Hi Stephen.
On Friday, 25 September 2015, Stephen Warren swarren@wwwdotorg.org wrote:
From: Stephen Warren swarren@nvidia.com
In order to make it clear what the parameters to set_config() and set_direction() mean, and similarly for the return values from the respective get_*(), define named constants for these values.
Disassembly shows no diff in the generated code, except that the order of the code in the branches of tegra_gpio_get_function() gets modified without affecting behaviour.
Suggested-by: Tom Warren twarren@nvidia.com Signed-off-by: Stephen Warren swarren@nvidia.com
drivers/gpio/tegra_gpio.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-)
diff --git a/drivers/gpio/tegra_gpio.c b/drivers/gpio/tegra_gpio.c index f9c06fe88b71..8e880e276f0a 100644 --- a/drivers/gpio/tegra_gpio.c +++ b/drivers/gpio/tegra_gpio.c @@ -1,6 +1,6 @@ /*
- NVIDIA Tegra20 GPIO handling.
- (C) Copyright 2010-2012
- (C) Copyright 2010-2012,2015
- NVIDIA Corporation <www.nvidia.com>
- SPDX-License-Identifier: GPL-2.0+
@@ -25,6 +25,11 @@
DECLARE_GLOBAL_DATA_PTR;
+static const int CONFIG_SFIO = 0; +static const int CONFIG_GPIO = 1; +static const int DIRECTION_INPUT = 0; +static const int DIRECTION_OUTPUT = 1;
Why not use an enum?
struct tegra_gpio_platdata { struct gpio_ctlr_bank *bank; const char *port_name; /* Name of port, e.g. "B" */ @@ -37,7 +42,7 @@ struct tegra_port_info { int base_gpio; /* Port number for this port (0, 1,.., n-1) */ };
-/* Return config of pin 'gpio' as GPIO (1) or SFPIO (0) */ +/* Return config of pin 'gpio' as GPIO (1) or SFIO (0) */ static int get_config(unsigned gpio) { struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; @@ -46,15 +51,15 @@ static int get_config(unsigned gpio) int type;
u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
type = (u >> GPIO_BIT(gpio)) & 1;
type = (u >> GPIO_BIT(gpio)) & 1; debug("get_config: port = %d, bit = %d is %s\n", GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
return type;
return type ? CONFIG_GPIO : CONFIG_SFIO;}
-/* Config pin 'gpio' as GPIO or SFPIO, based on 'type' */ +/* Config pin 'gpio' as GPIO or SFIO, based on 'type' */ static void set_config(unsigned gpio, int type) { struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE; @@ -65,7 +70,7 @@ static void set_config(unsigned gpio, int type) GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
if (type) /* GPIO */
if (type != CONFIG_SFIO) u |= 1 << GPIO_BIT(gpio); else u &= ~(1 << GPIO_BIT(gpio));@@ -86,7 +91,7 @@ static int get_direction(unsigned gpio) debug("get_direction: port = %d, bit = %d, %s\n", GPIO_FULLPORT(gpio), GPIO_BIT(gpio), dir ? "OUT" : "IN");
return dir;
return dir ? DIRECTION_OUTPUT : DIRECTION_INPUT;}
/* Config GPIO pin 'gpio' as input or output (OE) as per 'output' */ @@ -100,7 +105,7 @@ static void set_direction(unsigned gpio, int output) GPIO_FULLPORT(gpio), GPIO_BIT(gpio), output ? "OUT" : "IN");
u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]);
if (output)
if (output != DIRECTION_INPUT) u |= 1 << GPIO_BIT(gpio); else u &= ~(1 << GPIO_BIT(gpio));@@ -135,7 +140,7 @@ static int tegra_gpio_direction_input(struct udevice *dev, unsigned offset) struct tegra_port_info *state = dev_get_priv(dev);
/* Configure GPIO direction as input. */
set_direction(state->base_gpio + offset, 0);
set_direction(state->base_gpio + offset, DIRECTION_INPUT); /* Enable the pin as a GPIO */ set_config(state->base_gpio + offset, 1);@@ -154,7 +159,7 @@ static int tegra_gpio_direction_output(struct udevice *dev, unsigned offset, set_level(gpio, value);
/* Configure GPIO direction as output. */
set_direction(gpio, 1);
set_direction(gpio, DIRECTION_OUTPUT); /* Enable the pin as a GPIO */ set_config(state->base_gpio + offset, 1);@@ -199,18 +204,18 @@ void gpio_config_table(const struct tegra_gpio_config *config, int len) for (i = 0; i < len; i++) { switch (config[i].init) { case TEGRA_GPIO_INIT_IN:
set_direction(config[i].gpio, 0);
set_direction(config[i].gpio, DIRECTION_INPUT); break; case TEGRA_GPIO_INIT_OUT0: set_level(config[i].gpio, 0);
set_direction(config[i].gpio, 1);
set_direction(config[i].gpio, DIRECTION_OUTPUT); break; case TEGRA_GPIO_INIT_OUT1: set_level(config[i].gpio, 1);
set_direction(config[i].gpio, 1);
set_direction(config[i].gpio, DIRECTION_OUTPUT); break; }
set_config(config[i].gpio, 1);
set_config(config[i].gpio, CONFIG_GPIO); }}
-- 1.9.1
Regards, Simon