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-rw-r--r--arch/mips/pmcs-msp71xx/gpio.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/arch/mips/pmcs-msp71xx/gpio.c b/arch/mips/pmcs-msp71xx/gpio.c
new file mode 100644
index 0000000..aaccbe5
--- /dev/null
+++ b/arch/mips/pmcs-msp71xx/gpio.c
@@ -0,0 +1,216 @@
+/*
+ * Generic PMC MSP71xx GPIO handling. These base gpio are controlled by two
+ * types of registers. The data register sets the output level when in output
+ * mode and when in input mode will contain the value at the input. The config
+ * register sets the various modes for each gpio.
+ *
+ * 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/spinlock.h>
+#include <linux/io.h>
+
+#define MSP71XX_CFG_OFFSET(gpio) (4 * (gpio))
+#define CONF_MASK 0x0F
+#define MSP71XX_GPIO_INPUT 0x01
+#define MSP71XX_GPIO_OUTPUT 0x08
+
+#define MSP71XX_GPIO_BASE 0x0B8400000L
+
+#define to_msp71xx_gpio_chip(c) container_of(c, struct msp71xx_gpio_chip, chip)
+
+static spinlock_t gpio_lock;
+
+/*
+ * struct msp71xx_gpio_chip - container for gpio chip and registers
+ * @chip: chip structure for the specified gpio bank
+ * @data_reg: register for reading and writing the gpio pin value
+ * @config_reg: register to set the mode for the gpio pin bank
+ * @out_drive_reg: register to set the output drive mode for the gpio pin bank
+ */
+struct msp71xx_gpio_chip {
+ struct gpio_chip chip;
+ void __iomem *data_reg;
+ void __iomem *config_reg;
+ void __iomem *out_drive_reg;
+};
+
+/*
+ * msp71xx_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_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct msp71xx_gpio_chip *msp_chip = to_msp71xx_gpio_chip(chip);
+
+ return __raw_readl(msp_chip->data_reg) & (1 << offset);
+}
+
+/*
+ * msp71xx_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_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct msp71xx_gpio_chip *msp_chip = to_msp71xx_gpio_chip(chip);
+ unsigned long flags;
+ u32 data;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ data = __raw_readl(msp_chip->data_reg);
+ if (value)
+ data |= (1 << offset);
+ else
+ data &= ~(1 << offset);
+ __raw_writel(data, msp_chip->data_reg);
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+}
+
+/*
+ * msp71xx_set_gpio_mode() - declare the mode for a gpio
+ * @chip: chip structure which controls the specified gpio
+ * @offset: gpio whose value will be assigned
+ * @mode: desired configuration for the gpio (see datasheet)
+ *
+ * It will set the gpio pin config to the @mode value passed in.
+ */
+static int msp71xx_set_gpio_mode(struct gpio_chip *chip,
+ unsigned offset, int mode)
+{
+ struct msp71xx_gpio_chip *msp_chip = to_msp71xx_gpio_chip(chip);
+ const unsigned bit_offset = MSP71XX_CFG_OFFSET(offset);
+ unsigned long flags;
+ u32 cfg;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ cfg = __raw_readl(msp_chip->config_reg);
+ cfg &= ~(CONF_MASK << bit_offset);
+ cfg |= (mode << bit_offset);
+ __raw_writel(cfg, msp_chip->config_reg);
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return 0;
+}
+
+/*
+ * msp71xx_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_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ msp71xx_gpio_set(chip, offset, value);
+
+ return msp71xx_set_gpio_mode(chip, offset, MSP71XX_GPIO_OUTPUT);
+}
+
+/*
+ * msp71xx_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_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ return msp71xx_set_gpio_mode(chip, offset, MSP71XX_GPIO_INPUT);
+}
+
+/*
+ * msp71xx_set_output_drive() - declare the output drive for the gpio line
+ * @gpio: gpio pin whose output drive you wish to modify
+ * @value: zero for active drain 1 for open drain drive
+ *
+ * This call will set the output drive mode for the @gpio to output.
+ */
+int msp71xx_set_output_drive(unsigned gpio, int value)
+{
+ unsigned long flags;
+ u32 data;
+
+ if (gpio > 15 || gpio < 0)
+ return -EINVAL;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ data = __raw_readl((void __iomem *)(MSP71XX_GPIO_BASE + 0x190));
+ if (value)
+ data |= (1 << gpio);
+ else
+ data &= ~(1 << gpio);
+ __raw_writel(data, (void __iomem *)(MSP71XX_GPIO_BASE + 0x190));
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(msp71xx_set_output_drive);
+
+#define MSP71XX_GPIO_BANK(name, dr, cr, base_gpio, num_gpio) \
+{ \
+ .chip = { \
+ .label = name, \
+ .direction_input = msp71xx_direction_input, \
+ .direction_output = msp71xx_direction_output, \
+ .get = msp71xx_gpio_get, \
+ .set = msp71xx_gpio_set, \
+ .base = base_gpio, \
+ .ngpio = num_gpio \
+ }, \
+ .data_reg = (void __iomem *)(MSP71XX_GPIO_BASE + dr), \
+ .config_reg = (void __iomem *)(MSP71XX_GPIO_BASE + cr), \
+ .out_drive_reg = (void __iomem *)(MSP71XX_GPIO_BASE + 0x190), \
+}
+
+/*
+ * struct msp71xx_gpio_banks[] - container array of gpio banks
+ * @chip: chip structure for the specified gpio bank
+ * @data_reg: register for reading and writing the gpio pin value
+ * @config_reg: register to set the mode for the gpio pin bank
+ *
+ * This array structure defines the gpio banks for the PMC MIPS Processor.
+ * We specify the bank name, the data register, the config register, base
+ * starting gpio number, and the number of gpios exposed by the bank.
+ */
+static struct msp71xx_gpio_chip msp71xx_gpio_banks[] = {
+
+ MSP71XX_GPIO_BANK("GPIO_1_0", 0x170, 0x180, 0, 2),
+ MSP71XX_GPIO_BANK("GPIO_5_2", 0x174, 0x184, 2, 4),
+ MSP71XX_GPIO_BANK("GPIO_9_6", 0x178, 0x188, 6, 4),
+ MSP71XX_GPIO_BANK("GPIO_15_10", 0x17C, 0x18C, 10, 6),
+};
+
+void __init msp71xx_init_gpio(void)
+{
+ int i;
+
+ spin_lock_init(&gpio_lock);
+
+ for (i = 0; i < ARRAY_SIZE(msp71xx_gpio_banks); i++)
+ gpiochip_add(&msp71xx_gpio_banks[i].chip);
+}
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