xref: /openbmc/u-boot/drivers/gpio/stm32f7_gpio.c (revision 203e94f6)
1 /*
2  * (C) Copyright 2017
3  * Vikas Manocha, <vikas.manocha@st.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <clk.h>
10 #include <dm.h>
11 #include <fdtdec.h>
12 #include <asm/arch/gpio.h>
13 #include <asm/arch/stm32.h>
14 #include <asm/gpio.h>
15 #include <asm/io.h>
16 #include <linux/errno.h>
17 #include <linux/io.h>
18 
19 #define MAX_SIZE_BANK_NAME		5
20 #define STM32_GPIOS_PER_BANK		16
21 #define MODE_BITS(gpio_pin)		(gpio_pin * 2)
22 #define MODE_BITS_MASK			3
23 #define IN_OUT_BIT_INDEX(gpio_pin)	(1UL << (gpio_pin))
24 
25 DECLARE_GLOBAL_DATA_PTR;
26 
27 static int stm32_gpio_direction_input(struct udevice *dev, unsigned offset)
28 {
29 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
30 	struct stm32_gpio_regs *regs = priv->regs;
31 	int bits_index = MODE_BITS(offset);
32 	int mask = MODE_BITS_MASK << bits_index;
33 
34 	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_IN << bits_index);
35 
36 	return 0;
37 }
38 
39 static int stm32_gpio_direction_output(struct udevice *dev, unsigned offset,
40 				       int value)
41 {
42 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
43 	struct stm32_gpio_regs *regs = priv->regs;
44 	int bits_index = MODE_BITS(offset);
45 	int mask = MODE_BITS_MASK << bits_index;
46 
47 	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_OUT << bits_index);
48 	mask = IN_OUT_BIT_INDEX(offset);
49 	clrsetbits_le32(&regs->odr, mask, value ? mask : 0);
50 
51 	return 0;
52 }
53 
54 static int stm32_gpio_get_value(struct udevice *dev, unsigned offset)
55 {
56 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
57 	struct stm32_gpio_regs *regs = priv->regs;
58 
59 	return readl(&regs->idr) & IN_OUT_BIT_INDEX(offset) ? 1 : 0;
60 }
61 
62 static int stm32_gpio_set_value(struct udevice *dev, unsigned offset, int value)
63 {
64 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
65 	struct stm32_gpio_regs *regs = priv->regs;
66 	int mask = IN_OUT_BIT_INDEX(offset);
67 
68 	clrsetbits_le32(&regs->odr, mask, value ? mask : 0);
69 
70 	return 0;
71 }
72 
73 static const struct dm_gpio_ops gpio_stm32_ops = {
74 	.direction_input	= stm32_gpio_direction_input,
75 	.direction_output	= stm32_gpio_direction_output,
76 	.get_value		= stm32_gpio_get_value,
77 	.set_value		= stm32_gpio_set_value,
78 };
79 
80 static int gpio_stm32_probe(struct udevice *dev)
81 {
82 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
83 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
84 	fdt_addr_t addr;
85 	char *name;
86 
87 	addr = devfdt_get_addr(dev);
88 	if (addr == FDT_ADDR_T_NONE)
89 		return -EINVAL;
90 
91 	priv->regs = (struct stm32_gpio_regs *)addr;
92 	name = (char *)fdtdec_locate_byte_array(gd->fdt_blob,
93 						dev_of_offset(dev),
94 						"st,bank-name",
95 						MAX_SIZE_BANK_NAME);
96 	if (!name)
97 		return -EINVAL;
98 	uc_priv->bank_name = name;
99 	uc_priv->gpio_count = STM32_GPIOS_PER_BANK;
100 	debug("%s, addr = 0x%p, bank_name = %s\n", __func__, (u32 *)priv->regs,
101 	      uc_priv->bank_name);
102 
103 #ifdef CONFIG_CLK
104 	struct clk clk;
105 	int ret;
106 	ret = clk_get_by_index(dev, 0, &clk);
107 	if (ret < 0)
108 		return ret;
109 
110 	ret = clk_enable(&clk);
111 
112 	if (ret) {
113 		dev_err(dev, "failed to enable clock\n");
114 		return ret;
115 	}
116 	debug("clock enabled for device %s\n", dev->name);
117 #endif
118 
119 	return 0;
120 }
121 
122 static const struct udevice_id stm32_gpio_ids[] = {
123 	{ .compatible = "st,stm32-gpio" },
124 	{ }
125 };
126 
127 U_BOOT_DRIVER(gpio_stm32) = {
128 	.name	= "gpio_stm32",
129 	.id	= UCLASS_GPIO,
130 	.of_match = stm32_gpio_ids,
131 	.probe	= gpio_stm32_probe,
132 	.ops	= &gpio_stm32_ops,
133 	.flags	= DM_FLAG_PRE_RELOC | DM_UC_FLAG_SEQ_ALIAS,
134 	.priv_auto_alloc_size	= sizeof(struct stm32_gpio_priv),
135 };
136