Gitweb: http://git.kernel.org/linus/0fc64cc0a27288e77ee8e12648d59632649371fc
Commit: 0fc64cc0a27288e77ee8e12648d59632649371fc
Parent: 18801be7f805b891876a6676ec7fac2e1acdec13
Author: Magnus Damm <damm@igel.co.jp>
AuthorDate: Thu Dec 25 18:17:18 2008 +0900
Committer: Paul Mundt <lethal@linux-sh.org>
CommitDate: Tue Jan 27 14:49:09 2009 +0900
sh: lockless gpio_get_value()
This patch separates the register read and write functions to
allow lockless gpio_get_value().
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
---
arch/sh/kernel/gpio.c | 126 ++++++++++++++++++++++++------------------------
1 files changed, 63 insertions(+), 63 deletions(-)
diff --git a/arch/sh/kernel/gpio.c b/arch/sh/kernel/gpio.c
index fe92ba1..f8397a0 100644
--- a/arch/sh/kernel/gpio.c
+++ b/arch/sh/kernel/gpio.c
@@ -46,9 +46,8 @@ static int enum_in_range(pinmux_enum_t enum_id, struct pinmux_range *r)
return 1;
}
-static int read_write_reg(unsigned long reg, unsigned long reg_width,
- unsigned long field_width, unsigned long in_pos,
- unsigned long value, int do_write)
+static int gpio_read_reg(unsigned long reg, unsigned long reg_width,
+ unsigned long field_width, unsigned long in_pos)
{
unsigned long data, mask, pos;
@@ -57,10 +56,9 @@ static int read_write_reg(unsigned long reg, unsigned long reg_width,
pos = reg_width - ((in_pos + 1) * field_width);
#ifdef DEBUG
- pr_info("%s, addr = %lx, value = %ld, pos = %ld, "
+ pr_info("read_reg: addr = %lx, pos = %ld, "
"r_width = %ld, f_width = %ld\n",
- do_write ? "write" : "read", reg, value, pos,
- reg_width, field_width);
+ reg, pos, reg_width, field_width);
#endif
switch (reg_width) {
@@ -75,24 +73,38 @@ static int read_write_reg(unsigned long reg, unsigned long reg_width,
break;
}
- if (!do_write)
- return (data >> pos) & mask;
+ return (data >> pos) & mask;
+}
+
+static void gpio_write_reg(unsigned long reg, unsigned long reg_width,
+ unsigned long field_width, unsigned long in_pos,
+ unsigned long value)
+{
+ unsigned long mask, pos;
+
+ mask = (1 << field_width) - 1;
+ pos = reg_width - ((in_pos + 1) * field_width);
- data &= ~(mask << pos);
- data |= value << pos;
+#ifdef DEBUG
+ pr_info("write_reg addr = %lx, value = %ld, pos = %ld, "
+ "r_width = %ld, f_width = %ld\n",
+ reg, value, pos, reg_width, field_width);
+#endif
+
+ mask = ~(mask << pos);
+ value = value << pos;
switch (reg_width) {
case 8:
- ctrl_outb(data, reg);
+ ctrl_outb((ctrl_inb(reg) & mask) | value, reg);
break;
case 16:
- ctrl_outw(data, reg);
+ ctrl_outw((ctrl_inw(reg) & mask) | value, reg);
break;
case 32:
- ctrl_outl(data, reg);
+ ctrl_outl((ctrl_inl(reg) & mask) | value, reg);
break;
}
- return 0;
}
static int setup_data_reg(struct pinmux_info *gpioc, unsigned gpio)
@@ -205,9 +217,9 @@ static int get_gpio_enum_id(struct pinmux_info *gpioc, unsigned gpio,
return -1;
}
-static int write_config_reg(struct pinmux_info *gpioc,
- struct pinmux_cfg_reg *crp,
- int index)
+static void write_config_reg(struct pinmux_info *gpioc,
+ struct pinmux_cfg_reg *crp,
+ int index)
{
unsigned long ncomb, pos, value;
@@ -215,8 +227,7 @@ static int write_config_reg(struct pinmux_info *gpioc,
pos = index / ncomb;
value = index % ncomb;
- return read_write_reg(crp->reg, crp->reg_width,
- crp->field_width, pos, value, 1);
+ gpio_write_reg(crp->reg, crp->reg_width, crp->field_width, pos, value);
}
static int check_config_reg(struct pinmux_info *gpioc,
@@ -229,8 +240,8 @@ static int check_config_reg(struct pinmux_info *gpioc,
pos = index / ncomb;
value = index % ncomb;
- if (read_write_reg(crp->reg, crp->reg_width,
- crp->field_width, pos, 0, 0) == value)
+ if (gpio_read_reg(crp->reg, crp->reg_width,
+ crp->field_width, pos) == value)
return 0;
return -1;
@@ -238,8 +249,8 @@ static int check_config_reg(struct pinmux_info *gpioc,
enum { GPIO_CFG_DRYRUN, GPIO_CFG_REQ, GPIO_CFG_FREE };
-int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,
- int pinmux_type, int cfg_mode)
+static int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,
+ int pinmux_type, int cfg_mode)
{
struct pinmux_cfg_reg *cr = NULL;
pinmux_enum_t enum_id;
@@ -305,8 +316,7 @@ int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,
break;
case GPIO_CFG_REQ:
- if (write_config_reg(gpioc, cr, index) != 0)
- goto out_err;
+ write_config_reg(gpioc, cr, index);
*cntp = *cntp + 1;
break;
@@ -393,9 +403,12 @@ EXPORT_SYMBOL(gpio_free);
static int pinmux_direction(struct pinmux_info *gpioc,
unsigned gpio, int new_pinmux_type)
{
- int ret, pinmux_type;
+ int pinmux_type;
+ int ret = -EINVAL;
+
+ if (!gpioc)
+ goto err_out;
- ret = -EINVAL;
pinmux_type = gpioc->gpios[gpio].flags & PINMUX_FLAG_TYPE;
switch (pinmux_type) {
@@ -433,68 +446,59 @@ int gpio_direction_input(unsigned gpio)
{
struct pinmux_info *gpioc = gpio_controller(gpio);
unsigned long flags;
- int ret = -EINVAL;
-
- if (!gpioc)
- goto err_out;
+ int ret;
spin_lock_irqsave(&gpio_lock, flags);
ret = pinmux_direction(gpioc, gpio, PINMUX_TYPE_INPUT);
spin_unlock_irqrestore(&gpio_lock, flags);
- err_out:
+
return ret;
}
EXPORT_SYMBOL(gpio_direction_input);
-static int __gpio_get_set_value(struct pinmux_info *gpioc,
- unsigned gpio, int value,
- int do_write)
+static void __gpio_set_value(struct pinmux_info *gpioc,
+ unsigned gpio, int value)
{
struct pinmux_data_reg *dr = NULL;
int bit = 0;
- if (get_data_reg(gpioc, gpio, &dr, &bit) != 0)
+ if (!gpioc || get_data_reg(gpioc, gpio, &dr, &bit) != 0)
BUG();
else
- value = read_write_reg(dr->reg, dr->reg_width,
- 1, bit, !!value, do_write);
-
- return value;
+ gpio_write_reg(dr->reg, dr->reg_width, 1, bit, !!value);
}
int gpio_direction_output(unsigned gpio, int value)
{
struct pinmux_info *gpioc = gpio_controller(gpio);
unsigned long flags;
- int ret = -EINVAL;
-
- if (!gpioc)
- goto err_out;
+ int ret;
spin_lock_irqsave(&gpio_lock, flags);
- __gpio_get_set_value(gpioc, gpio, value, 1);
+ __gpio_set_value(gpioc, gpio, value);
ret = pinmux_direction(gpioc, gpio, PINMUX_TYPE_OUTPUT);
spin_unlock_irqrestore(&gpio_lock, flags);
- err_out:
+
return ret;
}
EXPORT_SYMBOL(gpio_direction_output);
-int gpio_get_value(unsigned gpio)
+static int __gpio_get_value(struct pinmux_info *gpioc, unsigned gpio)
{
- struct pinmux_info *gpioc = gpio_controller(gpio);
- unsigned long flags;
- int value = 0;
+ struct pinmux_data_reg *dr = NULL;
+ int bit = 0;
- if (!gpioc)
+ if (!gpioc || get_data_reg(gpioc, gpio, &dr, &bit) != 0) {
BUG();
- else {
- spin_lock_irqsave(&gpio_lock, flags);
- value = __gpio_get_set_value(gpioc, gpio, 0, 0);
- spin_unlock_irqrestore(&gpio_lock, flags);
+ return 0;
}
- return value;
+ return gpio_read_reg(dr->reg, dr->reg_width, 1, bit);
+}
+
+int gpio_get_value(unsigned gpio)
+{
+ return __gpio_get_value(gpio_controller(gpio), gpio);
}
EXPORT_SYMBOL(gpio_get_value);
@@ -503,13 +507,9 @@ void gpio_set_value(unsigned gpio, int value)
struct pinmux_info *gpioc = gpio_controller(gpio);
unsigned long flags;
- if (!gpioc)
- BUG();
- else {
- spin_lock_irqsave(&gpio_lock, flags);
- __gpio_get_set_value(gpioc, gpio, value, 1);
- spin_unlock_irqrestore(&gpio_lock, flags);
- }
+ spin_lock_irqsave(&gpio_lock, flags);
+ __gpio_set_value(gpioc, gpio, value);
+ spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(gpio_set_value);
--
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