Nomadik GPIO is a fairly simple GPIO module used in the ST-Ericsson Ux500 SoCs (and some older Nomadik SoCs). It uses registers where each GPIO is represented as a single bit, plus "set" and "clear" registers that allow updating the state without having to read the existing state.
The driver implements support for it for use together with DM_GPIO and the existing ste-dbx5x0.dtsi device tree.
Cc: Linus Walleij linus.walleij@linaro.org Signed-off-by: Stephan Gerhold stephan@gerhold.net ---
drivers/gpio/Kconfig | 8 +++ drivers/gpio/Makefile | 1 + drivers/gpio/nmk_gpio.c | 125 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 134 insertions(+) create mode 100644 drivers/gpio/nmk_gpio.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index de4dc51d4b..0817b12c5f 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -495,4 +495,12 @@ config NX_GPIO The GPIOs for a device are defined in the device tree with one node for each bank.
+config NOMADIK_GPIO + bool "Nomadik GPIO driver" + depends on DM_GPIO + help + Support GPIO access on ST-Ericsson Ux500 SoCs. The GPIOs are arranged + into a number of banks each with 32 GPIOs. The GPIOs for a device are + defined in the device tree with one node for each bank. + endmenu diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 3da0d2eb33..3de9734724 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -68,3 +68,4 @@ obj-$(CONFIG_MT7621_GPIO) += mt7621_gpio.o obj-$(CONFIG_MSCC_SGPIO) += mscc_sgpio.o obj-$(CONFIG_NX_GPIO) += nx_gpio.o obj-$(CONFIG_SIFIVE_GPIO) += sifive-gpio.o +obj-$(CONFIG_NOMADIK_GPIO) += nmk_gpio.o diff --git a/drivers/gpio/nmk_gpio.c b/drivers/gpio/nmk_gpio.c new file mode 100644 index 0000000000..e1bb41b196 --- /dev/null +++ b/drivers/gpio/nmk_gpio.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* Copyright (C) 2019 Stephan Gerhold */ + +#include <common.h> +#include <dm.h> +#include <asm/gpio.h> +#include <asm/io.h> + +struct nmk_gpio_regs { + u32 dat; /* data */ + u32 dats; /* data set */ + u32 datc; /* data clear */ + u32 pdis; /* pull disable */ + u32 dir; /* direction */ + u32 dirs; /* direction set */ + u32 dirc; /* direction clear */ + u32 slpm; /* sleep mode */ + u32 afsla; /* alternate function select A */ + u32 afslb; /* alternate function select B */ + u32 lowemi; /* low EMI mode */ +}; + +struct nmk_gpio { + struct nmk_gpio_regs *regs; +}; + +static int nmk_gpio_get_value(struct udevice *dev, unsigned offset) +{ + struct nmk_gpio *priv = dev_get_priv(dev); + + return !!(readl(&priv->regs->dat) & BIT(offset)); +} + +static int nmk_gpio_set_value(struct udevice *dev, unsigned offset, int value) +{ + struct nmk_gpio *priv = dev_get_priv(dev); + + if (value) + writel(BIT(offset), &priv->regs->dats); + else + writel(BIT(offset), &priv->regs->datc); + + return 0; +} + +static int nmk_gpio_get_function(struct udevice *dev, unsigned offset) +{ + struct nmk_gpio *priv = dev_get_priv(dev); + + if (readl(&priv->regs->afsla) & BIT(offset) || + readl(&priv->regs->afslb) & BIT(offset)) + return GPIOF_FUNC; + + if (readl(&priv->regs->dir) & BIT(offset)) + return GPIOF_OUTPUT; + else + return GPIOF_INPUT; +} + +static int nmk_gpio_direction_input(struct udevice *dev, unsigned offset) +{ + struct nmk_gpio *priv = dev_get_priv(dev); + + writel(BIT(offset), &priv->regs->dirc); + return 0; +} + +static int nmk_gpio_direction_output(struct udevice *dev, unsigned offset, + int value) +{ + struct nmk_gpio *priv = dev_get_priv(dev); + + writel(BIT(offset), &priv->regs->dirs); + return nmk_gpio_set_value(dev, offset, value); +} + +static const struct dm_gpio_ops nmk_gpio_ops = { + .get_value = nmk_gpio_get_value, + .set_value = nmk_gpio_set_value, + .get_function = nmk_gpio_get_function, + .direction_input = nmk_gpio_direction_input, + .direction_output = nmk_gpio_direction_output, +}; + +static int nmk_gpio_probe(struct udevice *dev) +{ + struct nmk_gpio *priv = dev_get_priv(dev); + struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); + char buf[20]; + u32 bank; + int ret; + + priv->regs = dev_read_addr_ptr(dev); + if (!priv->regs) + return -EINVAL; + + ret = dev_read_u32(dev, "gpio-bank", &bank); + if (ret < 0) { + printf("nmk_gpio(%s): Failed to read gpio-bank\n", dev->name); + return ret; + } + + sprintf(buf, "nmk%u-gpio", bank); + uc_priv->bank_name = strdup(buf); + if (!uc_priv->bank_name) + return -ENOMEM; + + uc_priv->gpio_count = sizeof(priv->regs->dat) * BITS_PER_BYTE; + + return 0; +} + +static const struct udevice_id nmk_gpio_ids[] = { + { .compatible = "st,nomadik-gpio" }, + { } +}; + +U_BOOT_DRIVER(gpio_nmk) = { + .name = "nmk_gpio", + .id = UCLASS_GPIO, + .of_match = nmk_gpio_ids, + .probe = nmk_gpio_probe, + .ops = &nmk_gpio_ops, + .priv_auto = sizeof(struct nmk_gpio), +};