diff options
Diffstat (limited to 'drivers/gpio/db8500_gpio.c')
| -rw-r--r-- | drivers/gpio/db8500_gpio.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/drivers/gpio/db8500_gpio.c b/drivers/gpio/db8500_gpio.c new file mode 100644 index 0000000000..d5cb383e85 --- /dev/null +++ b/drivers/gpio/db8500_gpio.c @@ -0,0 +1,221 @@ +/* + * Code ported from Nomadik GPIO driver in ST-Ericsson Linux kernel code. + * The purpose is that GPIO config found in kernel should work by simply + * copy-paste it to U-boot. + * + * Original Linux authors: + * Copyright (C) 2008,2009 STMicroelectronics + * Copyright (C) 2009 Alessandro Rubini <rubini@unipv.it> + * Rewritten based on work by Prafulla WADASKAR <prafulla.wadaskar@st.com> + * + * Ported to U-boot by: + * Copyright (C) 2010 Joakim Axelsson <joakim.axelsson AT stericsson.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <common.h> +#include <asm/io.h> + +#include <asm/arch/db8500_gpio.h> +#include <asm/arch/db8500_pincfg.h> +#include <linux/compiler.h> + +#define IO_ADDR(x) (void *) (x) + +/* + * The GPIO module in the db8500 Systems-on-Chip is an + * AMBA device, managing 32 pins and alternate functions. The logic block + * is currently only used in the db8500. + */ + +#define GPIO_TOTAL_PINS 268 +#define GPIO_PINS_PER_BLOCK 32 +#define GPIO_BLOCKS_COUNT (GPIO_TOTAL_PINS/GPIO_PINS_PER_BLOCK + 1) +#define GPIO_BLOCK(pin) (((pin + GPIO_PINS_PER_BLOCK) >> 5) - 1) +#define GPIO_PIN_WITHIN_BLOCK(pin) ((pin)%(GPIO_PINS_PER_BLOCK)) + +/* Register in the logic block */ +#define DB8500_GPIO_DAT 0x00 +#define DB8500_GPIO_DATS 0x04 +#define DB8500_GPIO_DATC 0x08 +#define DB8500_GPIO_PDIS 0x0c +#define DB8500_GPIO_DIR 0x10 +#define DB8500_GPIO_DIRS 0x14 +#define DB8500_GPIO_DIRC 0x18 +#define DB8500_GPIO_SLPC 0x1c +#define DB8500_GPIO_AFSLA 0x20 +#define DB8500_GPIO_AFSLB 0x24 + +#define DB8500_GPIO_RIMSC 0x40 +#define DB8500_GPIO_FIMSC 0x44 +#define DB8500_GPIO_IS 0x48 +#define DB8500_GPIO_IC 0x4c +#define DB8500_GPIO_RWIMSC 0x50 +#define DB8500_GPIO_FWIMSC 0x54 +#define DB8500_GPIO_WKS 0x58 + +static void __iomem *get_gpio_addr(unsigned gpio) +{ + /* Our list of GPIO chips */ + static void __iomem *gpio_addrs[GPIO_BLOCKS_COUNT] = { + IO_ADDR(CFG_GPIO_0_BASE), + IO_ADDR(CFG_GPIO_1_BASE), + IO_ADDR(CFG_GPIO_2_BASE), + IO_ADDR(CFG_GPIO_3_BASE), + IO_ADDR(CFG_GPIO_4_BASE), + IO_ADDR(CFG_GPIO_5_BASE), + IO_ADDR(CFG_GPIO_6_BASE), + IO_ADDR(CFG_GPIO_7_BASE), + IO_ADDR(CFG_GPIO_8_BASE) + }; + + return gpio_addrs[GPIO_BLOCK(gpio)]; +} + +static unsigned get_gpio_offset(unsigned gpio) +{ + return GPIO_PIN_WITHIN_BLOCK(gpio); +} + +/* Can only be called from config_pin. Don't configure alt-mode directly */ +static void gpio_set_mode(unsigned gpio, enum db8500_gpio_alt mode) +{ + void __iomem *addr = get_gpio_addr(gpio); + unsigned offset = get_gpio_offset(gpio); + u32 bit = 1 << offset; + u32 afunc, bfunc; + + afunc = readl(addr + DB8500_GPIO_AFSLA) & ~bit; + bfunc = readl(addr + DB8500_GPIO_AFSLB) & ~bit; + if (mode & DB8500_GPIO_ALT_A) + afunc |= bit; + if (mode & DB8500_GPIO_ALT_B) + bfunc |= bit; + writel(afunc, addr + DB8500_GPIO_AFSLA); + writel(bfunc, addr + DB8500_GPIO_AFSLB); +} + +/** + * db8500_gpio_set_pull() - enable/disable pull up/down on a gpio + * @gpio: pin number + * @pull: one of DB8500_GPIO_PULL_DOWN, DB8500_GPIO_PULL_UP, + * and DB8500_GPIO_PULL_NONE + * + * Enables/disables pull up/down on a specified pin. This only takes effect if + * the pin is configured as an input (either explicitly or by the alternate + * function). + * + * NOTE: If enabling the pull up/down, the caller must ensure that the GPIO is + * configured as an input. Otherwise, due to the way the controller registers + * work, this function will change the value output on the pin. + */ +void db8500_gpio_set_pull(unsigned gpio, enum db8500_gpio_pull pull) +{ + void __iomem *addr = get_gpio_addr(gpio); + unsigned offset = get_gpio_offset(gpio); + u32 bit = 1 << offset; + u32 pdis; + + pdis = readl(addr + DB8500_GPIO_PDIS); + if (pull == DB8500_GPIO_PULL_NONE) + pdis |= bit; + else + pdis &= ~bit; + writel(pdis, addr + DB8500_GPIO_PDIS); + + if (pull == DB8500_GPIO_PULL_UP) + writel(bit, addr + DB8500_GPIO_DATS); + else if (pull == DB8500_GPIO_PULL_DOWN) + writel(bit, addr + DB8500_GPIO_DATC); +} + +void db8500_gpio_make_input(unsigned gpio) +{ + void __iomem *addr = get_gpio_addr(gpio); + unsigned offset = get_gpio_offset(gpio); + + writel(1 << offset, addr + DB8500_GPIO_DIRC); +} + +int db8500_gpio_get_input(unsigned gpio) +{ + void __iomem *addr = get_gpio_addr(gpio); + unsigned offset = get_gpio_offset(gpio); + u32 bit = 1 << offset; + + printf("db8500_gpio_get_input gpio=%u addr=%p offset=%u bit=%#x\n", + gpio, addr, offset, bit); + + return (readl(addr + DB8500_GPIO_DAT) & bit) != 0; +} + +void db8500_gpio_make_output(unsigned gpio, int val) +{ + void __iomem *addr = get_gpio_addr(gpio); + unsigned offset = get_gpio_offset(gpio); + + writel(1 << offset, addr + DB8500_GPIO_DIRS); + db8500_gpio_set_output(gpio, val); +} + +void db8500_gpio_set_output(unsigned gpio, int val) +{ + void __iomem *addr = get_gpio_addr(gpio); + unsigned offset = get_gpio_offset(gpio); + + if (val) + writel(1 << offset, addr + DB8500_GPIO_DATS); + else + writel(1 << offset, addr + DB8500_GPIO_DATC); +} + +/** + * config_pin - configure a pin's mux attributes + * @cfg: pin confguration + * + * Configures a pin's mode (alternate function or GPIO), its pull up status, + * and its sleep mode based on the specified configuration. The @cfg is + * usually one of the SoC specific macros defined in mach/<soc>-pins.h. These + * are constructed using, and can be further enhanced with, the macros in + * plat/pincfg.h. + * + * If a pin's mode is set to GPIO, it is configured as an input to avoid + * side-effects. The gpio can be manipulated later using standard GPIO API + * calls. + */ +static void config_pin(unsigned long cfg) +{ + int pin = PIN_NUM(cfg); + int pull = PIN_PULL(cfg); + int af = PIN_ALT(cfg); + int output = PIN_DIR(cfg); + int val = PIN_VAL(cfg); + + if (output) + db8500_gpio_make_output(pin, val); + else { + db8500_gpio_make_input(pin); + db8500_gpio_set_pull(pin, pull); + } + + gpio_set_mode(pin, af); +} + +/** + * db8500_config_pins - configure several pins at once + * @cfgs: array of pin configurations + * @num: number of elments in the array + * + * Configures several pins using config_pin(). Refer to that function for + * further information. + */ +void db8500_gpio_config_pins(unsigned long *cfgs, size_t num) +{ + size_t i; + + for (i = 0; i < num; i++) + config_pin(cfgs[i]); +} |