[PATCH v2] gpio: Add Intel gpio controller support
Tomas Marek
tomas.marek at elrest.cz
Wed Apr 10 09:34:46 PDT 2024
Signed-off-by: Tomas Marek <tomas.marek at elrest.cz>
---
Changes in v2:
- Addressed comments from Ahmad - mainly fixing the return value of
intel_gpio_get_direction, and implementing the add_intel_gpio_device
helper.
- Link to v1: https://lore.barebox.org/barebox/20240409071422.5934-1-tomas.marek@elrest.cz/
---
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-intel.c | 198 +++++++++++++++++++++++++++++
include/platform_data/gpio-intel.h | 23 ++++
4 files changed, 228 insertions(+)
create mode 100644 drivers/gpio/gpio-intel.c
create mode 100644 include/platform_data/gpio-intel.h
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 9f27addaa2..d9bb68e06b 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -219,6 +219,12 @@ config GPIO_LATCH
Say yes here to enable a driver for GPIO multiplexers based on latches
connected to other GPIOs.
+config GPIO_INTEL
+ bool "Intel GPIO driver"
+ depends on X86 || COMPILE_TEST
+ help
+ Say Y here to build support for the Intel GPIO driver.
+
endmenu
endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 628e975285..b0575ccf8c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_GPIO_SIFIVE) += gpio-sifive.o
obj-$(CONFIG_GPIO_STARFIVE) += gpio-starfive-vic.o
obj-$(CONFIG_GPIO_ZYNQ) += gpio-zynq.o
obj-$(CONFIG_GPIO_LATCH) += gpio-latch.o
+obj-$(CONFIG_GPIO_INTEL) += gpio-intel.o
diff --git a/drivers/gpio/gpio-intel.c b/drivers/gpio/gpio-intel.c
new file mode 100644
index 0000000000..ebec220f46
--- /dev/null
+++ b/drivers/gpio/gpio-intel.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: 2004 Tomas Marek, Elrest Solutions Company s.r.o.
+
+/*
+ * Based on the Linux kernel v6.8 drivers/pinctrl/intel/pinctrl-intel.c.
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <io.h>
+#include <gpio.h>
+
+#include <platform_data/gpio-intel.h>
+
+#define PADBAR 0x00c
+
+/* Offset from pad_regs */
+#define PADCFG0 0x000
+#define PADCFG0_RXEVCFG_MASK GENMASK(26, 25)
+#define PADCFG0_RXEVCFG_LEVEL (0 << 25)
+#define PADCFG0_RXEVCFG_EDGE (1 << 25)
+#define PADCFG0_RXEVCFG_DISABLED (2 << 25)
+#define PADCFG0_RXEVCFG_EDGE_BOTH (3 << 25)
+#define PADCFG0_PREGFRXSEL BIT(24)
+#define PADCFG0_RXINV BIT(23)
+#define PADCFG0_GPIROUTIOXAPIC BIT(20)
+#define PADCFG0_GPIROUTSCI BIT(19)
+#define PADCFG0_GPIROUTSMI BIT(18)
+#define PADCFG0_GPIROUTNMI BIT(17)
+#define PADCFG0_PMODE_SHIFT 10
+#define PADCFG0_PMODE_MASK GENMASK(13, 10)
+#define PADCFG0_PMODE_GPIO 0
+#define PADCFG0_GPIORXDIS BIT(9)
+#define PADCFG0_GPIOTXDIS BIT(8)
+#define PADCFG0_GPIORXSTATE BIT(1)
+#define PADCFG0_GPIOTXSTATE BIT(0)
+
+struct intel_gpio_chip {
+ struct gpio_chip chip;
+ void __iomem *community_pad_base;
+};
+
+static inline struct intel_gpio_chip *to_intel_gpio(struct gpio_chip *gc)
+{
+ return container_of(gc, struct intel_gpio_chip, chip);
+}
+
+static void __iomem *intel_gpio_padcfg0_reg(const struct intel_gpio_chip *chip,
+ const unsigned int gpio)
+{
+ const u32 pad_cfg_offset = 16;
+
+ return chip->community_pad_base + pad_cfg_offset * gpio;
+}
+
+static u32 intel_gpio_padcfg0_value(const struct intel_gpio_chip *chip,
+ const unsigned int gpio)
+{
+ return readl(intel_gpio_padcfg0_reg(chip, gpio));
+}
+
+static void intel_gpio_padcfg0_write(const struct intel_gpio_chip *chip,
+ const unsigned int gpio, u32 value)
+{
+ writel(value, intel_gpio_padcfg0_reg(chip, gpio));
+}
+
+static void intel_gpio_set_value(struct gpio_chip *gc, unsigned int gpio,
+ int value)
+{
+ struct intel_gpio_chip *chip = to_intel_gpio(gc);
+ u32 padcfg0;
+
+ padcfg0 = intel_gpio_padcfg0_value(chip, gpio);
+ if (value)
+ padcfg0 |= PADCFG0_GPIOTXSTATE;
+ else
+ padcfg0 &= ~PADCFG0_GPIOTXSTATE;
+ intel_gpio_padcfg0_write(chip, gpio, padcfg0);
+}
+
+static int intel_gpio_get_value(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct intel_gpio_chip *chip = to_intel_gpio(gc);
+ u32 padcfg0;
+
+ padcfg0 = intel_gpio_padcfg0_value(chip, gpio);
+ if (!(padcfg0 & PADCFG0_GPIOTXDIS))
+ return !!(padcfg0 & PADCFG0_GPIOTXSTATE);
+
+ return !!(padcfg0 & PADCFG0_GPIORXSTATE);
+}
+
+static int intel_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct intel_gpio_chip *chip = to_intel_gpio(gc);
+ u32 padcfg0;
+
+ padcfg0 = intel_gpio_padcfg0_value(chip, gpio);
+
+ if (padcfg0 & PADCFG0_PMODE_MASK)
+ return -EINVAL;
+
+ if (padcfg0 & PADCFG0_GPIOTXDIS)
+ return GPIOF_DIR_IN;
+
+ return GPIOF_DIR_OUT;
+}
+
+static int intel_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct intel_gpio_chip *chip = to_intel_gpio(gc);
+ u32 padcfg0;
+
+ padcfg0 = intel_gpio_padcfg0_value(chip, gpio);
+ padcfg0 &= ~PADCFG0_GPIORXDIS;
+ padcfg0 |= PADCFG0_GPIOTXDIS;
+ intel_gpio_padcfg0_write(chip, gpio, padcfg0);
+
+ return 0;
+}
+
+static int intel_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
+ int value)
+{
+ struct intel_gpio_chip *chip = to_intel_gpio(gc);
+ u32 padcfg0;
+
+ padcfg0 = intel_gpio_padcfg0_value(chip, gpio);
+ padcfg0 &= ~PADCFG0_GPIOTXDIS;
+ padcfg0 |= PADCFG0_GPIORXDIS;
+ if (value)
+ padcfg0 |= PADCFG0_GPIOTXSTATE;
+ else
+ padcfg0 &= ~PADCFG0_GPIOTXSTATE;
+ intel_gpio_padcfg0_write(chip, gpio, padcfg0);
+
+ return 0;
+}
+
+static struct gpio_ops intel_gpio_ops = {
+ .direction_input = intel_gpio_direction_input,
+ .direction_output = intel_gpio_direction_output,
+ .get_direction = intel_gpio_get_direction,
+ .get = intel_gpio_get_value,
+ .set = intel_gpio_set_value,
+};
+
+static int intel_gpio_probe(struct device *dev)
+{
+ const struct gpio_intel_platform_data *pdata;
+ struct intel_gpio_chip *intel_gpio;
+ void __iomem *community_pad_base;
+ void __iomem *community_base;
+ struct resource *iores;
+ int ret;
+
+ pdata = (struct gpio_intel_platform_data *)dev->platform_data;
+ if (!pdata) {
+ dev_err(dev, "Configuration missing!\n");
+ return -EINVAL;
+ }
+
+ iores = dev_request_mem_resource(dev, 0);
+ if (IS_ERR(iores)) {
+ dev_err(dev, "Memory resource request failed: %ld\n",
+ PTR_ERR(iores));
+ return PTR_ERR(iores);
+ }
+
+ intel_gpio = xzalloc(sizeof(*intel_gpio));
+
+ intel_gpio->chip.ops = &intel_gpio_ops;
+ intel_gpio->chip.ngpio = pdata->ngpios;
+ intel_gpio->chip.dev = dev;
+
+ community_base = IOMEM(iores->start);
+ community_pad_base = IOMEM(community_base + readl(community_base + PADBAR));
+
+ intel_gpio->community_pad_base = community_pad_base;
+
+ ret = gpiochip_add(&intel_gpio->chip);
+
+ if (ret) {
+ dev_err(dev, "Couldn't add gpiochip: %pe\n", ERR_PTR(ret));
+ kfree(intel_gpio);
+ return ret;
+ }
+
+ return 0;
+}
+
+static struct driver_d intel_gpio_driver = {
+ .name = "intel-gpio",
+ .probe = intel_gpio_probe,
+};
+
+coredevice_platform_driver(intel_gpio_driver);
diff --git a/include/platform_data/gpio-intel.h b/include/platform_data/gpio-intel.h
new file mode 100644
index 0000000000..4da4764998
--- /dev/null
+++ b/include/platform_data/gpio-intel.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __GPIO_INTEL_H
+#define __GPIO_INTEL_H
+
+#include <linux/types.h>
+
+struct gpio_intel_platform_data {
+ resource_size_t community_base;
+ resource_size_t community_size;
+ unsigned int ngpios;
+};
+
+static inline struct device *add_intel_gpio_device(
+ struct gpio_intel_platform_data *pdata
+)
+{
+ return add_generic_device("intel-gpio", DEVICE_ID_DYNAMIC, NULL,
+ pdata->community_base, pdata->community_size,
+ IORESOURCE_MEM, pdata);
+}
+
+#endif /* __GPIO_INTEL_H */
--
2.39.2
More information about the barebox
mailing list