xref: /openbmc/linux/drivers/gpio/gpio-twl6040.c (revision 6dbe6c07)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Access to GPOs on TWL6040 chip
4  *
5  * Copyright (C) 2012 Texas Instruments, Inc.
6  *
7  * Authors:
8  *	Sergio Aguirre <saaguirre@ti.com>
9  *	Peter Ujfalusi <peter.ujfalusi@ti.com>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/kthread.h>
15 #include <linux/irq.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/platform_device.h>
18 #include <linux/bitops.h>
19 #include <linux/of.h>
20 
21 #include <linux/mfd/twl6040.h>
22 
twl6040gpo_get(struct gpio_chip * chip,unsigned offset)23 static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
24 {
25 	struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
26 	int ret = 0;
27 
28 	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
29 	if (ret < 0)
30 		return ret;
31 
32 	return !!(ret & BIT(offset));
33 }
34 
twl6040gpo_get_direction(struct gpio_chip * chip,unsigned offset)35 static int twl6040gpo_get_direction(struct gpio_chip *chip, unsigned offset)
36 {
37 	return GPIO_LINE_DIRECTION_OUT;
38 }
39 
twl6040gpo_direction_out(struct gpio_chip * chip,unsigned offset,int value)40 static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
41 				    int value)
42 {
43 	/* This only drives GPOs, and can't change direction */
44 	return 0;
45 }
46 
twl6040gpo_set(struct gpio_chip * chip,unsigned offset,int value)47 static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
48 {
49 	struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
50 	int ret;
51 	u8 gpoctl;
52 
53 	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
54 	if (ret < 0)
55 		return;
56 
57 	if (value)
58 		gpoctl = ret | BIT(offset);
59 	else
60 		gpoctl = ret & ~BIT(offset);
61 
62 	twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
63 }
64 
65 static struct gpio_chip twl6040gpo_chip = {
66 	.label			= "twl6040",
67 	.owner			= THIS_MODULE,
68 	.get			= twl6040gpo_get,
69 	.direction_output	= twl6040gpo_direction_out,
70 	.get_direction		= twl6040gpo_get_direction,
71 	.set			= twl6040gpo_set,
72 	.can_sleep		= true,
73 };
74 
75 /*----------------------------------------------------------------------*/
76 
gpo_twl6040_probe(struct platform_device * pdev)77 static int gpo_twl6040_probe(struct platform_device *pdev)
78 {
79 	struct device *twl6040_core_dev = pdev->dev.parent;
80 	struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
81 	int ret;
82 
83 	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
84 
85 	twl6040gpo_chip.base = -1;
86 
87 	if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
88 		twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
89 	else
90 		twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
91 
92 	twl6040gpo_chip.parent = &pdev->dev;
93 
94 	ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
95 	if (ret < 0) {
96 		dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
97 		twl6040gpo_chip.ngpio = 0;
98 	}
99 
100 	return ret;
101 }
102 
103 /* Note:  this hardware lives inside an I2C-based multi-function device. */
104 MODULE_ALIAS("platform:twl6040-gpo");
105 
106 static struct platform_driver gpo_twl6040_driver = {
107 	.driver = {
108 		.name	= "twl6040-gpo",
109 	},
110 	.probe		= gpo_twl6040_probe,
111 };
112 
113 module_platform_driver(gpo_twl6040_driver);
114 
115 MODULE_AUTHOR("Texas Instruments, Inc.");
116 MODULE_DESCRIPTION("GPO interface for TWL6040");
117 MODULE_LICENSE("GPL");
118