xref: /openbmc/u-boot/drivers/gpio/stm32f7_gpio.c (revision 93f33627)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
4  * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
5  */
6 
7 #include <common.h>
8 #include <clk.h>
9 #include <dm.h>
10 #include <fdtdec.h>
11 #include <asm/arch/gpio.h>
12 #include <asm/arch/stm32.h>
13 #include <asm/gpio.h>
14 #include <asm/io.h>
15 #include <linux/errno.h>
16 #include <linux/io.h>
17 
18 #define STM32_GPIOS_PER_BANK		16
19 #define MODE_BITS(gpio_pin)		(gpio_pin * 2)
20 #define MODE_BITS_MASK			3
21 #define BSRR_BIT(gpio_pin, value)	BIT(gpio_pin + (value ? 0 : 16))
22 
23 static int stm32_gpio_direction_input(struct udevice *dev, unsigned offset)
24 {
25 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
26 	struct stm32_gpio_regs *regs = priv->regs;
27 	int bits_index = MODE_BITS(offset);
28 	int mask = MODE_BITS_MASK << bits_index;
29 
30 	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_IN << bits_index);
31 
32 	return 0;
33 }
34 
35 static int stm32_gpio_direction_output(struct udevice *dev, unsigned offset,
36 				       int value)
37 {
38 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
39 	struct stm32_gpio_regs *regs = priv->regs;
40 	int bits_index = MODE_BITS(offset);
41 	int mask = MODE_BITS_MASK << bits_index;
42 
43 	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_OUT << bits_index);
44 
45 	writel(BSRR_BIT(offset, value), &regs->bsrr);
46 
47 	return 0;
48 }
49 
50 static int stm32_gpio_get_value(struct udevice *dev, unsigned offset)
51 {
52 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
53 	struct stm32_gpio_regs *regs = priv->regs;
54 
55 	return readl(&regs->idr) & BIT(offset) ? 1 : 0;
56 }
57 
58 static int stm32_gpio_set_value(struct udevice *dev, unsigned offset, int value)
59 {
60 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
61 	struct stm32_gpio_regs *regs = priv->regs;
62 
63 	writel(BSRR_BIT(offset, value), &regs->bsrr);
64 
65 	return 0;
66 }
67 
68 static const struct dm_gpio_ops gpio_stm32_ops = {
69 	.direction_input	= stm32_gpio_direction_input,
70 	.direction_output	= stm32_gpio_direction_output,
71 	.get_value		= stm32_gpio_get_value,
72 	.set_value		= stm32_gpio_set_value,
73 };
74 
75 static int gpio_stm32_probe(struct udevice *dev)
76 {
77 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
78 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
79 	fdt_addr_t addr;
80 	const char *name;
81 
82 	addr = dev_read_addr(dev);
83 	if (addr == FDT_ADDR_T_NONE)
84 		return -EINVAL;
85 
86 	priv->regs = (struct stm32_gpio_regs *)addr;
87 	name = dev_read_string(dev, "st,bank-name");
88 	if (!name)
89 		return -EINVAL;
90 	uc_priv->bank_name = name;
91 	uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios",
92 						   STM32_GPIOS_PER_BANK);
93 	debug("%s, addr = 0x%p, bank_name = %s\n", __func__, (u32 *)priv->regs,
94 	      uc_priv->bank_name);
95 
96 #ifdef CONFIG_CLK
97 	struct clk clk;
98 	int ret;
99 	ret = clk_get_by_index(dev, 0, &clk);
100 	if (ret < 0)
101 		return ret;
102 
103 	ret = clk_enable(&clk);
104 
105 	if (ret) {
106 		dev_err(dev, "failed to enable clock\n");
107 		return ret;
108 	}
109 	debug("clock enabled for device %s\n", dev->name);
110 #endif
111 
112 	return 0;
113 }
114 
115 static const struct udevice_id stm32_gpio_ids[] = {
116 	{ .compatible = "st,stm32-gpio" },
117 	{ }
118 };
119 
120 U_BOOT_DRIVER(gpio_stm32) = {
121 	.name	= "gpio_stm32",
122 	.id	= UCLASS_GPIO,
123 	.of_match = stm32_gpio_ids,
124 	.probe	= gpio_stm32_probe,
125 	.ops	= &gpio_stm32_ops,
126 	.flags	= DM_FLAG_PRE_RELOC | DM_UC_FLAG_SEQ_ALIAS,
127 	.priv_auto_alloc_size	= sizeof(struct stm32_gpio_priv),
128 };
129