diff options
Diffstat (limited to 'arch/arm/mach-ep93xx/gpio.c')
| -rw-r--r-- | arch/arm/mach-ep93xx/gpio.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/arch/arm/mach-ep93xx/gpio.c b/arch/arm/mach-ep93xx/gpio.c new file mode 100644 index 00000000..415dce37 --- /dev/null +++ b/arch/arm/mach-ep93xx/gpio.c @@ -0,0 +1,410 @@ +/* + * linux/arch/arm/mach-ep93xx/gpio.c + * + * Generic EP93xx GPIO handling + * + * Copyright (c) 2008 Ryan Mallon <ryan@bluewatersys.com> + * + * Based on code originally from: + * linux/arch/arm/mach-ep93xx/core.c + * + * 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. + */ + +#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/seq_file.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/irq.h> + +#include <mach/hardware.h> + +/************************************************************************* + * Interrupt handling for EP93xx on-chip GPIOs + *************************************************************************/ +static unsigned char gpio_int_unmasked[3]; +static unsigned char gpio_int_enabled[3]; +static unsigned char gpio_int_type1[3]; +static unsigned char gpio_int_type2[3]; +static unsigned char gpio_int_debounce[3]; + +/* Port ordering is: A B F */ +static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c }; +static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 }; +static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 }; +static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 }; +static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 }; + +static void ep93xx_gpio_update_int_params(unsigned port) +{ + BUG_ON(port > 2); + + __raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port])); + + __raw_writeb(gpio_int_type2[port], + EP93XX_GPIO_REG(int_type2_register_offset[port])); + + __raw_writeb(gpio_int_type1[port], + EP93XX_GPIO_REG(int_type1_register_offset[port])); + + __raw_writeb(gpio_int_unmasked[port] & gpio_int_enabled[port], + EP93XX_GPIO_REG(int_en_register_offset[port])); +} + +static inline void ep93xx_gpio_int_mask(unsigned line) +{ + gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7)); +} + +static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable) +{ + int line = irq_to_gpio(irq); + int port = line >> 3; + int port_mask = 1 << (line & 7); + + if (enable) + gpio_int_debounce[port] |= port_mask; + else + gpio_int_debounce[port] &= ~port_mask; + + __raw_writeb(gpio_int_debounce[port], + EP93XX_GPIO_REG(int_debounce_register_offset[port])); +} + +static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + unsigned char status; + int i; + + status = __raw_readb(EP93XX_GPIO_A_INT_STATUS); + for (i = 0; i < 8; i++) { + if (status & (1 << i)) { + int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i; + generic_handle_irq(gpio_irq); + } + } + + status = __raw_readb(EP93XX_GPIO_B_INT_STATUS); + for (i = 0; i < 8; i++) { + if (status & (1 << i)) { + int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i; + generic_handle_irq(gpio_irq); + } + } +} + +static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + /* + * map discontiguous hw irq range to continuous sw irq range: + * + * IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7}) + */ + int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */ + int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx; + + generic_handle_irq(gpio_irq); +} + +static void ep93xx_gpio_irq_ack(struct irq_data *d) +{ + int line = irq_to_gpio(d->irq); + int port = line >> 3; + int port_mask = 1 << (line & 7); + + if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) { + gpio_int_type2[port] ^= port_mask; /* switch edge direction */ + ep93xx_gpio_update_int_params(port); + } + + __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port])); +} + +static void ep93xx_gpio_irq_mask_ack(struct irq_data *d) +{ + int line = irq_to_gpio(d->irq); + int port = line >> 3; + int port_mask = 1 << (line & 7); + + if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) + gpio_int_type2[port] ^= port_mask; /* switch edge direction */ + + gpio_int_unmasked[port] &= ~port_mask; + ep93xx_gpio_update_int_params(port); + + __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port])); +} + +static void ep93xx_gpio_irq_mask(struct irq_data *d) +{ + int line = irq_to_gpio(d->irq); + int port = line >> 3; + + gpio_int_unmasked[port] &= ~(1 << (line & 7)); + ep93xx_gpio_update_int_params(port); +} + +static void ep93xx_gpio_irq_unmask(struct irq_data *d) +{ + int line = irq_to_gpio(d->irq); + int port = line >> 3; + + gpio_int_unmasked[port] |= 1 << (line & 7); + ep93xx_gpio_update_int_params(port); +} + +/* + * gpio_int_type1 controls whether the interrupt is level (0) or + * edge (1) triggered, while gpio_int_type2 controls whether it + * triggers on low/falling (0) or high/rising (1). + */ +static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type) +{ + const int gpio = irq_to_gpio(d->irq); + const int port = gpio >> 3; + const int port_mask = 1 << (gpio & 7); + irq_flow_handler_t handler; + + gpio_direction_input(gpio); + + switch (type) { + case IRQ_TYPE_EDGE_RISING: + gpio_int_type1[port] |= port_mask; + gpio_int_type2[port] |= port_mask; + handler = handle_edge_irq; + break; + case IRQ_TYPE_EDGE_FALLING: + gpio_int_type1[port] |= port_mask; + gpio_int_type2[port] &= ~port_mask; + handler = handle_edge_irq; + break; + case IRQ_TYPE_LEVEL_HIGH: + gpio_int_type1[port] &= ~port_mask; + gpio_int_type2[port] |= port_mask; + handler = handle_level_irq; + break; + case IRQ_TYPE_LEVEL_LOW: + gpio_int_type1[port] &= ~port_mask; + gpio_int_type2[port] &= ~port_mask; + handler = handle_level_irq; + break; + case IRQ_TYPE_EDGE_BOTH: + gpio_int_type1[port] |= port_mask; + /* set initial polarity based on current input level */ + if (gpio_get_value(gpio)) + gpio_int_type2[port] &= ~port_mask; /* falling */ + else + gpio_int_type2[port] |= port_mask; /* rising */ + handler = handle_edge_irq; + break; + default: + pr_err("failed to set irq type %d for gpio %d\n", type, gpio); + return -EINVAL; + } + + __irq_set_handler_locked(d->irq, handler); + + gpio_int_enabled[port] |= port_mask; + + ep93xx_gpio_update_int_params(port); + + return 0; +} + +static struct irq_chip ep93xx_gpio_irq_chip = { + .name = "GPIO", + .irq_ack = ep93xx_gpio_irq_ack, + .irq_mask_ack = ep93xx_gpio_irq_mask_ack, + .irq_mask = ep93xx_gpio_irq_mask, + .irq_unmask = ep93xx_gpio_irq_unmask, + .irq_set_type = ep93xx_gpio_irq_type, +}; + +void __init ep93xx_gpio_init_irq(void) +{ + int gpio_irq; + + for (gpio_irq = gpio_to_irq(0); + gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) { + irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip, + handle_level_irq); + set_irq_flags(gpio_irq, IRQF_VALID); + } + + irq_set_chained_handler(IRQ_EP93XX_GPIO_AB, + ep93xx_gpio_ab_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX, + ep93xx_gpio_f_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX, + ep93xx_gpio_f_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX, + ep93xx_gpio_f_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX, + ep93xx_gpio_f_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX, + ep93xx_gpio_f_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX, + ep93xx_gpio_f_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX, + ep93xx_gpio_f_irq_handler); + irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX, + ep93xx_gpio_f_irq_handler); +} + + +/************************************************************************* + * gpiolib interface for EP93xx on-chip GPIOs + *************************************************************************/ +struct ep93xx_gpio_chip { + struct gpio_chip chip; + + void __iomem *data_reg; + void __iomem *data_dir_reg; +}; + +#define to_ep93xx_gpio_chip(c) container_of(c, struct ep93xx_gpio_chip, chip) + +static int ep93xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip); + unsigned long flags; + u8 v; + + local_irq_save(flags); + v = __raw_readb(ep93xx_chip->data_dir_reg); + v &= ~(1 << offset); + __raw_writeb(v, ep93xx_chip->data_dir_reg); + local_irq_restore(flags); + + return 0; +} + +static int ep93xx_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int val) +{ + struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip); + unsigned long flags; + int line; + u8 v; + + local_irq_save(flags); + + /* Set the value */ + v = __raw_readb(ep93xx_chip->data_reg); + if (val) + v |= (1 << offset); + else + v &= ~(1 << offset); + __raw_writeb(v, ep93xx_chip->data_reg); + + /* Drive as an output */ + line = chip->base + offset; + if (line <= EP93XX_GPIO_LINE_MAX_IRQ) { + /* Ports A/B/F */ + ep93xx_gpio_int_mask(line); + ep93xx_gpio_update_int_params(line >> 3); + } + + v = __raw_readb(ep93xx_chip->data_dir_reg); + v |= (1 << offset); + __raw_writeb(v, ep93xx_chip->data_dir_reg); + + local_irq_restore(flags); + + return 0; +} + +static int ep93xx_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip); + + return !!(__raw_readb(ep93xx_chip->data_reg) & (1 << offset)); +} + +static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val) +{ + struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip); + unsigned long flags; + u8 v; + + local_irq_save(flags); + v = __raw_readb(ep93xx_chip->data_reg); + if (val) + v |= (1 << offset); + else + v &= ~(1 << offset); + __raw_writeb(v, ep93xx_chip->data_reg); + local_irq_restore(flags); +} + +static int ep93xx_gpio_set_debounce(struct gpio_chip *chip, + unsigned offset, unsigned debounce) +{ + int gpio = chip->base + offset; + int irq = gpio_to_irq(gpio); + + if (irq < 0) + return -EINVAL; + + ep93xx_gpio_int_debounce(irq, debounce ? true : false); + + return 0; +} + +#define EP93XX_GPIO_BANK(name, dr, ddr, base_gpio) \ + { \ + .chip = { \ + .label = name, \ + .direction_input = ep93xx_gpio_direction_input, \ + .direction_output = ep93xx_gpio_direction_output, \ + .get = ep93xx_gpio_get, \ + .set = ep93xx_gpio_set, \ + .base = base_gpio, \ + .ngpio = 8, \ + }, \ + .data_reg = EP93XX_GPIO_REG(dr), \ + .data_dir_reg = EP93XX_GPIO_REG(ddr), \ + } + +static struct ep93xx_gpio_chip ep93xx_gpio_banks[] = { + EP93XX_GPIO_BANK("A", 0x00, 0x10, 0), + EP93XX_GPIO_BANK("B", 0x04, 0x14, 8), + EP93XX_GPIO_BANK("C", 0x08, 0x18, 40), + EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24), + EP93XX_GPIO_BANK("E", 0x20, 0x24, 32), + EP93XX_GPIO_BANK("F", 0x30, 0x34, 16), + EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48), + EP93XX_GPIO_BANK("H", 0x40, 0x44, 56), +}; + +void __init ep93xx_gpio_init(void) +{ + int i; + + /* Set Ports C, D, E, G, and H for GPIO use */ + ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_KEYS | + EP93XX_SYSCON_DEVCFG_GONK | + EP93XX_SYSCON_DEVCFG_EONIDE | + EP93XX_SYSCON_DEVCFG_GONIDE | + EP93XX_SYSCON_DEVCFG_HONIDE); + + for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) { + struct gpio_chip *chip = &ep93xx_gpio_banks[i].chip; + + /* + * Ports A, B, and F support input debouncing when + * used as interrupts. + */ + if (!strcmp(chip->label, "A") || + !strcmp(chip->label, "B") || + !strcmp(chip->label, "F")) + chip->set_debounce = ep93xx_gpio_set_debounce; + + gpiochip_add(chip); + } +} |