From 9941e5a5e6d513a39966a129d77bd47925a0f407 Mon Sep 17 00:00:00 2001 From: Maxim Polyakov Date: Sat, 14 Nov 2020 18:42:10 +0300 Subject: [PATCH] ec/kontron/kempld: Add minimal GPIO driver The patch adds an interface for configuring GPIOs inside the Kontron CPLD/EC. This allows to statically define the mode for each GPIO pin in devicetree.cb of the motherboard or carrier board. For example: chip ec/kontron/kempld device gpio 0 on register "gpio[0]" = "KEMPLD_GPIO_INPUT" register "gpio[4]" = "KEMPLD_GPIO_OUTPUT_LOW" register "gpio[5]" = "KEMPLD_GPIO_OUTPUT_HIGH" register "gpio[11]" = "KEMPLD_GPIO_DEFAULT" end end In this case, , like all other devices, is not a real device inside the EC. These definitions are used to understand the EC resources and systematize configuration options, but if mark this as , the initialization step will be skipped in the driver code. Use KEMPLD_GPIO_DEFAULT or skip it in devicetree.cb to not configure the GPIO and keep the default mode after CPLD reset. This work is based on code from the drivers/gpio/gpio-kempld.c linux driver. Tested on Kontron mAL-10 COMe module [1]. [1] CB:54380 , Change-Id: I7d354aa32ac8c64f54b2bcbdb4f1b8915f55264e Change-Id: Id767aa451fbf2ca1c0dccfc9aa2c024c6f37c1bb Signed-off-by: Maxim Polyakov Reviewed-on: https://review.coreboot.org/c/coreboot/+/47595 Reviewed-by: Nico Huber Reviewed-by: Angel Pons Tested-by: build bot (Jenkins) --- src/ec/kontron/kempld/Makefile.inc | 1 + src/ec/kontron/kempld/chip.h | 11 +++- src/ec/kontron/kempld/kempld.c | 8 +++ src/ec/kontron/kempld/kempld_gpio.c | 71 +++++++++++++++++++++++++ src/ec/kontron/kempld/kempld_internal.h | 5 ++ 5 files changed, 95 insertions(+), 1 deletion(-) create mode 100644 src/ec/kontron/kempld/kempld_gpio.c diff --git a/src/ec/kontron/kempld/Makefile.inc b/src/ec/kontron/kempld/Makefile.inc index 0d5988625e..e7bafa39e7 100644 --- a/src/ec/kontron/kempld/Makefile.inc +++ b/src/ec/kontron/kempld/Makefile.inc @@ -2,3 +2,4 @@ bootblock-$(CONFIG_EC_KONTRON_KEMPLD) += early_kempld.c ramstage-$(CONFIG_EC_KONTRON_KEMPLD) += early_kempld.c ramstage-$(CONFIG_EC_KONTRON_KEMPLD) += kempld.c ramstage-$(CONFIG_EC_KONTRON_KEMPLD) += kempld_i2c.c +ramstage-$(CONFIG_EC_KONTRON_KEMPLD) += kempld_gpio.c diff --git a/src/ec/kontron/kempld/chip.h b/src/ec/kontron/kempld/chip.h index 30f40fe097..c44a103182 100644 --- a/src/ec/kontron/kempld/chip.h +++ b/src/ec/kontron/kempld/chip.h @@ -3,7 +3,15 @@ #ifndef EC_KONTRON_KEMPLD_CHIP_H #define EC_KONTRON_KEMPLD_CHIP_H -#define KEMPLD_NUM_UARTS 2 +#define KEMPLD_NUM_UARTS 2 +#define KEMPLD_NUM_GPIOS 16 + +enum kempld_gpio_mode { + KEMPLD_GPIO_DEFAULT = 0, + KEMPLD_GPIO_INPUT, + KEMPLD_GPIO_OUTPUT_LOW, + KEMPLD_GPIO_OUTPUT_HIGH, +}; enum kempld_uart_io { KEMPLD_UART_3F8 = 0, @@ -26,6 +34,7 @@ struct kempld_uart { struct ec_kontron_kempld_config { struct kempld_uart uart[KEMPLD_NUM_UARTS]; + enum kempld_gpio_mode gpio[KEMPLD_NUM_GPIOS]; unsigned short i2c_frequency; }; diff --git a/src/ec/kontron/kempld/kempld.c b/src/ec/kontron/kempld/kempld.c index f8371a8d82..0489bac042 100644 --- a/src/ec/kontron/kempld/kempld.c +++ b/src/ec/kontron/kempld/kempld.c @@ -93,6 +93,14 @@ static void kempld_enable_dev(struct device *const dev) printk(BIOS_WARNING, "KEMPLD: Spurious device %s.\n", dev_path(dev)); break; } + } else if (dev->path.type == DEVICE_PATH_GPIO) { + if (dev->path.gpio.id == 0) { + if (kempld_gpio_pads_config(dev) < 0) + printk(BIOS_ERR, "KEMPLD: GPIO configuration failed!\n"); + } else { + printk(BIOS_WARNING, "KEMPLD: Spurious GPIO device %s.\n", + dev_path(dev)); + } } } diff --git a/src/ec/kontron/kempld/kempld_gpio.c b/src/ec/kontron/kempld/kempld_gpio.c new file mode 100644 index 0000000000..8699c1f477 --- /dev/null +++ b/src/ec/kontron/kempld/kempld_gpio.c @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include +#include +#include +#include "chip.h" +#include "kempld.h" +#include "kempld_internal.h" + +enum kempld_gpio_direction { + KEMPLD_GPIO_DIR_IN = 0, + KEMPLD_GPIO_DIR_OUT = 1 +}; + +static void kempld_gpio_value_set(u8 pin_num, u8 value) +{ + const u8 mask = KEMPLD_GPIO_MASK(pin_num); + u8 reg_val = kempld_read8(KEMPLD_GPIO_LVL(pin_num)); + reg_val = value ? reg_val | mask : reg_val & ~mask; + kempld_write8(KEMPLD_GPIO_LVL(pin_num), reg_val); +} + +static void kempld_gpio_direction_set(u8 pin_num, enum kempld_gpio_direction dir) +{ + const u8 mask = KEMPLD_GPIO_MASK(pin_num); + u8 reg_val = kempld_read8(KEMPLD_GPIO_DIR(pin_num)); + reg_val = dir == KEMPLD_GPIO_DIR_OUT ? reg_val | mask : reg_val & ~mask; + kempld_write8(KEMPLD_GPIO_DIR(pin_num), reg_val); +} + +static int kempld_configure_gpio(u8 pin_num, enum kempld_gpio_mode mode) +{ + if (kempld_get_mutex(100) < 0) + return -1; + + switch (mode) { + case KEMPLD_GPIO_DEFAULT: + break; + + case KEMPLD_GPIO_INPUT: + kempld_gpio_direction_set(pin_num, KEMPLD_GPIO_DIR_IN); + break; + + case KEMPLD_GPIO_OUTPUT_LOW: + kempld_gpio_value_set(pin_num, 0); + kempld_gpio_direction_set(pin_num, KEMPLD_GPIO_DIR_OUT); + break; + + case KEMPLD_GPIO_OUTPUT_HIGH: + kempld_gpio_value_set(pin_num, 1); + kempld_gpio_direction_set(pin_num, KEMPLD_GPIO_DIR_OUT); + break; + } + + kempld_release_mutex(); + return 0; +} + +int kempld_gpio_pads_config(struct device *dev) +{ + const struct ec_kontron_kempld_config *config = dev->chip_info; + + if (!config) + return -1; + + for (u8 i = 0; i < KEMPLD_NUM_GPIOS; ++i) { + if (kempld_configure_gpio(i, config->gpio[i]) < 0) + return -1; + } + return 0; +} diff --git a/src/ec/kontron/kempld/kempld_internal.h b/src/ec/kontron/kempld/kempld_internal.h index 993fe8edd1..2c64f7946b 100644 --- a/src/ec/kontron/kempld/kempld_internal.h +++ b/src/ec/kontron/kempld/kempld_internal.h @@ -28,6 +28,11 @@ #define KEMPLD_CLK 33333333 /* 33MHz */ +#define KEMPLD_GPIO_MASK(pin_num) (1 << ((pin_num) % 8)) +#define KEMPLD_GPIO_DIR(pin_num) (0x40 + (pin_num) / 8) +#define KEMPLD_GPIO_LVL(pin_num) (0x42 + (pin_num) / 8) + void kempld_i2c_device_init(struct device *const dev); +int kempld_gpio_pads_config(struct device *dev); #endif /* EC_KONTRON_KEMPLD_INTERNAL_H */