1*703b288fSMatti Vaittinen // SPDX-License-Identifier: GPL-2.0
2*703b288fSMatti Vaittinen /*
3*703b288fSMatti Vaittinen * Support to GPOs on ROHM BD71815
4*703b288fSMatti Vaittinen * Copyright 2021 ROHM Semiconductors.
5*703b288fSMatti Vaittinen * Author: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
6*703b288fSMatti Vaittinen *
7*703b288fSMatti Vaittinen * Copyright 2014 Embest Technology Co. Ltd. Inc.
8*703b288fSMatti Vaittinen * Author: yanglsh@embest-tech.com
9*703b288fSMatti Vaittinen */
10*703b288fSMatti Vaittinen
11*703b288fSMatti Vaittinen #include <linux/gpio/driver.h>
12*703b288fSMatti Vaittinen #include <linux/init.h>
13*703b288fSMatti Vaittinen #include <linux/irq.h>
14*703b288fSMatti Vaittinen #include <linux/module.h>
15*703b288fSMatti Vaittinen #include <linux/of.h>
16*703b288fSMatti Vaittinen #include <linux/platform_device.h>
17*703b288fSMatti Vaittinen /* For the BD71815 register definitions */
18*703b288fSMatti Vaittinen #include <linux/mfd/rohm-bd71815.h>
19*703b288fSMatti Vaittinen
20*703b288fSMatti Vaittinen struct bd71815_gpio {
21*703b288fSMatti Vaittinen /* chip.parent points the MFD which provides DT node and regmap */
22*703b288fSMatti Vaittinen struct gpio_chip chip;
23*703b288fSMatti Vaittinen /* dev points to the platform device for devm and prints */
24*703b288fSMatti Vaittinen struct device *dev;
25*703b288fSMatti Vaittinen struct regmap *regmap;
26*703b288fSMatti Vaittinen };
27*703b288fSMatti Vaittinen
bd71815gpo_get(struct gpio_chip * chip,unsigned int offset)28*703b288fSMatti Vaittinen static int bd71815gpo_get(struct gpio_chip *chip, unsigned int offset)
29*703b288fSMatti Vaittinen {
30*703b288fSMatti Vaittinen struct bd71815_gpio *bd71815 = gpiochip_get_data(chip);
31*703b288fSMatti Vaittinen int ret, val;
32*703b288fSMatti Vaittinen
33*703b288fSMatti Vaittinen ret = regmap_read(bd71815->regmap, BD71815_REG_GPO, &val);
34*703b288fSMatti Vaittinen if (ret)
35*703b288fSMatti Vaittinen return ret;
36*703b288fSMatti Vaittinen
37*703b288fSMatti Vaittinen return (val >> offset) & 1;
38*703b288fSMatti Vaittinen }
39*703b288fSMatti Vaittinen
bd71815gpo_set(struct gpio_chip * chip,unsigned int offset,int value)40*703b288fSMatti Vaittinen static void bd71815gpo_set(struct gpio_chip *chip, unsigned int offset,
41*703b288fSMatti Vaittinen int value)
42*703b288fSMatti Vaittinen {
43*703b288fSMatti Vaittinen struct bd71815_gpio *bd71815 = gpiochip_get_data(chip);
44*703b288fSMatti Vaittinen int ret, bit;
45*703b288fSMatti Vaittinen
46*703b288fSMatti Vaittinen bit = BIT(offset);
47*703b288fSMatti Vaittinen
48*703b288fSMatti Vaittinen if (value)
49*703b288fSMatti Vaittinen ret = regmap_set_bits(bd71815->regmap, BD71815_REG_GPO, bit);
50*703b288fSMatti Vaittinen else
51*703b288fSMatti Vaittinen ret = regmap_clear_bits(bd71815->regmap, BD71815_REG_GPO, bit);
52*703b288fSMatti Vaittinen
53*703b288fSMatti Vaittinen if (ret)
54*703b288fSMatti Vaittinen dev_warn(bd71815->dev, "failed to toggle GPO\n");
55*703b288fSMatti Vaittinen }
56*703b288fSMatti Vaittinen
bd71815_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)57*703b288fSMatti Vaittinen static int bd71815_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
58*703b288fSMatti Vaittinen unsigned long config)
59*703b288fSMatti Vaittinen {
60*703b288fSMatti Vaittinen struct bd71815_gpio *bdgpio = gpiochip_get_data(chip);
61*703b288fSMatti Vaittinen
62*703b288fSMatti Vaittinen switch (pinconf_to_config_param(config)) {
63*703b288fSMatti Vaittinen case PIN_CONFIG_DRIVE_OPEN_DRAIN:
64*703b288fSMatti Vaittinen return regmap_update_bits(bdgpio->regmap,
65*703b288fSMatti Vaittinen BD71815_REG_GPO,
66*703b288fSMatti Vaittinen BD71815_GPIO_DRIVE_MASK << offset,
67*703b288fSMatti Vaittinen BD71815_GPIO_OPEN_DRAIN << offset);
68*703b288fSMatti Vaittinen case PIN_CONFIG_DRIVE_PUSH_PULL:
69*703b288fSMatti Vaittinen return regmap_update_bits(bdgpio->regmap,
70*703b288fSMatti Vaittinen BD71815_REG_GPO,
71*703b288fSMatti Vaittinen BD71815_GPIO_DRIVE_MASK << offset,
72*703b288fSMatti Vaittinen BD71815_GPIO_CMOS << offset);
73*703b288fSMatti Vaittinen default:
74*703b288fSMatti Vaittinen break;
75*703b288fSMatti Vaittinen }
76*703b288fSMatti Vaittinen return -ENOTSUPP;
77*703b288fSMatti Vaittinen }
78*703b288fSMatti Vaittinen
79*703b288fSMatti Vaittinen /* BD71815 GPIO is actually GPO */
bd71815gpo_direction_get(struct gpio_chip * gc,unsigned int offset)80*703b288fSMatti Vaittinen static int bd71815gpo_direction_get(struct gpio_chip *gc, unsigned int offset)
81*703b288fSMatti Vaittinen {
82*703b288fSMatti Vaittinen return GPIO_LINE_DIRECTION_OUT;
83*703b288fSMatti Vaittinen }
84*703b288fSMatti Vaittinen
85*703b288fSMatti Vaittinen /* Template for GPIO chip */
86*703b288fSMatti Vaittinen static const struct gpio_chip bd71815gpo_chip = {
87*703b288fSMatti Vaittinen .label = "bd71815",
88*703b288fSMatti Vaittinen .owner = THIS_MODULE,
89*703b288fSMatti Vaittinen .get = bd71815gpo_get,
90*703b288fSMatti Vaittinen .get_direction = bd71815gpo_direction_get,
91*703b288fSMatti Vaittinen .set = bd71815gpo_set,
92*703b288fSMatti Vaittinen .set_config = bd71815_gpio_set_config,
93*703b288fSMatti Vaittinen .can_sleep = true,
94*703b288fSMatti Vaittinen };
95*703b288fSMatti Vaittinen
96*703b288fSMatti Vaittinen #define BD71815_TWO_GPIOS GENMASK(1, 0)
97*703b288fSMatti Vaittinen #define BD71815_ONE_GPIO BIT(0)
98*703b288fSMatti Vaittinen
99*703b288fSMatti Vaittinen /*
100*703b288fSMatti Vaittinen * Sigh. The BD71815 and BD71817 were originally designed to support two GPO
101*703b288fSMatti Vaittinen * pins. At some point it was noticed the second GPO pin which is the E5 pin
102*703b288fSMatti Vaittinen * located at the center of IC is hard to use on PCB (due to the location). It
103*703b288fSMatti Vaittinen * was decided to not promote this second GPO and the pin is marked as GND in
104*703b288fSMatti Vaittinen * the datasheet. The functionality is still there though! I guess driving a GPO
105*703b288fSMatti Vaittinen * connected to the ground is a bad idea. Thus we do not support it by default.
106*703b288fSMatti Vaittinen * OTOH - the original driver written by colleagues at Embest did support
107*703b288fSMatti Vaittinen * controlling this second GPO. It is thus possible this is used in some of the
108*703b288fSMatti Vaittinen * products.
109*703b288fSMatti Vaittinen *
110*703b288fSMatti Vaittinen * This driver does not by default support configuring this second GPO
111*703b288fSMatti Vaittinen * but allows using it by providing the DT property
112*703b288fSMatti Vaittinen * "rohm,enable-hidden-gpo".
113*703b288fSMatti Vaittinen */
bd71815_init_valid_mask(struct gpio_chip * gc,unsigned long * valid_mask,unsigned int ngpios)114*703b288fSMatti Vaittinen static int bd71815_init_valid_mask(struct gpio_chip *gc,
115*703b288fSMatti Vaittinen unsigned long *valid_mask,
116*703b288fSMatti Vaittinen unsigned int ngpios)
117*703b288fSMatti Vaittinen {
118*703b288fSMatti Vaittinen if (ngpios != 2)
119*703b288fSMatti Vaittinen return 0;
120*703b288fSMatti Vaittinen
121*703b288fSMatti Vaittinen if (gc->parent && device_property_present(gc->parent,
122*703b288fSMatti Vaittinen "rohm,enable-hidden-gpo"))
123*703b288fSMatti Vaittinen *valid_mask = BD71815_TWO_GPIOS;
124*703b288fSMatti Vaittinen else
125*703b288fSMatti Vaittinen *valid_mask = BD71815_ONE_GPIO;
126*703b288fSMatti Vaittinen
127*703b288fSMatti Vaittinen return 0;
128*703b288fSMatti Vaittinen }
129*703b288fSMatti Vaittinen
gpo_bd71815_probe(struct platform_device * pdev)130*703b288fSMatti Vaittinen static int gpo_bd71815_probe(struct platform_device *pdev)
131*703b288fSMatti Vaittinen {
132*703b288fSMatti Vaittinen struct bd71815_gpio *g;
133*703b288fSMatti Vaittinen struct device *parent, *dev;
134*703b288fSMatti Vaittinen
135*703b288fSMatti Vaittinen /*
136*703b288fSMatti Vaittinen * Bind devm lifetime to this platform device => use dev for devm.
137*703b288fSMatti Vaittinen * also the prints should originate from this device.
138*703b288fSMatti Vaittinen */
139*703b288fSMatti Vaittinen dev = &pdev->dev;
140*703b288fSMatti Vaittinen /* The device-tree and regmap come from MFD => use parent for that */
141*703b288fSMatti Vaittinen parent = dev->parent;
142*703b288fSMatti Vaittinen
143*703b288fSMatti Vaittinen g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
144*703b288fSMatti Vaittinen if (!g)
145*703b288fSMatti Vaittinen return -ENOMEM;
146*703b288fSMatti Vaittinen
147*703b288fSMatti Vaittinen g->chip = bd71815gpo_chip;
148*703b288fSMatti Vaittinen
149*703b288fSMatti Vaittinen /*
150*703b288fSMatti Vaittinen * FIXME: As writing of this the sysfs interface for GPIO control does
151*703b288fSMatti Vaittinen * not respect the valid_mask. Do not trust it but rather set the ngpios
152*703b288fSMatti Vaittinen * to 1 if "rohm,enable-hidden-gpo" is not given.
153*703b288fSMatti Vaittinen *
154*703b288fSMatti Vaittinen * This check can be removed later if the sysfs export is fixed and
155*703b288fSMatti Vaittinen * if the fix is backported.
156*703b288fSMatti Vaittinen *
157*703b288fSMatti Vaittinen * For now it is safest to just set the ngpios though.
158*703b288fSMatti Vaittinen */
159*703b288fSMatti Vaittinen if (device_property_present(parent, "rohm,enable-hidden-gpo"))
160*703b288fSMatti Vaittinen g->chip.ngpio = 2;
161*703b288fSMatti Vaittinen else
162*703b288fSMatti Vaittinen g->chip.ngpio = 1;
163*703b288fSMatti Vaittinen
164*703b288fSMatti Vaittinen g->chip.init_valid_mask = bd71815_init_valid_mask;
165*703b288fSMatti Vaittinen g->chip.base = -1;
166*703b288fSMatti Vaittinen g->chip.parent = parent;
167*703b288fSMatti Vaittinen g->regmap = dev_get_regmap(parent, NULL);
168*703b288fSMatti Vaittinen g->dev = dev;
169*703b288fSMatti Vaittinen
170*703b288fSMatti Vaittinen return devm_gpiochip_add_data(dev, &g->chip, g);
171*703b288fSMatti Vaittinen }
172*703b288fSMatti Vaittinen
173*703b288fSMatti Vaittinen static struct platform_driver gpo_bd71815_driver = {
174*703b288fSMatti Vaittinen .driver = {
175*703b288fSMatti Vaittinen .name = "bd71815-gpo",
176*703b288fSMatti Vaittinen },
177*703b288fSMatti Vaittinen .probe = gpo_bd71815_probe,
178*703b288fSMatti Vaittinen };
179*703b288fSMatti Vaittinen module_platform_driver(gpo_bd71815_driver);
180*703b288fSMatti Vaittinen
181*703b288fSMatti Vaittinen MODULE_ALIAS("platform:bd71815-gpo");
182*703b288fSMatti Vaittinen MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
183*703b288fSMatti Vaittinen MODULE_AUTHOR("Peter Yang <yanglsh@embest-tech.com>");
184*703b288fSMatti Vaittinen MODULE_DESCRIPTION("GPO interface for BD71815");
185*703b288fSMatti Vaittinen MODULE_LICENSE("GPL");
186