Add single-register MMIO GPIO driver for complex cases where
only several fields in register belong to GPIO lines and each GPIO
line owns a field with different length and on/off value.
Such CREG GPIOs are used in Synopsys AXS10x and HSDK boards.
Signed-off-by: Eugeniy Paltsev <eugeniy.palt...@synopsys.com>
---
Changes v2->v3:
* Move parameters into a lookup table instead of device tree.
* Use the ngpios attribute for instead of snps,ngpios.
MAINTAINERS | 6 ++
drivers/gpio/Kconfig | 10 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-creg-snps.c | 212 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 229 insertions(+)
create mode 100644 drivers/gpio/gpio-creg-snps.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 544cac829cf4..e731f2f9648a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13734,6 +13734,12 @@ S: Supported
F: drivers/reset/reset-axs10x.c
F: Documentation/devicetree/bindings/reset/snps,axs10x-reset.txt
+SYNOPSYS CREG GPIO DRIVER
+M: Eugeniy Paltsev <eugeniy.palt...@synopsys.com>
+S: Maintained
+F: drivers/gpio/gpio-creg-snps.c
+F: Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt
+
SYNOPSYS DESIGNWARE 8250 UART DRIVER
R: Andy Shevchenko <andriy.shevche...@linux.intel.com>
S: Maintained
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 71c0ab46f216..78155ac22b0c 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -430,6 +430,16 @@ config GPIO_REG
A 32-bit single register GPIO fixed in/out implementation. This
can be used to represent any register as a set of GPIO signals.
+config GPIO_SNPS_CREG
+ bool "Synopsys GPIO via CREG (Control REGisters) driver"
+ depends on ARC || COMPILE_TEST
+ select OF_GPIO
+ help
+ This driver supports GPIOs via CREG on various Synopsys SoCs.
+ This is a single-register MMIO GPIO driver for complex cases
+ where only several fields in register belong to GPIO lines and
+ each GPIO line owns a field with different length and on/off value.
+
config GPIO_SPEAR_SPICS
bool "ST SPEAr13xx SPI Chip Select as GPIO support"
depends on PLAT_SPEAR
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 1324c8f966a7..993f8ad54a19 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_GPIO_REG) += gpio-reg.o
obj-$(CONFIG_ARCH_SA1100) += gpio-sa1100.o
obj-$(CONFIG_GPIO_SCH) += gpio-sch.o
obj-$(CONFIG_GPIO_SCH311X) += gpio-sch311x.o
+obj-$(CONFIG_GPIO_SNPS_CREG) += gpio-creg-snps.o
obj-$(CONFIG_GPIO_SODAVILLE) += gpio-sodaville.o
obj-$(CONFIG_GPIO_SPEAR_SPICS) += gpio-spear-spics.o
obj-$(CONFIG_GPIO_SPRD) += gpio-sprd.o
diff --git a/drivers/gpio/gpio-creg-snps.c b/drivers/gpio/gpio-creg-snps.c
new file mode 100644
index 000000000000..2400dec529b2
--- /dev/null
+++ b/drivers/gpio/gpio-creg-snps.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Synopsys CREG (Control REGisters) GPIO driver
+//
+// Copyright (C) 2018 Synopsys
+// Author: Eugeniy Paltsev <eugeniy.palt...@synopsys.com>
+
+#include <linux/of.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/of_gpio.h>
+#include <linux/io.h>
+#include <linux/of_platform.h>
+#include <linux/module.h>
+
+#include "gpiolib.h"
+
+#define MAX_GPIO 32
+
+struct creg_layout {
+ u8 ngpio;
+ u8 shift[MAX_GPIO];
+ u8 on[MAX_GPIO];
+ u8 off[MAX_GPIO];
+ u8 bit_per_gpio[MAX_GPIO];
+};
+
+struct creg_gpio {
+ struct of_mm_gpio_chip mmchip;
+ spinlock_t lock;
+ const struct creg_layout *layout;
+};
+
+static void creg_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ struct creg_gpio *hcg = gpiochip_get_data(gc);
+ const struct creg_layout *layout = hcg->layout;
+ u32 reg, reg_shift, value;
+ unsigned long flags;
+ int i;
+
+ value = val ? hcg->layout->on[gpio] : hcg->layout->off[gpio];
+
+ reg_shift = layout->shift[gpio];
+ for (i = 0; i < gpio; i++)
+ reg_shift += layout->bit_per_gpio[i] + layout->shift[i];
+
+ spin_lock_irqsave(&hcg->lock, flags);
+ reg = readl(hcg->mmchip.regs);
+ reg &= ~(GENMASK(layout->bit_per_gpio[i] - 1, 0) << reg_shift);
+ reg |= (value << reg_shift);
+ writel(reg, hcg->mmchip.regs);
+ spin_unlock_irqrestore(&hcg->lock, flags);
+}
+
+static int creg_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ creg_gpio_set(gc, gpio, val);
+
+ return 0;
+}
+
+static int creg_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ return 0; /* output */
+}
+
+static int creg_gpio_xlate(struct gpio_chip *gc,
+ const struct of_phandle_args *gpiospec, u32 *flags)
+{
+ if (gpiospec->args_count != 1) {
+ dev_err(&gc->gpiodev->dev, "invalid args_count: %d\n",
+ gpiospec->args_count);
+ return -EINVAL;
+ }
+
+ if (gpiospec->args[0] >= gc->ngpio) {
+ dev_err(&gc->gpiodev->dev, "gpio number is too big: %d\n",
+ gpiospec->args[0]);
+ return -EINVAL;
+ }
+
+ return gpiospec->args[0];
+}
+
+static int creg_gpio_validate_pg(struct device *dev, struct creg_gpio *hcg,
+ int i)
+{
+ const struct creg_layout *layout = hcg->layout;
+
+ if (layout->bit_per_gpio[i] < 1 || layout->bit_per_gpio[i] > 8)
+ return -EINVAL;
+
+ /* Check that on valiue suits it's placeholder */
+ if (GENMASK(31, layout->bit_per_gpio[i]) & layout->on[i])
+ return -EINVAL;
+
+ /* Check that off valiue suits it's placeholder */
+ if (GENMASK(31, layout->bit_per_gpio[i]) & layout->off[i])
+ return -EINVAL;
+
+ if (layout->on[i] == layout->off[i])
+ return -EINVAL;
+
+ return 0;
+}
+
+static int creg_gpio_validate(struct device *dev, struct creg_gpio *hcg,
+ u32 ngpios)
+{
+ u32 reg_len = 0;
+ int i;
+
+ if (hcg->layout->ngpio < 1 || hcg->layout->ngpio > MAX_GPIO)
+ return -EINVAL;
+
+ if (ngpios < 1 || ngpios > hcg->layout->ngpio) {
+ dev_err(dev, "ngpios must be in [1:%u]\n", hcg->layout->ngpio);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < hcg->layout->ngpio; i++) {
+ if (creg_gpio_validate_pg(dev, hcg, i))
+ return -EINVAL;
+
+ reg_len += hcg->layout->shift[i] + hcg->layout->bit_per_gpio[i];
+ }
+
+ /* Check that we suit in 32 bit register */
+ if (reg_len > 32)
+ return -EINVAL;
+
+ return 0;
+}
+
+static const struct creg_layout hsdk_cs_ctl = {
+ .ngpio = 10,
+ .shift = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
+ .off = { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 },
+ .on = { 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 },
+ .bit_per_gpio = { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 }
+};
+
+static const struct creg_layout axs10x_flsh_cs_ctl = {
+ .ngpio = 1,
+ .shift = { 0 },
+ .off = { 1 },
+ .on = { 3 },
+ .bit_per_gpio = { 2 }
+};
+
+static const struct of_device_id creg_gpio_ids[] = {
+ {
+ .compatible = "snps,creg-gpio-axs10x",
+ .data = &axs10x_flsh_cs_ctl
+ }, {
+ .compatible = "snps,creg-gpio-hsdk",
+ .data = &hsdk_cs_ctl
+ }, { /* sentinel */ }
+};
+
+static int creg_gpio_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ struct device *dev = &pdev->dev;
+ struct creg_gpio *hcg;
+ u32 ngpios;
+ int ret;
+
+ hcg = devm_kzalloc(dev, sizeof(struct creg_gpio), GFP_KERNEL);
+ if (!hcg)
+ return -ENOMEM;
+
+ match = of_match_node(creg_gpio_ids, pdev->dev.of_node);
+ hcg->layout = match->data;
+ if (!hcg->layout)
+ return -EINVAL;
+
+ ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
+ if (ret)
+ return ret;
+
+ ret = creg_gpio_validate(dev, hcg, ngpios);
+ if (ret)
+ return ret;
+
+ spin_lock_init(&hcg->lock);
+
+ hcg->mmchip.gc.ngpio = ngpios;
+ hcg->mmchip.gc.set = creg_gpio_set;
+ hcg->mmchip.gc.get_direction = creg_gpio_get_direction;
+ hcg->mmchip.gc.direction_output = creg_gpio_dir_out;
+ hcg->mmchip.gc.of_xlate = creg_gpio_xlate;
+ hcg->mmchip.gc.of_gpio_n_cells = 1;
+
+ ret = of_mm_gpiochip_add_data(pdev->dev.of_node, &hcg->mmchip, hcg);
+ if (ret)
+ return ret;
+
+ dev_info(dev, "GPIO controller with %d gpios probed\n", ngpios);
+
+ return 0;
+}
+
+static struct platform_driver creg_gpio_snps_driver = {
+ .driver = {
+ .name = "snps-creg-gpio",
+ .of_match_table = creg_gpio_ids,
+ },
+ .probe = creg_gpio_probe,
+};
+builtin_platform_driver(creg_gpio_snps_driver);
--
2.14.4
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