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185 lines
5.1 KiB
185 lines
5.1 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Support to GPOs on ROHM BD71815 |
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* Copyright 2021 ROHM Semiconductors. |
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* Author: Matti Vaittinen <[email protected]> |
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* |
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* Copyright 2014 Embest Technology Co. Ltd. Inc. |
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* Author: [email protected] |
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*/ |
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#include <linux/gpio/driver.h> |
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#include <linux/init.h> |
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#include <linux/irq.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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/* For the BD71815 register definitions */ |
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#include <linux/mfd/rohm-bd71815.h> |
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struct bd71815_gpio { |
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/* chip.parent points the MFD which provides DT node and regmap */ |
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struct gpio_chip chip; |
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/* dev points to the platform device for devm and prints */ |
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struct device *dev; |
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struct regmap *regmap; |
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}; |
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static int bd71815gpo_get(struct gpio_chip *chip, unsigned int offset) |
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{ |
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struct bd71815_gpio *bd71815 = gpiochip_get_data(chip); |
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int ret, val; |
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ret = regmap_read(bd71815->regmap, BD71815_REG_GPO, &val); |
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if (ret) |
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return ret; |
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return (val >> offset) & 1; |
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} |
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static void bd71815gpo_set(struct gpio_chip *chip, unsigned int offset, |
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int value) |
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{ |
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struct bd71815_gpio *bd71815 = gpiochip_get_data(chip); |
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int ret, bit; |
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bit = BIT(offset); |
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if (value) |
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ret = regmap_set_bits(bd71815->regmap, BD71815_REG_GPO, bit); |
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else |
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ret = regmap_clear_bits(bd71815->regmap, BD71815_REG_GPO, bit); |
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if (ret) |
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dev_warn(bd71815->dev, "failed to toggle GPO\n"); |
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} |
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static int bd71815_gpio_set_config(struct gpio_chip *chip, unsigned int offset, |
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unsigned long config) |
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{ |
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struct bd71815_gpio *bdgpio = gpiochip_get_data(chip); |
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switch (pinconf_to_config_param(config)) { |
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case PIN_CONFIG_DRIVE_OPEN_DRAIN: |
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return regmap_update_bits(bdgpio->regmap, |
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BD71815_REG_GPO, |
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BD71815_GPIO_DRIVE_MASK << offset, |
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BD71815_GPIO_OPEN_DRAIN << offset); |
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case PIN_CONFIG_DRIVE_PUSH_PULL: |
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return regmap_update_bits(bdgpio->regmap, |
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BD71815_REG_GPO, |
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BD71815_GPIO_DRIVE_MASK << offset, |
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BD71815_GPIO_CMOS << offset); |
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default: |
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break; |
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} |
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return -ENOTSUPP; |
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} |
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/* BD71815 GPIO is actually GPO */ |
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static int bd71815gpo_direction_get(struct gpio_chip *gc, unsigned int offset) |
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{ |
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return GPIO_LINE_DIRECTION_OUT; |
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} |
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/* Template for GPIO chip */ |
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static const struct gpio_chip bd71815gpo_chip = { |
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.label = "bd71815", |
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.owner = THIS_MODULE, |
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.get = bd71815gpo_get, |
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.get_direction = bd71815gpo_direction_get, |
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.set = bd71815gpo_set, |
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.set_config = bd71815_gpio_set_config, |
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.can_sleep = true, |
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}; |
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#define BD71815_TWO_GPIOS GENMASK(1, 0) |
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#define BD71815_ONE_GPIO BIT(0) |
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/* |
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* Sigh. The BD71815 and BD71817 were originally designed to support two GPO |
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* pins. At some point it was noticed the second GPO pin which is the E5 pin |
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* located at the center of IC is hard to use on PCB (due to the location). It |
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* was decided to not promote this second GPO and the pin is marked as GND in |
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* the datasheet. The functionality is still there though! I guess driving a GPO |
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* connected to the ground is a bad idea. Thus we do not support it by default. |
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* OTOH - the original driver written by colleagues at Embest did support |
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* controlling this second GPO. It is thus possible this is used in some of the |
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* products. |
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* |
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* This driver does not by default support configuring this second GPO |
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* but allows using it by providing the DT property |
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* "rohm,enable-hidden-gpo". |
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*/ |
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static int bd71815_init_valid_mask(struct gpio_chip *gc, |
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unsigned long *valid_mask, |
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unsigned int ngpios) |
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{ |
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if (ngpios != 2) |
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return 0; |
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if (gc->parent && device_property_present(gc->parent, |
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"rohm,enable-hidden-gpo")) |
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*valid_mask = BD71815_TWO_GPIOS; |
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else |
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*valid_mask = BD71815_ONE_GPIO; |
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return 0; |
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} |
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static int gpo_bd71815_probe(struct platform_device *pdev) |
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{ |
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struct bd71815_gpio *g; |
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struct device *parent, *dev; |
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/* |
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* Bind devm lifetime to this platform device => use dev for devm. |
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* also the prints should originate from this device. |
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*/ |
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dev = &pdev->dev; |
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/* The device-tree and regmap come from MFD => use parent for that */ |
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parent = dev->parent; |
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g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL); |
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if (!g) |
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return -ENOMEM; |
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g->chip = bd71815gpo_chip; |
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/* |
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* FIXME: As writing of this the sysfs interface for GPIO control does |
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* not respect the valid_mask. Do not trust it but rather set the ngpios |
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* to 1 if "rohm,enable-hidden-gpo" is not given. |
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* |
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* This check can be removed later if the sysfs export is fixed and |
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* if the fix is backported. |
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* |
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* For now it is safest to just set the ngpios though. |
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*/ |
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if (device_property_present(parent, "rohm,enable-hidden-gpo")) |
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g->chip.ngpio = 2; |
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else |
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g->chip.ngpio = 1; |
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g->chip.init_valid_mask = bd71815_init_valid_mask; |
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g->chip.base = -1; |
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g->chip.parent = parent; |
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g->regmap = dev_get_regmap(parent, NULL); |
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g->dev = dev; |
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return devm_gpiochip_add_data(dev, &g->chip, g); |
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} |
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static struct platform_driver gpo_bd71815_driver = { |
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.driver = { |
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.name = "bd71815-gpo", |
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}, |
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.probe = gpo_bd71815_probe, |
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}; |
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module_platform_driver(gpo_bd71815_driver); |
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MODULE_ALIAS("platform:bd71815-gpo"); |
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MODULE_AUTHOR("Matti Vaittinen <[email protected]>"); |
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MODULE_AUTHOR("Peter Yang <[email protected]>"); |
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MODULE_DESCRIPTION("GPO interface for BD71815"); |
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MODULE_LICENSE("GPL");
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