diff options
Diffstat (limited to 'drivers/gpio/sl28cpld-gpio.c')
| -rw-r--r-- | drivers/gpio/sl28cpld-gpio.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/drivers/gpio/sl28cpld-gpio.c b/drivers/gpio/sl28cpld-gpio.c new file mode 100644 index 0000000000..700fc3df29 --- /dev/null +++ b/drivers/gpio/sl28cpld-gpio.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * GPIO driver for the sl28cpld + * + * Copyright (c) 2021 Michael Walle <michael@walle.cc> + */ + +#include <common.h> +#include <dm.h> +#include <asm/gpio.h> +#include <sl28cpld.h> + +/* GPIO flavor */ +#define SL28CPLD_GPIO_DIR 0x00 +#define SL28CPLD_GPIO_OUT 0x01 +#define SL28CPLD_GPIO_IN 0x02 + +/* input-only flavor */ +#define SL28CPLD_GPI_IN 0x00 + +/* output-only flavor */ +#define SL28CPLD_GPO_OUT 0x00 + +enum { + SL28CPLD_GPIO, + SL28CPLD_GPI, + SL28CPLD_GPO, +}; + +static int sl28cpld_gpio_get_value(struct udevice *dev, unsigned int gpio) +{ + ulong type = dev_get_driver_data(dev); + int val, reg; + + switch (type) { + case SL28CPLD_GPIO: + reg = SL28CPLD_GPIO_IN; + break; + case SL28CPLD_GPI: + reg = SL28CPLD_GPI_IN; + break; + case SL28CPLD_GPO: + /* we are output only, thus just return the output value */ + reg = SL28CPLD_GPO_OUT; + break; + default: + return -EINVAL; + } + + val = sl28cpld_read(dev, reg); + + return val < 0 ? val : !!(val & BIT(gpio)); +} + +static int sl28cpld_gpio_set_value(struct udevice *dev, unsigned int gpio, + int value) +{ + ulong type = dev_get_driver_data(dev); + uint reg; + + switch (type) { + case SL28CPLD_GPIO: + reg = SL28CPLD_GPIO_OUT; + break; + case SL28CPLD_GPO: + reg = SL28CPLD_GPO_OUT; + break; + case SL28CPLD_GPI: + default: + return -EINVAL; + } + + if (value) + return sl28cpld_update(dev, reg, 0, BIT(gpio)); + else + return sl28cpld_update(dev, reg, BIT(gpio), 0); +} + +static int sl28cpld_gpio_direction_input(struct udevice *dev, unsigned int gpio) +{ + ulong type = dev_get_driver_data(dev); + + switch (type) { + case SL28CPLD_GPI: + return 0; + case SL28CPLD_GPIO: + return sl28cpld_update(dev, SL28CPLD_GPIO_DIR, BIT(gpio), 0); + case SL28CPLD_GPO: + default: + return -EINVAL; + } +} + +static int sl28cpld_gpio_direction_output(struct udevice *dev, + unsigned int gpio, int value) +{ + ulong type = dev_get_driver_data(dev); + int ret; + + /* set_value() will report an error if we are input-only */ + ret = sl28cpld_gpio_set_value(dev, gpio, value); + if (ret) + return ret; + + if (type == SL28CPLD_GPIO) + return sl28cpld_update(dev, SL28CPLD_GPIO_DIR, 0, BIT(gpio)); + + return 0; +} + +static int sl28cpld_gpio_get_function(struct udevice *dev, unsigned int gpio) +{ + ulong type = dev_get_driver_data(dev); + int val; + + switch (type) { + case SL28CPLD_GPIO: + val = sl28cpld_read(dev, SL28CPLD_GPIO_DIR); + if (val < 0) + return val; + if (val & BIT(gpio)) + return GPIOF_OUTPUT; + else + return GPIOF_INPUT; + case SL28CPLD_GPI: + return GPIOF_INPUT; + case SL28CPLD_GPO: + return GPIOF_OUTPUT; + default: + return -EINVAL; + } +} + +static const struct dm_gpio_ops sl28cpld_gpio_ops = { + .direction_input = sl28cpld_gpio_direction_input, + .direction_output = sl28cpld_gpio_direction_output, + .get_value = sl28cpld_gpio_get_value, + .set_value = sl28cpld_gpio_set_value, + .get_function = sl28cpld_gpio_get_function, +}; + +static int sl28cpld_gpio_probe(struct udevice *dev) +{ + struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); + + uc_priv->gpio_count = 8; + uc_priv->bank_name = dev_read_name(dev); + + return 0; +} + +static const struct udevice_id sl28cpld_gpio_ids[] = { + { .compatible = "kontron,sl28cpld-gpio", .data = SL28CPLD_GPIO}, + { .compatible = "kontron,sl28cpld-gpo", .data = SL28CPLD_GPO}, + { .compatible = "kontron,sl28cpld-gpi", .data = SL28CPLD_GPI}, + { } +}; + +U_BOOT_DRIVER(sl28cpld_gpio) = { + .name = "sl28cpld_gpio", + .id = UCLASS_GPIO, + .of_match = sl28cpld_gpio_ids, + .probe = sl28cpld_gpio_probe, + .ops = &sl28cpld_gpio_ops, +}; |