR_ERR(hlcdc->regmap);
130 
131 	dev_set_drvdata(dev, hlcdc);
132 
133 	return devm_mfd_add_devices(dev, -1, atmel_hlcdc_cells,
134 				    ARRAY_SIZE(atmel_hlcdc_cells),
135 				    NULL, 0, NULL);
136 }
137 
138 static const struct of_device_id atmel_hlcdc_match[] = {
139 	{ .compatible = "atmel,at91sam9n12-hlcdc" },
140 	{ .compatible = "atmel,at91sam9x5-hlcdc" },
141 	{ .compatible = "atmel,sama5d2-hlcdc" },
142 	{ .compatible = "atmel,sama5d3-hlcdc" },
143 	{ .compatible = "atmel,sama5d4-hlcdc" },
144 	{ .compatible = "microchip,sam9x60-hlcdc" },
145 	{ /* sentinel */ },
146 };
147 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
148 
149 static struct platform_driver atmel_hlcdc_driver = {
150 	.probe = atmel_hlcdc_probe,
151 	.driver = {
152 		.name = "atmel-hlcdc",
153 		.of_match_table = atmel_hlcdc_match,
154 	},
155 };
156 module_platform_driver(atmel_hlcdc_driver);
157 
158 MODULE_ALIAS("platform:atmel-hlcdc");
159 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
160 MODULE_DESCRIPTION("Atmel HLCDC driver");
161 MODULE_LICENSE("GPL v2");
162