MIPS: PMC MSP71XX gpio drivers

This new gpio driver for PMC-Sierra's MSP71xx SoC allows
standard api calls for access to the general and extended
gpio's.

Signed-off-by: Patrick Glass <patrickglass@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

 create mode 100755 arch/mips/pmc-sierra/msp71xx/gpio.c
 create mode 100755 arch/mips/pmc-sierra/msp71xx/gpio_extended.c
 create mode 100755 include/asm-mips/pmc-sierra/msp71xx/gpio.h

1 files changed, 148 insertions, 0 deletions

diff --git a/arch/mips/pmc-sierra/msp71xx/gpio_extended.c b/arch/mips/pmc-sierra/msp71xx/gpio_extended.c
new file mode 100644
index 00000000000..fc6dbc6cf1c
--- /dev/null
+++ b/arch/mips/pmc-sierra/msp71xx/gpio_extended.c
@@ -0,0 +1,148 @@
+/*
+ * @file /arch/mips/pmc-sierra/msp71xx/gpio_extended.c
+ *
+ * Generic PMC MSP71xx EXTENDED (EXD) GPIO handling. The extended gpio is
+ * a set of hardware registers that have no need for explicit locking as
+ * it is handled by unique method of writing individual set/clr bits.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * @author Patrick Glass <patrickglass@gmail.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+
+#define MSP71XX_DATA_OFFSET(gpio)       (2 * (gpio))
+#define MSP71XX_READ_OFFSET(gpio)       (MSP71XX_DATA_OFFSET(gpio) + 1)
+#define MSP71XX_CFG_OUT_OFFSET(gpio)    (MSP71XX_DATA_OFFSET(gpio) + 16)
+#define MSP71XX_CFG_IN_OFFSET(gpio)     (MSP71XX_CFG_OUT_OFFSET(gpio) + 1)
+
+#define MSP71XX_EXD_GPIO_BASE   0x0BC000000L
+
+#define to_msp71xx_exd_gpio_chip(c) \
+                        container_of(c, struct msp71xx_exd_gpio_chip, chip)
+
+/*
+ * struct msp71xx_exd_gpio_chip - container for gpio chip and registers
+ * @chip: chip structure for the specified gpio bank
+ * @reg: register for control and data of gpio pin
+ */
+struct msp71xx_exd_gpio_chip {
+        struct gpio_chip chip;
+        void __iomem *reg;
+};
+
+/*
+ * msp71xx_exd_gpio_get() - return the chip's gpio value
+ * @chip: chip structure which controls the specified gpio
+ * @offset: gpio whose value will be returned
+ *
+ * It will return 0 if gpio value is low and other if high.
+ */
+static int msp71xx_exd_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+        struct msp71xx_exd_gpio_chip *msp71xx_chip =
+            to_msp71xx_exd_gpio_chip(chip);
+        const unsigned bit = MSP71XX_READ_OFFSET(offset);
+
+        return __raw_readl(msp71xx_chip->reg) & (1 << bit);
+}
+
+/*
+ * msp71xx_exd_gpio_set() - set the output value for the gpio
+ * @chip: chip structure who controls the specified gpio
+ * @offset: gpio whose value will be assigned
+ * @value: logic level to assign to the gpio initially
+ *
+ * This will set the gpio bit specified to the desired value. It will set the
+ * gpio pin low if value is 0 otherwise it will be high.
+ */
+static void msp71xx_exd_gpio_set(struct gpio_chip *chip,
+                                 unsigned offset, int value)
+{
+        struct msp71xx_exd_gpio_chip *msp71xx_chip =
+            to_msp71xx_exd_gpio_chip(chip);
+        const unsigned bit = MSP71XX_DATA_OFFSET(offset);
+
+        __raw_writel(1 << (bit + (value ? 1 : 0)), msp71xx_chip->reg);
+}
+
+/*
+ * msp71xx_exd_direction_output() - declare the direction mode for a gpio
+ * @chip: chip structure which controls the specified gpio
+ * @offset: gpio whose value will be assigned
+ * @value: logic level to assign to the gpio initially
+ *
+ * This call will set the mode for the @gpio to output. It will set the
+ * gpio pin low if value is 0 otherwise it will be high.
+ */
+static int msp71xx_exd_direction_output(struct gpio_chip *chip,
+                                        unsigned offset, int value)
+{
+        struct msp71xx_exd_gpio_chip *msp71xx_chip =
+            to_msp71xx_exd_gpio_chip(chip);
+
+        msp71xx_exd_gpio_set(chip, offset, value);
+        __raw_writel(1 << MSP71XX_CFG_OUT_OFFSET(offset), msp71xx_chip->reg);
+        return 0;
+}
+
+/*
+ * msp71xx_exd_direction_input() - declare the direction mode for a gpio
+ * @chip: chip structure which controls the specified gpio
+ * @offset: gpio whose to which the value will be assigned
+ *
+ * This call will set the mode for the @gpio to input.
+ */
+static int msp71xx_exd_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+        struct msp71xx_exd_gpio_chip *msp71xx_chip =
+            to_msp71xx_exd_gpio_chip(chip);
+
+        __raw_writel(1 << MSP71XX_CFG_IN_OFFSET(offset), msp71xx_chip->reg);
+        return 0;
+}
+
+#define MSP71XX_EXD_GPIO_BANK(name, exd_reg, base_gpio, num_gpio) \
+{ \
+        .chip = { \
+                .label            = name, \
+                .direction_input  = msp71xx_exd_direction_input, \
+                .direction_output = msp71xx_exd_direction_output, \
+                .get              = msp71xx_exd_gpio_get, \
+                .set              = msp71xx_exd_gpio_set, \
+                .base             = base_gpio, \
+                .ngpio            = num_gpio, \
+        }, \
+        .reg    = (void __iomem *)(MSP71XX_EXD_GPIO_BASE + exd_reg), \
+}
+
+/*
+ * struct msp71xx_exd_gpio_banks[] - container array of gpio banks
+ * @chip: chip structure for the specified gpio bank
+ * @reg: register for reading and writing the gpio pin value
+ *
+ * This array structure defines the extended gpio banks for the
+ * PMC MIPS Processor. We specify the bank name, the data/config
+ * register,the base starting gpio number, and the number of
+ * gpios exposed by the bank of gpios.
+ */
+static struct msp71xx_exd_gpio_chip msp71xx_exd_gpio_banks[] = {
+
+        MSP71XX_EXD_GPIO_BANK("GPIO_23_16", 0x188, 16, 8),
+        MSP71XX_EXD_GPIO_BANK("GPIO_27_24", 0x18C, 24, 4),
+};
+
+void __init msp71xx_init_gpio_extended(void)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(msp71xx_exd_gpio_banks); i++)
+                gpiochip_add(&msp71xx_exd_gpio_banks[i].chip);
+}