diff options
Diffstat (limited to 'chip/lm4/pwm_kblight.c')
| -rw-r--r-- | chip/lm4/pwm_kblight.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/chip/lm4/pwm_kblight.c b/chip/lm4/pwm_kblight.c new file mode 100644 index 0000000000..9382a8e35f --- /dev/null +++ b/chip/lm4/pwm_kblight.c @@ -0,0 +1,190 @@ +/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/* PWM control module for Chromebook keyboard backlight. */ + +#include "clock.h" +#include "common.h" +#include "console.h" +#include "gpio.h" +#include "hooks.h" +#include "host_command.h" +#include "pwm.h" +#include "registers.h" +#include "system.h" +#include "task.h" +#include "thermal.h" +#include "timer.h" +#include "util.h" + +/* Max PWM for controller */ +#define MAX_PWM 0x1ff + +#define PWMKBD_SYSJUMP_TAG 0x504b /* "PK" */ +#define PWM_HOOK_VERSION 1 +/* Saved PWM state across sysjumps */ +struct pwm_kbd_state { + uint8_t kblight_en; + uint8_t kblight_percent; + uint8_t pad0, pad1; /* Pad to multiple of 4 bytes. */ +}; + +/** + * Configure the GPIOs for the pwm module. + */ +static void configure_kblight_gpios(void) +{ + /* HEY: This for Link only */ + /* PK6 alternate function 1 = channel 1 PWM */ + gpio_set_alternate_function(LM4_GPIO_K, 0x40, 1); +} + +void pwm_enable_keyboard_backlight(int enable) +{ + if (enable) + LM4_FAN_FANCTL |= (1 << FAN_CH_KBLIGHT); + else + LM4_FAN_FANCTL &= ~(1 << FAN_CH_KBLIGHT); +} + +int pwm_get_keyboard_backlight_enabled(void) +{ + return (LM4_FAN_FANCTL & (1 << FAN_CH_KBLIGHT)) ? 1 : 0; +} + +int pwm_get_keyboard_backlight(void) +{ + return ((LM4_FAN_FANCMD(FAN_CH_KBLIGHT) >> 16) * 100 + + MAX_PWM / 2) / MAX_PWM; +} + +void pwm_set_keyboard_backlight(int percent) +{ + if (percent < 0) + percent = 0; + else if (percent > 100) + percent = 100; + + LM4_FAN_FANCMD(FAN_CH_KBLIGHT) = ((percent * MAX_PWM + 50) / 100) << 16; +} + +/*****************************************************************************/ +/* Console commands */ + +static int command_kblight(int argc, char **argv) +{ + if (argc >= 2) { + char *e; + int i = strtoi(argv[1], &e, 0); + if (*e) + return EC_ERROR_PARAM1; + pwm_set_keyboard_backlight(i); + } + + ccprintf("Keyboard backlight: %d%%\n", pwm_get_keyboard_backlight()); + return EC_SUCCESS; +} +DECLARE_CONSOLE_COMMAND(kblight, command_kblight, + "percent", + "Set keyboard backlight", + NULL); + +/*****************************************************************************/ +/* Host commands */ + +int pwm_command_get_keyboard_backlight(struct host_cmd_handler_args *args) +{ + struct ec_response_pwm_get_keyboard_backlight *r = args->response; + + r->percent = pwm_get_keyboard_backlight(); + r->enabled = pwm_get_keyboard_backlight_enabled(); + args->response_size = sizeof(*r); + + return EC_RES_SUCCESS; +} +DECLARE_HOST_COMMAND(EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT, + pwm_command_get_keyboard_backlight, + EC_VER_MASK(0)); + +int pwm_command_set_keyboard_backlight(struct host_cmd_handler_args *args) +{ + const struct ec_params_pwm_set_keyboard_backlight *p = args->params; + + pwm_set_keyboard_backlight(p->percent); + + return EC_RES_SUCCESS; +} +DECLARE_HOST_COMMAND(EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT, + pwm_command_set_keyboard_backlight, + EC_VER_MASK(0)); + +/*****************************************************************************/ +/* Hooks */ + +static void pwm_kblight_init(void) +{ + const struct pwm_kbd_state *prev; + int version, size; + + /* Enable the fan module and delay a few clocks */ + LM4_SYSTEM_RCGCFAN = 1; + clock_wait_cycles(3); + + /* Configure GPIOs */ + configure_kblight_gpios(); + + /* Disable all fans */ + LM4_FAN_FANCTL = 0; + + /* + * Configure keyboard backlight: + * 0x0000 = bit 15 = auto-restart + * 0x0000 = bit 14 = slow acceleration + * 0x0000 = bits 13:11 = no hysteresis + * 0x0000 = bits 10:8 = start period (2<<0) edges + * 0x0000 = bits 7:6 = no fast start + * 0x0000 = bits 5:4 = average 4 edges when calculating RPM + * 0x0000 = bits 3:2 = 4 pulses per revolution + * 0x0001 = bit 0 = manual control + */ + LM4_FAN_FANCH(FAN_CH_KBLIGHT) = 0x0001; + + prev = (const struct pwm_kbd_state *) + system_get_jump_tag(PWMKBD_SYSJUMP_TAG, &version, &size); + if (prev && version == PWM_HOOK_VERSION && size == sizeof(*prev)) { + /* Restore previous state. */ + pwm_enable_keyboard_backlight(prev->kblight_en); + pwm_set_keyboard_backlight(prev->kblight_percent); + } else { + /* Enable keyboard backlight control, turned down */ + pwm_set_keyboard_backlight(0); + pwm_enable_keyboard_backlight(1); + } +} +DECLARE_HOOK(HOOK_INIT, pwm_kblight_init, HOOK_PRIO_DEFAULT); + +static void pwm_kblight_preserve_state(void) +{ + struct pwm_kbd_state state; + + state.kblight_en = pwm_get_keyboard_backlight_enabled(); + state.kblight_percent = pwm_get_keyboard_backlight(); + + system_add_jump_tag(PWMKBD_SYSJUMP_TAG, PWM_HOOK_VERSION, + sizeof(state), &state); +} +DECLARE_HOOK(HOOK_SYSJUMP, pwm_kblight_preserve_state, HOOK_PRIO_DEFAULT); + +static void pwm_kblight_suspend(void) +{ + pwm_set_keyboard_backlight(0); +} +DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, pwm_kblight_suspend, HOOK_PRIO_DEFAULT); + +static void pwm_kblight_shutdown(void) +{ + pwm_set_keyboard_backlight(0); +} +DECLARE_HOOK(HOOK_CHIPSET_SHUTDOWN, pwm_kblight_shutdown, HOOK_PRIO_DEFAULT); |