From 7bf0d7f62282fa315949106275ff5ed295aefac2 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Fri, 30 Mar 2018 15:02:37 +0800 Subject: [PATCH] gpio: eic: Add edge trigger emulation for EIC The Spreadtrum debounce EIC and latch EIC can not support edge trigger, but most GPIO users (like gpio-key driver) only use the edge trigger, thus the EIC driver need add some support to emulate the edge trigger to satisfy this requirement. Signed-off-by: Baolin Wang Signed-off-by: Linus Walleij --- drivers/gpio/gpio-eic-sprd.c | 73 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) diff --git a/drivers/gpio/gpio-eic-sprd.c b/drivers/gpio/gpio-eic-sprd.c index de7dd939c043..e0d6a0a7bc69 100644 --- a/drivers/gpio/gpio-eic-sprd.c +++ b/drivers/gpio/gpio-eic-sprd.c @@ -300,6 +300,7 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) struct gpio_chip *chip = irq_data_get_irq_chip_data(data); struct sprd_eic *sprd_eic = gpiochip_get_data(chip); u32 offset = irqd_to_hwirq(data); + int state; switch (sprd_eic->type) { case SPRD_EIC_DEBOUNCE: @@ -310,6 +311,17 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) case IRQ_TYPE_LEVEL_LOW: sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0); break; + case IRQ_TYPE_EDGE_RISING: + case IRQ_TYPE_EDGE_FALLING: + case IRQ_TYPE_EDGE_BOTH: + state = sprd_eic_get(chip, offset); + if (state) + sprd_eic_update(chip, offset, + SPRD_EIC_DBNC_IEV, 0); + else + sprd_eic_update(chip, offset, + SPRD_EIC_DBNC_IEV, 1); + break; default: return -ENOTSUPP; } @@ -324,6 +336,17 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) case IRQ_TYPE_LEVEL_LOW: sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1); break; + case IRQ_TYPE_EDGE_RISING: + case IRQ_TYPE_EDGE_FALLING: + case IRQ_TYPE_EDGE_BOTH: + state = sprd_eic_get(chip, offset); + if (state) + sprd_eic_update(chip, offset, + SPRD_EIC_LATCH_INTPOL, 0); + else + sprd_eic_update(chip, offset, + SPRD_EIC_LATCH_INTPOL, 1); + break; default: return -ENOTSUPP; } @@ -405,6 +428,55 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) return 0; } +static void sprd_eic_toggle_trigger(struct gpio_chip *chip, unsigned int irq, + unsigned int offset) +{ + struct sprd_eic *sprd_eic = gpiochip_get_data(chip); + struct irq_data *data = irq_get_irq_data(irq); + u32 trigger = irqd_get_trigger_type(data); + int state, post_state; + + /* + * The debounce EIC and latch EIC can only support level trigger, so we + * can toggle the level trigger to emulate the edge trigger. + */ + if ((sprd_eic->type != SPRD_EIC_DEBOUNCE && + sprd_eic->type != SPRD_EIC_LATCH) || + !(trigger & IRQ_TYPE_EDGE_BOTH)) + return; + + sprd_eic_irq_mask(data); + state = sprd_eic_get(chip, offset); + +retry: + switch (sprd_eic->type) { + case SPRD_EIC_DEBOUNCE: + if (state) + sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0); + else + sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1); + break; + case SPRD_EIC_LATCH: + if (state) + sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0); + else + sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1); + break; + default: + sprd_eic_irq_unmask(data); + return; + } + + post_state = sprd_eic_get(chip, offset); + if (state != post_state) { + dev_warn(chip->parent, "EIC level was changed.\n"); + state = post_state; + goto retry; + } + + sprd_eic_irq_unmask(data); +} + static int sprd_eic_match_chip_by_type(struct gpio_chip *chip, void *data) { enum sprd_eic_type type = *(enum sprd_eic_type *)data; @@ -448,6 +520,7 @@ static void sprd_eic_handle_one_type(struct gpio_chip *chip) bank * SPRD_EIC_PER_BANK_NR + n); generic_handle_irq(girq); + sprd_eic_toggle_trigger(chip, girq, n); } } } -- 2.11.0