diff options
| author |   Geert Uytterhoeven <geert+renesas@glider.be> | 2021-01-08 11:20:25 +0100 |
|---|---|---|
| committer |   Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2021-02-15 11:43:27 +0100 |
| commit | ecba1eaa7906b0ce864e7eee27ea6cf5d6844e8a (patch) | |
| tree | c574a0d51ddb6de3ba093bdad02c9b6d19701b72 | |
| parent | dt-bindings: gpio: rcar: Add r8a779a0 support (diff) | |
| download | linux-dev-ecba1eaa7906b0ce864e7eee27ea6cf5d6844e8a.tar.xz linux-dev-ecba1eaa7906b0ce864e7eee27ea6cf5d6844e8a.zip | |
gpio: rcar: Optimize GPIO pin state read on R-Car Gen3
Currently, the R-Car GPIO driver treats R-Car Gen2 and R-Car Gen3 GPIO
controllers the same. However, there exist small differences, like the
behavior of the General Input Register (INDT):
- On R-Car Gen1, R-Car Gen2, and RZ/G1, INDT only reflects the state
of an input pin if the GPIO is configured for input,
- On R-Car Gen3 and RZ/G2, INDT always reflects the state of the input
pins.
Hence to accommodate all variants, the driver does not use the INDT
register to read the status of a GPIO line when configured for output,
at the expense of doing 2 or 3 register reads instead of 1.
Given register accesses are slow, change the .get() and .get_multiple()
callbacks to always use INDT to read pin state on SoCs where this is
supported.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
| -rw-r--r-- | drivers/gpio/gpio-rcar.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c index f3b8c4b44cab..edded6478792 100644 --- a/drivers/gpio/gpio-rcar.c +++ b/drivers/gpio/gpio-rcar.c @@ -35,6 +35,7 @@ struct gpio_rcar_bank_info { struct gpio_rcar_info { bool has_outdtsel; bool has_both_edge_trigger; + bool has_always_in; }; struct gpio_rcar_priv { @@ -302,9 +303,11 @@ static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset) struct gpio_rcar_priv *p = gpiochip_get_data(chip); u32 bit = BIT(offset); - /* testing on r8a7790 shows that INDT does not show correct pin state - * when configured as output, so use OUTDT in case of output pins */ - if (gpio_rcar_read(p, INOUTSEL) & bit) + /* + * Before R-Car Gen3, INDT does not show correct pin state when + * configured as output, so use OUTDT in case of output pins + */ + if (!p->info.has_always_in && (gpio_rcar_read(p, INOUTSEL) & bit)) return !!(gpio_rcar_read(p, OUTDT) & bit); else return !!(gpio_rcar_read(p, INDT) & bit); @@ -324,6 +327,11 @@ static int gpio_rcar_get_multiple(struct gpio_chip *chip, unsigned long *mask, if (!bankmask) return 0; + if (p->info.has_always_in) { + bits[0] = gpio_rcar_read(p, INDT) & bankmask; + return 0; + } + spin_lock_irqsave(&p->lock, flags); outputs = gpio_rcar_read(p, INOUTSEL); m = outputs & bankmask; @@ -383,11 +391,19 @@ static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset, static const struct gpio_rcar_info gpio_rcar_info_gen1 = { .has_outdtsel = false, .has_both_edge_trigger = false, + .has_always_in = false, }; static const struct gpio_rcar_info gpio_rcar_info_gen2 = { .has_outdtsel = true, .has_both_edge_trigger = true, + .has_always_in = false, +}; + +static const struct gpio_rcar_info gpio_rcar_info_gen3 = { + .has_outdtsel = true, + .has_both_edge_trigger = true, + .has_always_in = true, }; static const struct of_device_id gpio_rcar_of_table[] = { @@ -399,8 +415,7 @@ static const struct of_device_id gpio_rcar_of_table[] = { .data = &gpio_rcar_info_gen2, }, { .compatible = "renesas,rcar-gen3-gpio", - /* Gen3 GPIO is identical to Gen2. */ - .data = &gpio_rcar_info_gen2, + .data = &gpio_rcar_info_gen3, }, { .compatible = "renesas,gpio-rcar", .data = &gpio_rcar_info_gen1, |