diff options
Diffstat (limited to 'drivers/gpio/gpio-madera.c')
| -rw-r--r-- | drivers/gpio/gpio-madera.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-madera.c b/drivers/gpio/gpio-madera.c new file mode 100644 index 000000000000..7ba68d1a0932 --- /dev/null +++ b/drivers/gpio/gpio-madera.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GPIO support for Cirrus Logic Madera codecs + * + * Copyright (C) 2015-2018 Cirrus Logic + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by the + * Free Software Foundation; version 2. + */ + +#include <linux/gpio/driver.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <linux/mfd/madera/core.h> +#include <linux/mfd/madera/pdata.h> +#include <linux/mfd/madera/registers.h> + +struct madera_gpio { + struct madera *madera; + /* storage space for the gpio_chip we're using */ + struct gpio_chip gpio_chip; +}; + +static int madera_gpio_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + struct madera_gpio *madera_gpio = gpiochip_get_data(chip); + struct madera *madera = madera_gpio->madera; + unsigned int reg_offset = 2 * offset; + unsigned int val; + int ret; + + ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset, + &val); + if (ret < 0) + return ret; + + return !!(val & MADERA_GP1_DIR_MASK); +} + +static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset) +{ + struct madera_gpio *madera_gpio = gpiochip_get_data(chip); + struct madera *madera = madera_gpio->madera; + unsigned int reg_offset = 2 * offset; + + return regmap_update_bits(madera->regmap, + MADERA_GPIO1_CTRL_2 + reg_offset, + MADERA_GP1_DIR_MASK, MADERA_GP1_DIR); +} + +static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct madera_gpio *madera_gpio = gpiochip_get_data(chip); + struct madera *madera = madera_gpio->madera; + unsigned int reg_offset = 2 * offset; + unsigned int val; + int ret; + + ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset, + &val); + if (ret < 0) + return ret; + + return !!(val & MADERA_GP1_LVL_MASK); +} + +static int madera_gpio_direction_out(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct madera_gpio *madera_gpio = gpiochip_get_data(chip); + struct madera *madera = madera_gpio->madera; + unsigned int reg_offset = 2 * offset; + unsigned int reg_val = value ? MADERA_GP1_LVL : 0; + int ret; + + ret = regmap_update_bits(madera->regmap, + MADERA_GPIO1_CTRL_2 + reg_offset, + MADERA_GP1_DIR_MASK, 0); + if (ret < 0) + return ret; + + return regmap_update_bits(madera->regmap, + MADERA_GPIO1_CTRL_1 + reg_offset, + MADERA_GP1_LVL_MASK, reg_val); +} + +static void madera_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct madera_gpio *madera_gpio = gpiochip_get_data(chip); + struct madera *madera = madera_gpio->madera; + unsigned int reg_offset = 2 * offset; + unsigned int reg_val = value ? MADERA_GP1_LVL : 0; + int ret; + + ret = regmap_update_bits(madera->regmap, + MADERA_GPIO1_CTRL_1 + reg_offset, + MADERA_GP1_LVL_MASK, reg_val); + + /* set() doesn't return an error so log a warning */ + if (ret) + dev_warn(madera->dev, "Failed to write to 0x%x (%d)\n", + MADERA_GPIO1_CTRL_1 + reg_offset, ret); +} + +static struct gpio_chip madera_gpio_chip = { + .label = "madera", + .owner = THIS_MODULE, + .request = gpiochip_generic_request, + .free = gpiochip_generic_free, + .get_direction = madera_gpio_get_direction, + .direction_input = madera_gpio_direction_in, + .get = madera_gpio_get, + .direction_output = madera_gpio_direction_out, + .set = madera_gpio_set, + .set_config = gpiochip_generic_config, + .can_sleep = true, +}; + +static int madera_gpio_probe(struct platform_device *pdev) +{ + struct madera *madera = dev_get_drvdata(pdev->dev.parent); + struct madera_pdata *pdata = dev_get_platdata(madera->dev); + struct madera_gpio *madera_gpio; + int ret; + + madera_gpio = devm_kzalloc(&pdev->dev, sizeof(*madera_gpio), + GFP_KERNEL); + if (!madera_gpio) + return -ENOMEM; + + madera_gpio->madera = madera; + + /* Construct suitable gpio_chip from the template in madera_gpio_chip */ + madera_gpio->gpio_chip = madera_gpio_chip; + madera_gpio->gpio_chip.parent = pdev->dev.parent; + + switch (madera->type) { + case CS47L35: + madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS; + break; + case CS47L85: + case WM1840: + madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS; + break; + case CS47L90: + case CS47L91: + madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS; + break; + default: + dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type); + return -EINVAL; + } + + /* We want to be usable on systems that don't use devicetree or acpi */ + if (pdata && pdata->gpio_base) + madera_gpio->gpio_chip.base = pdata->gpio_base; + else + madera_gpio->gpio_chip.base = -1; + + ret = devm_gpiochip_add_data(&pdev->dev, + &madera_gpio->gpio_chip, + madera_gpio); + if (ret < 0) { + dev_dbg(&pdev->dev, "Could not register gpiochip, %d\n", ret); + return ret; + } + + /* + * This is part of a composite MFD device which can only be used with + * the corresponding pinctrl driver. On all supported silicon the GPIO + * to pinctrl mapping is fixed in the silicon, so we register it + * explicitly instead of requiring a redundant gpio-ranges in the + * devicetree. + * In any case we also want to work on systems that don't use devicetree + * or acpi. + */ + ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl", + 0, 0, madera_gpio->gpio_chip.ngpio); + if (ret) { + dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret); + return ret; + } + + return 0; +} + +static struct platform_driver madera_gpio_driver = { + .driver = { + .name = "madera-gpio", + }, + .probe = madera_gpio_probe, +}; + +module_platform_driver(madera_gpio_driver); + +MODULE_SOFTDEP("pre: pinctrl-madera"); +MODULE_DESCRIPTION("GPIO interface for Madera codecs"); +MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>"); +MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:madera-gpio"); |