From: Magnus Damm Date: Thu, 25 Dec 2008 09:17:18 +0000 (+0900) Subject: sh: lockless gpio_get_value() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0fc64cc0a27288e77ee8e12648d59632649371fc;p=linux-beck.git 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 Signed-off-by: Paul Mundt --- diff --git a/arch/sh/kernel/gpio.c b/arch/sh/kernel/gpio.c index fe92ba151b89..f8397a09491c 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);