[PATCH v3] gpio: UniPhier: add driver for UniPhier GPIO controller

From: Masahiro Yamada
Date: Mon Jul 13 2015 - 22:43:59 EST

This GPIO controller device is used on UniPhier SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v3:
- Use module_platform_driver()

Changes in v2:
- Fix typos in the comment block

drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-uniphier.c | 262 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 269 insertions(+)
create mode 100644 drivers/gpio/gpio-uniphier.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 4c9fa58..37cb4f2 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -462,6 +462,12 @@ config GPIO_TZ1090_PDC
help
Say yes here to support Toumaz Xenif TZ1090 PDC GPIOs.

+config GPIO_UNIPHIER
+ tristate "UniPhier GPIO"
+ depends on ARCH_UNIPHIER && OF_GPIO
+ help
+ Say yes here to support UniPhier GPIOs.
+
config GPIO_VF610
def_bool y
depends on ARCH_MXC && SOC_VF610
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f82cd67..3538b0c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -102,6 +102,7 @@ obj-$(CONFIG_GPIO_TWL6040) += gpio-twl6040.o
obj-$(CONFIG_GPIO_TZ1090) += gpio-tz1090.o
obj-$(CONFIG_GPIO_TZ1090_PDC) += gpio-tz1090-pdc.o
obj-$(CONFIG_GPIO_UCB1400) += gpio-ucb1400.o
+obj-$(CONFIG_GPIO_UNIPHIER) += gpio-uniphier.o
obj-$(CONFIG_GPIO_VF610) += gpio-vf610.o
obj-$(CONFIG_GPIO_VIPERBOARD) += gpio-viperboard.o
obj-$(CONFIG_GPIO_VR41XX) += gpio-vr41xx.o
diff --git a/drivers/gpio/gpio-uniphier.c b/drivers/gpio/gpio-uniphier.c
new file mode 100644
index 0000000..1afacaa
--- /dev/null
+++ b/drivers/gpio/gpio-uniphier.c
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+/*
+ * Unfortunately, the hardware specification adopts weird GPIO pin labeling.
+ * The ports are named as
+ * PORT00, PORT01, PORT02, ..., PORT07,
+ * PORT10, PORT11, PORT12, ..., PORT17,
+ * PORT20, PORT21, PORT22, ..., PORT27,
+ * ...
+ * PORT90, PORT91, PORT92, ..., PORT97,
+ * PORT100, PORT101, PORT102, ..., PORT107,
+ * ...
+ *
+ * The PORTs with 8 or 9 in the one's place are missing, i.e. the one's place
+ * is octal, while the other places are decimal. If we handle the port numbers
+ * as seen in the hardware documents, the GPIO offsets must be non-contiguous.
+ * It is possible to have sparse GPIO pins, but not handy for GPIO range
+ * mappings, register accessing, etc.
+ *
+ * To make things simpler (for driver and device tree implementation), this
+ * driver takes contiguously-numbered GPIO offsets. GPIO consumers should make
+ * sure to convert the PORT number into the one that fits in this driver.
+ * The conversion logic is very easy math, for example,
+ * PORT15 --> GPIO offset 13 (8 * 1 + 5)
+ * PORT123 --> GPIO offset 99 (8 * 12 + 3)
+ */
+#define UNIPHIER_GPIO_PORTS_PER_BANK 8
+#define UNIPHIER_GPIO_BANK_MASK \
+ ((1UL << (UNIPHIER_GPIO_PORTS_PER_BANK)) - 1)
+
+#define UNIPHIER_GPIO_REG_DATA 0 /* data */
+#define UNIPHIER_GPIO_REG_DIR 4 /* direction (1:in, 0:out) */
+
+struct uniphier_gpio_priv {
+ struct of_mm_gpio_chip mmchip;
+ spinlock_t lock;
+};
+
+static unsigned uniphier_gpio_bank_to_reg(unsigned bank, unsigned reg_type)
+{
+ unsigned reg;
+
+ reg = (bank + 1) * 8 + reg_type;
+
+ /*
+ * Unfortunately, there is a register hole at offset 0x90-0x9f.
+ * Add 0x10 when crossing the hole.
+ */
+ if (reg >= 0x90)
+ reg += 0x10;
+
+ return reg;
+}
+
+static void uniphier_gpio_bank_write(struct gpio_chip *chip,
+ unsigned bank, unsigned reg_type,
+ unsigned mask, unsigned value)
+{
+ struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+ struct uniphier_gpio_priv *priv;
+ unsigned long flags;
+ unsigned reg;
+ u32 tmp;
+
+ if (!mask)
+ return;
+
+ priv = container_of(mmchip, struct uniphier_gpio_priv, mmchip);
+
+ reg = uniphier_gpio_bank_to_reg(bank, reg_type);
+
+ /*
+ * Note
+ * regmap_update_bits() should not be used here.
+ *
+ * The DATA registers return the current readback of pins, not the
+ * previously written data when they are configured as "input".
+ * The DATA registers must be overwritten even if the data you are
+ * going to write is the same as what readl() has returned.
+ *
+ * regmap_update_bits() does not write back if the data is not changed.
+ */
+ spin_lock_irqsave(&priv->lock, flags);
+ tmp = readl(mmchip->regs + reg);
+ tmp &= ~mask;
+ tmp |= mask & value;
+ writel(tmp, mmchip->regs + reg);
+ spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static void uniphier_gpio_offset_write(struct gpio_chip *chip, unsigned offset,
+ unsigned reg_type, int value)
+{
+ unsigned bank = offset / UNIPHIER_GPIO_PORTS_PER_BANK;
+ unsigned bit = offset % UNIPHIER_GPIO_PORTS_PER_BANK;
+
+ uniphier_gpio_bank_write(chip, bank, reg_type, BIT(bit), value << bit);
+}
+
+static int uniphier_gpio_offset_read(struct gpio_chip *chip, unsigned offset,
+ unsigned reg_type)
+{
+ struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+ unsigned bank = offset / UNIPHIER_GPIO_PORTS_PER_BANK;
+ unsigned bit = offset % UNIPHIER_GPIO_PORTS_PER_BANK;
+ unsigned reg;
+
+ reg = uniphier_gpio_bank_to_reg(bank, reg_type);
+
+ return readl(mmchip->regs + reg) & BIT(bit) ? 1 : 0;
+}
+
+static int uniphier_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void uniphier_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+ pinctrl_free_gpio(chip->base + offset);
+}
+
+static int uniphier_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+ return uniphier_gpio_offset_read(chip, UNIPHIER_GPIO_REG_DIR, offset) ?
+ GPIOF_DIR_IN : GPIOF_DIR_OUT;
+}
+
+static int uniphier_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_REG_DIR, 1);
+
+ return 0;
+}
+
+static int uniphier_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_REG_DATA, value);
+ uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_REG_DIR, 0);
+
+ return 0;
+}
+
+static int uniphier_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_REG_DATA);
+}
+
+static void uniphier_gpio_set(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_REG_DATA, value);
+}
+
+static void uniphier_gpio_set_multiple(struct gpio_chip *chip,
+ unsigned long *mask,
+ unsigned long *bits)
+{
+ unsigned bank, shift, bank_mask, bank_bits;
+ int i;
+
+ for (i = 0; i < chip->ngpio; i += UNIPHIER_GPIO_PORTS_PER_BANK) {
+ bank = i / UNIPHIER_GPIO_PORTS_PER_BANK;
+ shift = i % BITS_PER_LONG;
+ bank_mask = (mask[BIT_WORD(i)] >> shift) &
+ UNIPHIER_GPIO_BANK_MASK;
+ bank_bits = bits[BIT_WORD(i)] >> shift;
+
+ uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_REG_DATA,
+ bank_mask, bank_bits);
+ }
+}
+
+static int uniphier_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct uniphier_gpio_priv *priv;
+ u32 ngpio;
+ int ret;
+
+ ret = of_property_read_u32(dev->of_node, "ngpio", &ngpio);
+ if (ret) {
+ dev_err(dev, "failed to get ngpio property\n");
+ return ret;
+ }
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ spin_lock_init(&priv->lock);
+
+ priv->mmchip.gc.dev = dev;
+ priv->mmchip.gc.owner = THIS_MODULE;
+ priv->mmchip.gc.request = uniphier_gpio_request;
+ priv->mmchip.gc.free = uniphier_gpio_free;
+ priv->mmchip.gc.get_direction = uniphier_gpio_get_direction;
+ priv->mmchip.gc.direction_input = uniphier_gpio_direction_input;
+ priv->mmchip.gc.direction_output = uniphier_gpio_direction_output;
+ priv->mmchip.gc.get = uniphier_gpio_get;
+ priv->mmchip.gc.set = uniphier_gpio_set;
+ priv->mmchip.gc.set_multiple = uniphier_gpio_set_multiple;
+ priv->mmchip.gc.ngpio = ngpio;
+
+ ret = of_mm_gpiochip_add(dev->of_node, &priv->mmchip);
+ if (ret) {
+ dev_err(dev, "failed to add memory mapped gpiochip\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static int uniphier_gpio_remove(struct platform_device *pdev)
+{
+ struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
+
+ of_mm_gpiochip_remove(&priv->mmchip);
+
+ return 0;
+}
+
+static const struct of_device_id uniphier_gpio_match[] = {
+ { .compatible = "socionext,uniphier-gpio" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
+
+static struct platform_driver uniphier_gpio_driver = {
+ .probe = uniphier_gpio_probe,
+ .remove = uniphier_gpio_remove,
+ .driver = {
+ .name = "uniphier-gpio",
+ .of_match_table = uniphier_gpio_match,
+ },
+};
+module_platform_driver(uniphier_gpio_driver);
+
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("UniPhier GPIO driver");
+MODULE_LICENSE("GPL");
--
1.9.1

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