xref: /openbmc/linux/drivers/mfd/atmel-hlcdc.c (revision 9cfc5c90)
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/platform_device.h>
26 #include <linux/regmap.h>
27 
28 #define ATMEL_HLCDC_REG_MAX		(0x4000 - 0x4)
29 
30 struct atmel_hlcdc_regmap {
31 	void __iomem *regs;
32 };
33 
34 static const struct mfd_cell atmel_hlcdc_cells[] = {
35 	{
36 		.name = "atmel-hlcdc-pwm",
37 		.of_compatible = "atmel,hlcdc-pwm",
38 	},
39 	{
40 		.name = "atmel-hlcdc-dc",
41 		.of_compatible = "atmel,hlcdc-display-controller",
42 	},
43 };
44 
45 static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
46 					unsigned int val)
47 {
48 	struct atmel_hlcdc_regmap *hregmap = context;
49 
50 	if (reg <= ATMEL_HLCDC_DIS) {
51 		u32 status;
52 
53 		readl_poll_timeout(hregmap->regs + ATMEL_HLCDC_SR, status,
54 				   !(status & ATMEL_HLCDC_SIP), 1, 100);
55 	}
56 
57 	writel(val, hregmap->regs + reg);
58 
59 	return 0;
60 }
61 
62 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
63 				       unsigned int *val)
64 {
65 	struct atmel_hlcdc_regmap *hregmap = context;
66 
67 	*val = readl(hregmap->regs + reg);
68 
69 	return 0;
70 }
71 
72 static const struct regmap_config atmel_hlcdc_regmap_config = {
73 	.reg_bits = 32,
74 	.val_bits = 32,
75 	.reg_stride = 4,
76 	.max_register = ATMEL_HLCDC_REG_MAX,
77 	.reg_write = regmap_atmel_hlcdc_reg_write,
78 	.reg_read = regmap_atmel_hlcdc_reg_read,
79 	.fast_io = true,
80 };
81 
82 static int atmel_hlcdc_probe(struct platform_device *pdev)
83 {
84 	struct atmel_hlcdc_regmap *hregmap;
85 	struct device *dev = &pdev->dev;
86 	struct atmel_hlcdc *hlcdc;
87 	struct resource *res;
88 
89 	hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
90 	if (!hregmap)
91 		return -ENOMEM;
92 
93 	hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
94 	if (!hlcdc)
95 		return -ENOMEM;
96 
97 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
98 	hregmap->regs = devm_ioremap_resource(dev, res);
99 	if (IS_ERR(hregmap->regs))
100 		return PTR_ERR(hregmap->regs);
101 
102 	hlcdc->irq = platform_get_irq(pdev, 0);
103 	if (hlcdc->irq < 0)
104 		return hlcdc->irq;
105 
106 	hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
107 	if (IS_ERR(hlcdc->periph_clk)) {
108 		dev_err(dev, "failed to get peripheral clock\n");
109 		return PTR_ERR(hlcdc->periph_clk);
110 	}
111 
112 	hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
113 	if (IS_ERR(hlcdc->sys_clk)) {
114 		dev_err(dev, "failed to get system clock\n");
115 		return PTR_ERR(hlcdc->sys_clk);
116 	}
117 
118 	hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
119 	if (IS_ERR(hlcdc->slow_clk)) {
120 		dev_err(dev, "failed to get slow clock\n");
121 		return PTR_ERR(hlcdc->slow_clk);
122 	}
123 
124 	hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
125 					 &atmel_hlcdc_regmap_config);
126 	if (IS_ERR(hlcdc->regmap))
127 		return PTR_ERR(hlcdc->regmap);
128 
129 	dev_set_drvdata(dev, hlcdc);
130 
131 	return mfd_add_devices(dev, -1, atmel_hlcdc_cells,
132 			       ARRAY_SIZE(atmel_hlcdc_cells),
133 			       NULL, 0, NULL);
134 }
135 
136 static int atmel_hlcdc_remove(struct platform_device *pdev)
137 {
138 	mfd_remove_devices(&pdev->dev);
139 
140 	return 0;
141 }
142 
143 static const struct of_device_id atmel_hlcdc_match[] = {
144 	{ .compatible = "atmel,at91sam9n12-hlcdc" },
145 	{ .compatible = "atmel,at91sam9x5-hlcdc" },
146 	{ .compatible = "atmel,sama5d2-hlcdc" },
147 	{ .compatible = "atmel,sama5d3-hlcdc" },
148 	{ .compatible = "atmel,sama5d4-hlcdc" },
149 	{ /* sentinel */ },
150 };
151 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
152 
153 static struct platform_driver atmel_hlcdc_driver = {
154 	.probe = atmel_hlcdc_probe,
155 	.remove = atmel_hlcdc_remove,
156 	.driver = {
157 		.name = "atmel-hlcdc",
158 		.of_match_table = atmel_hlcdc_match,
159 	},
160 };
161 module_platform_driver(atmel_hlcdc_driver);
162 
163 MODULE_ALIAS("platform:atmel-hlcdc");
164 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
165 MODULE_DESCRIPTION("Atmel HLCDC driver");
166 MODULE_LICENSE("GPL v2");
167