diff options
Diffstat (limited to 'drivers/power/reset/ltc2952-poweroff.c')
| -rw-r--r-- | drivers/power/reset/ltc2952-poweroff.c | 290 |
1 files changed, 121 insertions, 169 deletions
diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c index 34f38a3dc3ff..7ef193b6f7fe 100644 --- a/drivers/power/reset/ltc2952-poweroff.c +++ b/drivers/power/reset/ltc2952-poweroff.c @@ -32,7 +32,9 @@ * - trigger (input) * A level change indicates the shut-down trigger. If it's state reverts * within the time-out defined by trigger_delay, the shut down is not - * executed. + * executed. If no pin is assigned to this input, the driver will start the + * watchdog toggle immediately. The chip will only power off the system if + * it is requested to do so through the kill line. * * - watchdog (output) * Once a shut down is triggered, the driver will toggle this signal, @@ -63,7 +65,7 @@ #include <linux/gpio/consumer.h> #include <linux/reboot.h> -struct ltc2952_poweroff_data { +struct ltc2952_poweroff { struct hrtimer timer_trigger; struct hrtimer timer_wde; @@ -72,22 +74,21 @@ struct ltc2952_poweroff_data { struct device *dev; - unsigned int virq; + struct gpio_desc *gpio_trigger; + struct gpio_desc *gpio_watchdog; + struct gpio_desc *gpio_kill; - /** - * 0: trigger - * 1: watchdog - * 2: kill - */ - struct gpio_desc *gpio[3]; + bool kernel_panic; + struct notifier_block panic_notifier; }; -static int ltc2952_poweroff_panic; -static struct ltc2952_poweroff_data *ltc2952_data; +#define to_ltc2952(p, m) container_of(p, struct ltc2952_poweroff, m) -#define POWERPATH_IO_TRIGGER 0 -#define POWERPATH_IO_WATCHDOG 1 -#define POWERPATH_IO_KILL 2 +/* + * This global variable is only needed for pm_power_off. We should + * remove it entirely once we don't need the global state anymore. + */ +static struct ltc2952_poweroff *ltc2952_data; /** * ltc2952_poweroff_timer_wde - Timer callback @@ -103,29 +104,24 @@ static enum hrtimer_restart ltc2952_poweroff_timer_wde(struct hrtimer *timer) ktime_t now; int state; unsigned long overruns; + struct ltc2952_poweroff *data = to_ltc2952(timer, timer_wde); - if (ltc2952_poweroff_panic) + if (data->kernel_panic) return HRTIMER_NORESTART; - state = gpiod_get_value(ltc2952_data->gpio[POWERPATH_IO_WATCHDOG]); - gpiod_set_value(ltc2952_data->gpio[POWERPATH_IO_WATCHDOG], !state); + state = gpiod_get_value(data->gpio_watchdog); + gpiod_set_value(data->gpio_watchdog, !state); now = hrtimer_cb_get_time(timer); - overruns = hrtimer_forward(timer, now, ltc2952_data->wde_interval); + overruns = hrtimer_forward(timer, now, data->wde_interval); return HRTIMER_RESTART; } -static enum hrtimer_restart ltc2952_poweroff_timer_trigger( - struct hrtimer *timer) +static void ltc2952_poweroff_start_wde(struct ltc2952_poweroff *data) { - int ret; - - ret = hrtimer_start(<c2952_data->timer_wde, - ltc2952_data->wde_interval, HRTIMER_MODE_REL); - - if (ret) { - dev_err(ltc2952_data->dev, "unable to start the timer\n"); + if (hrtimer_start(&data->timer_wde, data->wde_interval, + HRTIMER_MODE_REL)) { /* * The device will not toggle the watchdog reset, * thus shut down is only safe if the PowerPath controller @@ -134,10 +130,17 @@ static enum hrtimer_restart ltc2952_poweroff_timer_trigger( * * Only sending a warning as the system will power-off anyway */ + dev_err(data->dev, "unable to start the timer\n"); } +} - dev_info(ltc2952_data->dev, "executing shutdown\n"); +static enum hrtimer_restart +ltc2952_poweroff_timer_trigger(struct hrtimer *timer) +{ + struct ltc2952_poweroff *data = to_ltc2952(timer, timer_trigger); + ltc2952_poweroff_start_wde(data); + dev_info(data->dev, "executing shutdown\n"); orderly_poweroff(true); return HRTIMER_NORESTART; @@ -154,180 +157,161 @@ static enum hrtimer_restart ltc2952_poweroff_timer_trigger( */ static irqreturn_t ltc2952_poweroff_handler(int irq, void *dev_id) { - int ret; - struct ltc2952_poweroff_data *data = dev_id; + struct ltc2952_poweroff *data = dev_id; - if (ltc2952_poweroff_panic) - goto irq_ok; - - if (hrtimer_active(&data->timer_wde)) { + if (data->kernel_panic || hrtimer_active(&data->timer_wde)) { /* shutdown is already triggered, nothing to do any more */ - goto irq_ok; + return IRQ_HANDLED; } - if (!hrtimer_active(&data->timer_trigger)) { - ret = hrtimer_start(&data->timer_trigger, data->trigger_delay, - HRTIMER_MODE_REL); - - if (ret) + if (gpiod_get_value(data->gpio_trigger)) { + if (hrtimer_start(&data->timer_trigger, data->trigger_delay, + HRTIMER_MODE_REL)) dev_err(data->dev, "unable to start the wait timer\n"); } else { - ret = hrtimer_cancel(&data->timer_trigger); + hrtimer_cancel(&data->timer_trigger); /* omitting return value check, timer should have been valid */ } - -irq_ok: return IRQ_HANDLED; } static void ltc2952_poweroff_kill(void) { - gpiod_set_value(ltc2952_data->gpio[POWERPATH_IO_KILL], 1); -} - -static int ltc2952_poweroff_suspend(struct platform_device *pdev, - pm_message_t state) -{ - return -ENOSYS; -} - -static int ltc2952_poweroff_resume(struct platform_device *pdev) -{ - return -ENOSYS; + gpiod_set_value(ltc2952_data->gpio_kill, 1); } -static void ltc2952_poweroff_default(struct ltc2952_poweroff_data *data) +static void ltc2952_poweroff_default(struct ltc2952_poweroff *data) { - unsigned int i; - - for (i = 0; i < ARRAY_SIZE(data->gpio); i++) - data->gpio[i] = NULL; - data->wde_interval = ktime_set(0, 300L*1E6L); data->trigger_delay = ktime_set(2, 500L*1E6L); hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - data->timer_trigger.function = <c2952_poweroff_timer_trigger; + data->timer_trigger.function = ltc2952_poweroff_timer_trigger; hrtimer_init(&data->timer_wde, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - data->timer_wde.function = <c2952_poweroff_timer_wde; + data->timer_wde.function = ltc2952_poweroff_timer_wde; } static int ltc2952_poweroff_init(struct platform_device *pdev) { - int ret, virq; - unsigned int i; - struct ltc2952_poweroff_data *data; - - static char *name[] = { - "trigger", - "watchdog", - "kill", - NULL - }; - - data = ltc2952_data; - ltc2952_poweroff_default(ltc2952_data); - - for (i = 0; i < ARRAY_SIZE(ltc2952_data->gpio); i++) { - ltc2952_data->gpio[i] = gpiod_get(&pdev->dev, name[i]); + int ret; + struct ltc2952_poweroff *data = platform_get_drvdata(pdev); - if (IS_ERR(ltc2952_data->gpio[i])) { - ret = PTR_ERR(ltc2952_data->gpio[i]); - dev_err(&pdev->dev, - "unable to claim the following gpio: %s\n", - name[i]); - goto err_io; - } - } + ltc2952_poweroff_default(data); - ret = gpiod_direction_output( - ltc2952_data->gpio[POWERPATH_IO_WATCHDOG], 0); - if (ret) { - dev_err(&pdev->dev, "unable to use watchdog-gpio as output\n"); - goto err_io; + data->gpio_watchdog = devm_gpiod_get(&pdev->dev, "watchdog", + GPIOD_OUT_LOW); + if (IS_ERR(data->gpio_watchdog)) { + ret = PTR_ERR(data->gpio_watchdog); + dev_err(&pdev->dev, "unable to claim gpio \"watchdog\"\n"); + return ret; } - ret = gpiod_direction_output(ltc2952_data->gpio[POWERPATH_IO_KILL], 0); - if (ret) { - dev_err(&pdev->dev, "unable to use kill-gpio as output\n"); - goto err_io; + data->gpio_kill = devm_gpiod_get(&pdev->dev, "kill", GPIOD_OUT_LOW); + if (IS_ERR(data->gpio_kill)) { + ret = PTR_ERR(data->gpio_kill); + dev_err(&pdev->dev, "unable to claim gpio \"kill\"\n"); + return ret; } - virq = gpiod_to_irq(ltc2952_data->gpio[POWERPATH_IO_TRIGGER]); - if (virq < 0) { - dev_err(&pdev->dev, "cannot map GPIO as interrupt"); - goto err_io; + data->gpio_trigger = devm_gpiod_get(&pdev->dev, "trigger", GPIOD_IN); + if (IS_ERR(data->gpio_trigger)) { + /* + * It's not a problem if the trigger gpio isn't available, but + * it is worth a warning if its use was defined in the device + * tree. + */ + if (PTR_ERR(data->gpio_trigger) != -ENOENT) + dev_err(&pdev->dev, + "unable to claim gpio \"trigger\"\n"); + data->gpio_trigger = NULL; } - ltc2952_data->virq = virq; - ret = request_irq(virq, - ltc2952_poweroff_handler, - (IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING), - "ltc2952-poweroff", - ltc2952_data - ); - - if (ret) { - dev_err(&pdev->dev, "cannot configure an interrupt handler\n"); - goto err_io; + if (devm_request_irq(&pdev->dev, gpiod_to_irq(data->gpio_trigger), + ltc2952_poweroff_handler, + (IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING), + "ltc2952-poweroff", + data)) { + /* + * Some things may have happened: + * - No trigger input was defined + * - Claiming the GPIO failed + * - We could not map to an IRQ + * - We couldn't register an interrupt handler + * + * None of these really are problems, but all of them + * disqualify the push button from controlling the power. + * + * It is therefore important to note that if the ltc2952 + * detects a button press for long enough, it will still start + * its own powerdown window and cut the power on us if we don't + * start the watchdog trigger. + */ + if (data->gpio_trigger) { + dev_warn(&pdev->dev, + "unable to configure the trigger interrupt\n"); + devm_gpiod_put(&pdev->dev, data->gpio_trigger); + data->gpio_trigger = NULL; + } + dev_info(&pdev->dev, + "power down trigger input will not be used\n"); + ltc2952_poweroff_start_wde(data); } return 0; +} -err_io: - for (i = 0; i < ARRAY_SIZE(ltc2952_data->gpio); i++) - if (ltc2952_data->gpio[i]) - gpiod_put(ltc2952_data->gpio[i]); +static int ltc2952_poweroff_notify_panic(struct notifier_block *nb, + unsigned long code, void *unused) +{ + struct ltc2952_poweroff *data = to_ltc2952(nb, panic_notifier); - return ret; + data->kernel_panic = true; + return NOTIFY_DONE; } static int ltc2952_poweroff_probe(struct platform_device *pdev) { int ret; + struct ltc2952_poweroff *data; if (pm_power_off) { dev_err(&pdev->dev, "pm_power_off already registered"); return -EBUSY; } - ltc2952_data = kzalloc(sizeof(*ltc2952_data), GFP_KERNEL); - if (!ltc2952_data) + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) return -ENOMEM; - ltc2952_data->dev = &pdev->dev; + data->dev = &pdev->dev; + platform_set_drvdata(pdev, data); ret = ltc2952_poweroff_init(pdev); if (ret) - goto err; + return ret; - pm_power_off = <c2952_poweroff_kill; + /* TODO: remove ltc2952_data */ + ltc2952_data = data; + pm_power_off = ltc2952_poweroff_kill; + data->panic_notifier.notifier_call = ltc2952_poweroff_notify_panic; + atomic_notifier_chain_register(&panic_notifier_list, + &data->panic_notifier); dev_info(&pdev->dev, "probe successful\n"); return 0; - -err: - kfree(ltc2952_data); - return ret; } static int ltc2952_poweroff_remove(struct platform_device *pdev) { - unsigned int i; + struct ltc2952_poweroff *data = platform_get_drvdata(pdev); pm_power_off = NULL; - - if (ltc2952_data) { - free_irq(ltc2952_data->virq, ltc2952_data); - - for (i = 0; i < ARRAY_SIZE(ltc2952_data->gpio); i++) - gpiod_put(ltc2952_data->gpio[i]); - - kfree(ltc2952_data); - } - + hrtimer_cancel(&data->timer_trigger); + hrtimer_cancel(&data->timer_wde); + atomic_notifier_chain_unregister(&panic_notifier_list, + &data->panic_notifier); return 0; } @@ -344,41 +328,9 @@ static struct platform_driver ltc2952_poweroff_driver = { .name = "ltc2952-poweroff", .of_match_table = of_ltc2952_poweroff_match, }, - .suspend = ltc2952_poweroff_suspend, - .resume = ltc2952_poweroff_resume, -}; - -static int ltc2952_poweroff_notify_panic(struct notifier_block *nb, - unsigned long code, void *unused) -{ - ltc2952_poweroff_panic = 1; - return NOTIFY_DONE; -} - -static struct notifier_block ltc2952_poweroff_panic_nb = { - .notifier_call = ltc2952_poweroff_notify_panic, }; -static int __init ltc2952_poweroff_platform_init(void) -{ - ltc2952_poweroff_panic = 0; - - atomic_notifier_chain_register(&panic_notifier_list, - <c2952_poweroff_panic_nb); - - return platform_driver_register(<c2952_poweroff_driver); -} - -static void __exit ltc2952_poweroff_platform_exit(void) -{ - atomic_notifier_chain_unregister(&panic_notifier_list, - <c2952_poweroff_panic_nb); - - platform_driver_unregister(<c2952_poweroff_driver); -} - -module_init(ltc2952_poweroff_platform_init); -module_exit(ltc2952_poweroff_platform_exit); +module_platform_driver(ltc2952_poweroff_driver); MODULE_AUTHOR("René Moll <rene.moll@xsens.com>"); MODULE_DESCRIPTION("LTC PowerPath power-off driver"); |