xref: /openbmc/u-boot/drivers/gpio/stm32f7_gpio.c (revision 8f240a3b)
1 /*
2  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
3  * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
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 STM32_GPIOS_PER_BANK		16
20 #define MODE_BITS(gpio_pin)		(gpio_pin * 2)
21 #define MODE_BITS_MASK			3
22 #define IN_OUT_BIT_INDEX(gpio_pin)	(1UL << (gpio_pin))
23 
24 static int stm32_gpio_direction_input(struct udevice *dev, unsigned offset)
25 {
26 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
27 	struct stm32_gpio_regs *regs = priv->regs;
28 	int bits_index = MODE_BITS(offset);
29 	int mask = MODE_BITS_MASK << bits_index;
30 
31 	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_IN << bits_index);
32 
33 	return 0;
34 }
35 
36 static int stm32_gpio_direction_output(struct udevice *dev, unsigned offset,
37 				       int value)
38 {
39 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
40 	struct stm32_gpio_regs *regs = priv->regs;
41 	int bits_index = MODE_BITS(offset);
42 	int mask = MODE_BITS_MASK << bits_index;
43 
44 	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_OUT << bits_index);
45 	mask = IN_OUT_BIT_INDEX(offset);
46 	clrsetbits_le32(&regs->odr, mask, value ? mask : 0);
47 
48 	return 0;
49 }
50 
51 static int stm32_gpio_get_value(struct udevice *dev, unsigned offset)
52 {
53 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
54 	struct stm32_gpio_regs *regs = priv->regs;
55 
56 	return readl(&regs->idr) & IN_OUT_BIT_INDEX(offset) ? 1 : 0;
57 }
58 
59 static int stm32_gpio_set_value(struct udevice *dev, unsigned offset, int value)
60 {
61 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
62 	struct stm32_gpio_regs *regs = priv->regs;
63 	int mask = IN_OUT_BIT_INDEX(offset);
64 
65 	clrsetbits_le32(&regs->odr, mask, value ? mask : 0);
66 
67 	return 0;
68 }
69 
70 static const struct dm_gpio_ops gpio_stm32_ops = {
71 	.direction_input	= stm32_gpio_direction_input,
72 	.direction_output	= stm32_gpio_direction_output,
73 	.get_value		= stm32_gpio_get_value,
74 	.set_value		= stm32_gpio_set_value,
75 };
76 
77 static int gpio_stm32_probe(struct udevice *dev)
78 {
79 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
80 	struct stm32_gpio_priv *priv = dev_get_priv(dev);
81 	fdt_addr_t addr;
82 	const char *name;
83 
84 	addr = dev_read_addr(dev);
85 	if (addr == FDT_ADDR_T_NONE)
86 		return -EINVAL;
87 
88 	priv->regs = (struct stm32_gpio_regs *)addr;
89 	name = dev_read_string(dev, "st,bank-name");
90 	if (!name)
91 		return -EINVAL;
92 	uc_priv->bank_name = name;
93 	uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios",
94 						   STM32_GPIOS_PER_BANK);
95 	debug("%s, addr = 0x%p, bank_name = %s\n", __func__, (u32 *)priv->regs,
96 	      uc_priv->bank_name);
97 
98 #ifdef CONFIG_CLK
99 	struct clk clk;
100 	int ret;
101 	ret = clk_get_by_index(dev, 0, &clk);
102 	if (ret < 0)
103 		return ret;
104 
105 	ret = clk_enable(&clk);
106 
107 	if (ret) {
108 		dev_err(dev, "failed to enable clock\n");
109 		return ret;
110 	}
111 	debug("clock enabled for device %s\n", dev->name);
112 #endif
113 
114 	return 0;
115 }
116 
117 static const struct udevice_id stm32_gpio_ids[] = {
118 	{ .compatible = "st,stm32-gpio" },
119 	{ }
120 };
121 
122 U_BOOT_DRIVER(gpio_stm32) = {
123 	.name	= "gpio_stm32",
124 	.id	= UCLASS_GPIO,
125 	.of_match = stm32_gpio_ids,
126 	.probe	= gpio_stm32_probe,
127 	.ops	= &gpio_stm32_ops,
128 	.flags	= DM_FLAG_PRE_RELOC | DM_UC_FLAG_SEQ_ALIAS,
129 	.priv_auto_alloc_size	= sizeof(struct stm32_gpio_priv),
130 };
131