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Diffstat (limited to 'arch/mips/pmcs-msp71xx/gpio_extended.c')
-rw-r--r--arch/mips/pmcs-msp71xx/gpio_extended.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/arch/mips/pmcs-msp71xx/gpio_extended.c b/arch/mips/pmcs-msp71xx/gpio_extended.c
new file mode 100644
index 00000000000..2a99f360fae
--- /dev/null
+++ b/arch/mips/pmcs-msp71xx/gpio_extended.c
@@ -0,0 +1,146 @@
+/*
+ * 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);
+}