xref: /openbmc/u-boot/drivers/gpio/gpio-rcar.c (revision 7fd65ef5)
1 /*
2  * Copyright (C) 2017 Marek Vasut <marek.vasut@gmail.com>
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <clk.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <asm/gpio.h>
12 #include <asm/io.h>
13 #include "../pinctrl/renesas/sh_pfc.h"
14 
15 #define GPIO_IOINTSEL	0x00	/* General IO/Interrupt Switching Register */
16 #define GPIO_INOUTSEL	0x04	/* General Input/Output Switching Register */
17 #define GPIO_OUTDT	0x08	/* General Output Register */
18 #define GPIO_INDT	0x0c	/* General Input Register */
19 #define GPIO_INTDT	0x10	/* Interrupt Display Register */
20 #define GPIO_INTCLR	0x14	/* Interrupt Clear Register */
21 #define GPIO_INTMSK	0x18	/* Interrupt Mask Register */
22 #define GPIO_MSKCLR	0x1c	/* Interrupt Mask Clear Register */
23 #define GPIO_POSNEG	0x20	/* Positive/Negative Logic Select Register */
24 #define GPIO_EDGLEVEL	0x24	/* Edge/level Select Register */
25 #define GPIO_FILONOFF	0x28	/* Chattering Prevention On/Off Register */
26 #define GPIO_BOTHEDGE	0x4c	/* One Edge/Both Edge Select Register */
27 
28 #define RCAR_MAX_GPIO_PER_BANK		32
29 
30 DECLARE_GLOBAL_DATA_PTR;
31 
32 struct rcar_gpio_priv {
33 	void __iomem		*regs;
34 	int			pfc_offset;
35 };
36 
37 static int rcar_gpio_get_value(struct udevice *dev, unsigned offset)
38 {
39 	struct rcar_gpio_priv *priv = dev_get_priv(dev);
40 	const u32 bit = BIT(offset);
41 
42 	/*
43 	 * Testing on r8a7790 shows that INDT does not show correct pin state
44 	 * when configured as output, so use OUTDT in case of output pins.
45 	 */
46 	if (readl(priv->regs + GPIO_INOUTSEL) & bit)
47 		return !!(readl(priv->regs + GPIO_OUTDT) & bit);
48 	else
49 		return !!(readl(priv->regs + GPIO_INDT) & bit);
50 }
51 
52 static int rcar_gpio_set_value(struct udevice *dev, unsigned offset,
53 			       int value)
54 {
55 	struct rcar_gpio_priv *priv = dev_get_priv(dev);
56 
57 	if (value)
58 		setbits_le32(priv->regs + GPIO_OUTDT, BIT(offset));
59 	else
60 		clrbits_le32(priv->regs + GPIO_OUTDT, BIT(offset));
61 
62 	return 0;
63 }
64 
65 static void rcar_gpio_set_direction(void __iomem *regs, unsigned offset,
66 				    bool output)
67 {
68 	/*
69 	 * follow steps in the GPIO documentation for
70 	 * "Setting General Output Mode" and
71 	 * "Setting General Input Mode"
72 	 */
73 
74 	/* Configure postive logic in POSNEG */
75 	clrbits_le32(regs + GPIO_POSNEG, BIT(offset));
76 
77 	/* Select "General Input/Output Mode" in IOINTSEL */
78 	clrbits_le32(regs + GPIO_IOINTSEL, BIT(offset));
79 
80 	/* Select Input Mode or Output Mode in INOUTSEL */
81 	if (output)
82 		setbits_le32(regs + GPIO_INOUTSEL, BIT(offset));
83 	else
84 		clrbits_le32(regs + GPIO_INOUTSEL, BIT(offset));
85 }
86 
87 static int rcar_gpio_direction_input(struct udevice *dev, unsigned offset)
88 {
89 	struct rcar_gpio_priv *priv = dev_get_priv(dev);
90 
91 	rcar_gpio_set_direction(priv->regs, offset, false);
92 
93 	return 0;
94 }
95 
96 static int rcar_gpio_direction_output(struct udevice *dev, unsigned offset,
97 				      int value)
98 {
99 	struct rcar_gpio_priv *priv = dev_get_priv(dev);
100 
101 	/* write GPIO value to output before selecting output mode of pin */
102 	rcar_gpio_set_value(dev, offset, value);
103 	rcar_gpio_set_direction(priv->regs, offset, true);
104 
105 	return 0;
106 }
107 
108 static int rcar_gpio_get_function(struct udevice *dev, unsigned offset)
109 {
110 	struct rcar_gpio_priv *priv = dev_get_priv(dev);
111 
112 	if (readl(priv->regs + GPIO_INOUTSEL) & BIT(offset))
113 		return GPIOF_OUTPUT;
114 	else
115 		return GPIOF_INPUT;
116 }
117 
118 static int rcar_gpio_request(struct udevice *dev, unsigned offset,
119 			     const char *label)
120 {
121 	struct rcar_gpio_priv *priv = dev_get_priv(dev);
122 	struct udevice *pctldev;
123 	int ret;
124 
125 	ret = uclass_get_device(UCLASS_PINCTRL, 0, &pctldev);
126 	if (ret)
127 		return ret;
128 
129 	return sh_pfc_config_mux_for_gpio(pctldev, priv->pfc_offset + offset);
130 }
131 
132 static const struct dm_gpio_ops rcar_gpio_ops = {
133 	.request		= rcar_gpio_request,
134 	.direction_input	= rcar_gpio_direction_input,
135 	.direction_output	= rcar_gpio_direction_output,
136 	.get_value		= rcar_gpio_get_value,
137 	.set_value		= rcar_gpio_set_value,
138 	.get_function		= rcar_gpio_get_function,
139 };
140 
141 static int rcar_gpio_probe(struct udevice *dev)
142 {
143 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
144 	struct rcar_gpio_priv *priv = dev_get_priv(dev);
145 	struct fdtdec_phandle_args args;
146 	struct clk clk;
147 	int node = dev_of_offset(dev);
148 	int ret;
149 
150 	priv->regs = (void __iomem *)devfdt_get_addr(dev);
151 	uc_priv->bank_name = dev->name;
152 
153 	ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, node, "gpio-ranges",
154 					     NULL, 3, 0, &args);
155 	priv->pfc_offset = ret == 0 ? args.args[1] : -1;
156 	uc_priv->gpio_count = ret == 0 ? args.args[2] : RCAR_MAX_GPIO_PER_BANK;
157 
158 	ret = clk_get_by_index(dev, 0, &clk);
159 	if (ret < 0) {
160 		dev_err(dev, "Failed to get GPIO bank clock\n");
161 		return ret;
162 	}
163 
164 	ret = clk_enable(&clk);
165 	clk_free(&clk);
166 	if (ret) {
167 		dev_err(dev, "Failed to enable GPIO bank clock\n");
168 		return ret;
169 	}
170 
171 	return 0;
172 }
173 
174 static const struct udevice_id rcar_gpio_ids[] = {
175 	{ .compatible = "renesas,gpio-r8a7795" },
176 	{ .compatible = "renesas,gpio-r8a7796" },
177 	{ .compatible = "renesas,gpio-r8a77970" },
178 	{ .compatible = "renesas,gpio-r8a77995" },
179 	{ .compatible = "renesas,rcar-gen3-gpio" },
180 	{ /* sentinel */ }
181 };
182 
183 U_BOOT_DRIVER(rcar_gpio) = {
184 	.name	= "rcar-gpio",
185 	.id	= UCLASS_GPIO,
186 	.of_match = rcar_gpio_ids,
187 	.ops	= &rcar_gpio_ops,
188 	.priv_auto_alloc_size = sizeof(struct rcar_gpio_priv),
189 	.probe	= rcar_gpio_probe,
190 };
191