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Diffstat (limited to '')
| -rw-r--r-- | drivers/arm/pl061/pl061_gpio.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/arm/pl061/pl061_gpio.c b/drivers/arm/pl061/pl061_gpio.c new file mode 100644 index 0000000..97013e8 --- /dev/null +++ b/drivers/arm/pl061/pl061_gpio.c @@ -0,0 +1,142 @@ +/* + * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + * + * ARM PL061 GPIO Driver. + * Reference to ARM DDI 0190B document. + * + */ + +#include <assert.h> +#include <errno.h> + +#include <common/debug.h> +#include <drivers/arm/pl061_gpio.h> +#include <drivers/gpio.h> +#include <lib/cassert.h> +#include <lib/mmio.h> +#include <lib/utils.h> + +#if !PLAT_PL061_MAX_GPIOS +# define PLAT_PL061_MAX_GPIOS 32 +#endif /* PLAT_PL061_MAX_GPIOS */ + +CASSERT(PLAT_PL061_MAX_GPIOS > 0, assert_plat_pl061_max_gpios); + +#define MAX_GPIO_DEVICES ((PLAT_PL061_MAX_GPIOS + \ + (GPIOS_PER_PL061 - 1)) / GPIOS_PER_PL061) + +#define PL061_GPIO_DIR 0x400 + +#define GPIOS_PER_PL061 8 + +static int pl061_get_direction(int gpio); +static void pl061_set_direction(int gpio, int direction); +static int pl061_get_value(int gpio); +static void pl061_set_value(int gpio, int value); + +static uintptr_t pl061_reg_base[MAX_GPIO_DEVICES]; + +static const gpio_ops_t pl061_gpio_ops = { + .get_direction = pl061_get_direction, + .set_direction = pl061_set_direction, + .get_value = pl061_get_value, + .set_value = pl061_set_value, +}; + +static int pl061_get_direction(int gpio) +{ + uintptr_t base_addr; + unsigned int data, offset; + + assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS)); + + base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061]; + offset = gpio % GPIOS_PER_PL061; + data = mmio_read_8(base_addr + PL061_GPIO_DIR); + if (data & BIT(offset)) + return GPIO_DIR_OUT; + return GPIO_DIR_IN; +} + +static void pl061_set_direction(int gpio, int direction) +{ + uintptr_t base_addr; + unsigned int data, offset; + + assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS)); + + base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061]; + offset = gpio % GPIOS_PER_PL061; + if (direction == GPIO_DIR_OUT) { + data = mmio_read_8(base_addr + PL061_GPIO_DIR) | BIT(offset); + mmio_write_8(base_addr + PL061_GPIO_DIR, data); + } else { + data = mmio_read_8(base_addr + PL061_GPIO_DIR) & ~BIT(offset); + mmio_write_8(base_addr + PL061_GPIO_DIR, data); + } +} + +/* + * The offset of GPIODATA register is 0. + * The values read from GPIODATA are determined for each bit, by the mask bit + * derived from the address used to access the data register, PADDR[9:2]. + * Bits that are 1 in the address mask cause the corresponding bits in GPIODATA + * to be read, and bits that are 0 in the address mask cause the corresponding + * bits in GPIODATA to be read as 0, regardless of their value. + */ +static int pl061_get_value(int gpio) +{ + uintptr_t base_addr; + unsigned int offset; + + assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS)); + + base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061]; + offset = gpio % GPIOS_PER_PL061; + if (mmio_read_8(base_addr + BIT(offset + 2))) + return GPIO_LEVEL_HIGH; + return GPIO_LEVEL_LOW; +} + +/* + * In order to write GPIODATA, the corresponding bits in the mask, resulting + * from the address bus, PADDR[9:2], must be HIGH. Otherwise the bit values + * remain unchanged by the write. + */ +static void pl061_set_value(int gpio, int value) +{ + uintptr_t base_addr; + int offset; + + assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS)); + + base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061]; + offset = gpio % GPIOS_PER_PL061; + if (value == GPIO_LEVEL_HIGH) + mmio_write_8(base_addr + BIT(offset + 2), BIT(offset)); + else + mmio_write_8(base_addr + BIT(offset + 2), 0); +} + + +/* + * Register the PL061 GPIO controller with a base address and the offset + * of start pin in this GPIO controller. + * This function is called after pl061_gpio_ops_init(). + */ +void pl061_gpio_register(uintptr_t base_addr, int gpio_dev) +{ + assert((gpio_dev >= 0) && (gpio_dev < MAX_GPIO_DEVICES)); + + pl061_reg_base[gpio_dev] = base_addr; +} + +/* + * Initialize PL061 GPIO controller with the total GPIO numbers in SoC. + */ +void pl061_gpio_init(void) +{ + gpio_init(&pl061_gpio_ops); +} |