From: Magnus Damm Date: Thu, 25 Dec 2008 09:17:09 +0000 Subject: [PATCH 01/04] sh: make gpio_get/set_value() O(1) Message-Id: <20081225091709.7670.50390.sendpatchset@rx1.opensource.se> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org From: Magnus Damm This patch modifies the table based SuperH gpio implementation to make use of direct table lookups. With this change the functions gpio_get_value() and gpio_set_value() are O(1). Tested on Migo-R using bitbanging mmc. Performance is improved from 11 KBytes/s to 26 Kbytes/s. Signed-off-by: Magnus Damm --- arch/sh/include/asm/gpio.h | 7 +++++- arch/sh/kernel/gpio.c | 48 +++++++++++++++++++++++++++++++++----------- 2 files changed, 43 insertions(+), 12 deletions(-) --- 0001/arch/sh/include/asm/gpio.h +++ work/arch/sh/include/asm/gpio.h 2008-11-05 17:13:25.000000000 +0900 @@ -20,7 +20,7 @@ #endif typedef unsigned short pinmux_enum_t; -typedef unsigned char pinmux_flag_t; +typedef unsigned short pinmux_flag_t; #define PINMUX_TYPE_NONE 0 #define PINMUX_TYPE_FUNCTION 1 @@ -34,6 +34,11 @@ typedef unsigned char pinmux_flag_t; #define PINMUX_FLAG_WANT_PULLUP (1 << 3) #define PINMUX_FLAG_WANT_PULLDOWN (1 << 4) +#define PINMUX_FLAG_DBIT_SHIFT 5 +#define PINMUX_FLAG_DBIT (0x1f << PINMUX_FLAG_DBIT_SHIFT) +#define PINMUX_FLAG_DREG_SHIFT 10 +#define PINMUX_FLAG_DREG (0x3f << PINMUX_FLAG_DREG_SHIFT) + struct pinmux_gpio { pinmux_enum_t enum_id; pinmux_flag_t flags; --- 0001/arch/sh/kernel/gpio.c +++ work/arch/sh/kernel/gpio.c 2008-11-05 17:19:48.000000000 +0900 @@ -95,14 +95,13 @@ static int read_write_reg(unsigned long return 0; } -static int get_data_reg(struct pinmux_info *gpioc, unsigned gpio, - struct pinmux_data_reg **drp, int *bitp) +static int setup_data_reg(struct pinmux_info *gpioc, unsigned gpio) { - pinmux_enum_t enum_id = gpioc->gpios[gpio].enum_id; + struct pinmux_gpio *gpiop = &gpioc->gpios[gpio]; struct pinmux_data_reg *data_reg; int k, n; - if (!enum_in_range(enum_id, &gpioc->data)) + if (!enum_in_range(gpiop->enum_id, &gpioc->data)) return -1; k = 0; @@ -113,19 +112,38 @@ static int get_data_reg(struct pinmux_in break; for (n = 0; n < data_reg->reg_width; n++) { - if (data_reg->enum_ids[n] = enum_id) { - *drp = data_reg; - *bitp = n; + if (data_reg->enum_ids[n] = gpiop->enum_id) { + gpiop->flags &= ~PINMUX_FLAG_DREG; + gpiop->flags |= (k << PINMUX_FLAG_DREG_SHIFT); + gpiop->flags &= ~PINMUX_FLAG_DBIT; + gpiop->flags |= (n << PINMUX_FLAG_DBIT_SHIFT); return 0; - } } k++; } + BUG(); + return -1; } +static int get_data_reg(struct pinmux_info *gpioc, unsigned gpio, + struct pinmux_data_reg **drp, int *bitp) +{ + struct pinmux_gpio *gpiop = &gpioc->gpios[gpio]; + int k, n; + + if (!enum_in_range(gpiop->enum_id, &gpioc->data)) + return -1; + + k = (gpiop->flags & PINMUX_FLAG_DREG) >> PINMUX_FLAG_DREG_SHIFT; + n = (gpiop->flags & PINMUX_FLAG_DBIT) >> PINMUX_FLAG_DBIT_SHIFT; + *drp = gpioc->data_regs + k; + *bitp = n; + return 0; +} + static int get_config_reg(struct pinmux_info *gpioc, pinmux_enum_t enum_id, struct pinmux_cfg_reg **crp, int *indexp, unsigned long **cntp) @@ -341,7 +359,8 @@ int __gpio_request(unsigned gpio) BUG(); } - gpioc->gpios[gpio].flags = pinmux_type; + gpioc->gpios[gpio].flags &= ~PINMUX_FLAG_TYPE; + gpioc->gpios[gpio].flags |= pinmux_type; ret = 0; err_unlock: @@ -364,7 +383,8 @@ void gpio_free(unsigned gpio) pinmux_type = gpioc->gpios[gpio].flags & PINMUX_FLAG_TYPE; pinmux_config_gpio(gpioc, gpio, pinmux_type, GPIO_CFG_FREE); - gpioc->gpios[gpio].flags = PINMUX_TYPE_NONE; + gpioc->gpios[gpio].flags &= ~PINMUX_FLAG_TYPE; + gpioc->gpios[gpio].flags |= PINMUX_TYPE_NONE; spin_unlock_irqrestore(&gpio_lock, flags); } @@ -401,7 +421,8 @@ static int pinmux_direction(struct pinmu GPIO_CFG_REQ) != 0) BUG(); - gpioc->gpios[gpio].flags = new_pinmux_type; + gpioc->gpios[gpio].flags &= ~PINMUX_FLAG_TYPE; + gpioc->gpios[gpio].flags |= new_pinmux_type; ret = 0; err_out: @@ -494,9 +515,14 @@ EXPORT_SYMBOL(gpio_set_value); int register_pinmux(struct pinmux_info *pip) { + int k; + registered_gpio = pip; pr_info("pinmux: %s handling gpio %d -> %d\n", pip->name, pip->first_gpio, pip->last_gpio); + for (k = pip->first_gpio; k <= pip->last_gpio; k++) + setup_data_reg(pip, k); + return 0; }