--- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -505,6 +505,8 @@ config PCI_HOST_VIA82C505 depends on PCI && ARCH_SHARK default y +source "drivers/gpio/Kconfig" + source "drivers/pci/Kconfig" source "drivers/pcmcia/Kconfig" --- a/drivers/Makefile +++ b/drivers/Makefile @@ -81,3 +81,4 @@ obj-$(CONFIG_GENERIC_TIME) += clocksourc obj-$(CONFIG_DMA_ENGINE) += dma/ obj-$(CONFIG_HID) += hid/ obj-$(CONFIG_PPC_PS3) += ps3/ +obj-$(CONFIG_PROC_GPIO) += gpio/ --- /dev/null +++ b/drivers/gpio/Kconfig @@ -0,0 +1,13 @@ +config PROC_GPIO + tristate "GPIO /proc interface" + depends on PXA25x || PXA27x + help + This enables an interface under /proc/gpio which allows reading or setting + of any GPIO, and also changing the GPIO alt function mode of any line. + +config PROC_GPIO_DEBUG + boolean "Enable /proc/gpio debug logging" + depends on PROC_GPIO + help + This enables printk logging of activity done through /proc/gpio + --- /dev/null +++ b/drivers/gpio/Makefile @@ -0,0 +1,2 @@ +# Expose GPIOs under /proc +obj-$(CONFIG_PROC_GPIO) += proc_gpio.o --- /dev/null +++ b/drivers/gpio/proc_gpio.c @@ -0,0 +1,276 @@ +/* + * + * PXA25x GPIOs exposed under /proc for reading and writing + * They will show up under /proc/gpio/NN + * + * Based on patch 1773/1 in the arm kernel patch repository at arm.linux.co.uk + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/proc_fs.h> +#include <linux/string.h> +#include <linux/ctype.h> + +#include <asm/hardware.h> +#include <asm/arch/pxa-regs.h> +#include <asm/uaccess.h> + +static struct proc_dir_entry *proc_gpio_parent; +static struct proc_dir_entry *proc_gpios[PXA_LAST_GPIO + 1]; + +typedef struct +{ + int gpio; + char name[32]; +} gpio_summary_type; + +static gpio_summary_type gpio_summaries[PXA_LAST_GPIO + 1]; + +static int proc_gpio_write(struct file *file, const char __user *buf, + unsigned long count, void *data) +{ + char *cur, lbuf[count + 1]; + gpio_summary_type *summary = data; + u32 altfn, direction, setclear, gafr; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + memset(lbuf, 0, count + 1); + + if (copy_from_user(lbuf, buf, count)) + return -EFAULT; + + cur = lbuf; + + // Initialize to current state + altfn = ((GAFR(summary->gpio) >> ((summary->gpio & 0x0f) << 0x01)) & 0x03); + direction = GPDR(summary->gpio) & GPIO_bit(summary->gpio); + setclear = GPLR(summary->gpio) & GPIO_bit(summary->gpio); + while(1) + { + // We accept options: {GPIO|AF1|AF2|AF3}, {set|clear}, {in|out} + // Anything else is an error + while(cur[0] && (isspace(cur[0]) || ispunct(cur[0]))) cur = &(cur[1]); + + if('\0' == cur[0]) break; + + // Ok, so now we're pointing at the start of something + switch(cur[0]) + { + case 'G': + // Check that next is "PIO" -- '\0' will cause safe short-circuit if end of buf + if(!(cur[1] == 'P' && cur[2] == 'I' && cur[3] == 'O')) goto parse_error; + // Ok, so set this GPIO to GPIO (non-ALT) function + altfn = 0; + cur = &(cur[4]); + break; + case 'A': + if(!(cur[1] == 'F' && cur[2] >= '1' && cur[2] <= '3')) goto parse_error; + altfn = cur[2] - '0'; + cur = &(cur[3]); + break; + case 's': + if(!(cur[1] == 'e' && cur[2] == 't')) goto parse_error; + setclear = 1; + cur = &(cur[3]); + break; + case 'c': + if(!(cur[1] == 'l' && cur[2] == 'e' && cur[3] == 'a' && cur[4] == 'r')) goto parse_error; + setclear = 0; + cur = &(cur[5]); + break; + case 'i': + if(!(cur[1] == 'n')) goto parse_error; + direction = 0; + cur = &(cur[2]); + break; + case 'o': + if(!(cur[1] == 'u' && cur[2] == 't')) goto parse_error; + direction = 1; + cur = &(cur[3]); + break; + default: goto parse_error; + } + } + // Ok, now set gpio mode and value + if(direction) + GPDR(summary->gpio) |= GPIO_bit(summary->gpio); + else + GPDR(summary->gpio) &= ~GPIO_bit(summary->gpio); + + gafr = GAFR(summary->gpio) & ~(0x3 << (((summary->gpio) & 0xf)*2)); + GAFR(summary->gpio) = gafr | (altfn << (((summary->gpio) & 0xf)*2)); + + if(direction && !altfn) + { + if(setclear) GPSR(summary->gpio) = GPIO_bit(summary->gpio); + else GPCR(summary->gpio) = GPIO_bit(summary->gpio); + } + +#ifdef CONFIG_PROC_GPIO_DEBUG + printk(KERN_INFO "Set (%s,%s,%s) via /proc/gpio/%s\n",altfn ? (altfn == 1 ? "AF1" : (altfn == 2 ? "AF2" : "AF3")) : "GPIO", + direction ? "out" : "in", + setclear ? "set" : "clear", + summary->name); +#endif + + return count; + +parse_error: + printk(KERN_CRIT "Parse error: Expect \"[GPIO|AF1|AF2|AF3]|[set|clear]|[in|out] ...\"\n"); + return -EINVAL; +} + +static int proc_gpio_read(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + char *p = page; + gpio_summary_type *summary = data; + int len, i, af; + i = summary->gpio; + + p += sprintf(p, "%d\t%s\t%s\t%s\n", i, + (af = ((GAFR(i) >> ((i & 0x0f) << 0x01)) & 0x03)) ? (af == 1 ? "AF1" : (af == 2 ? "AF2" : "AF3")) : "GPIO", + (GPDR(i) & GPIO_bit(i)) ? "out" : "in", + (GPLR(i) & GPIO_bit(i)) ? "set" : "clear"); + + len = (p - page) - off; + + if(len < 0) + { + len = 0; + } + + *eof = (len <= count) ? 1 : 0; + *start = page + off; + + return len; +} + + +#ifdef CONFIG_PXA25x +static const char const *GAFR_DESC[] = { "GAFR0_L", "GAFR0_U", "GAFR1_L", "GAFR1_U", "GAFR2_L", "GAFR2_U" }; +#elif defined(CONFIG_PXA27x) +static const char const *GAFR_DESC[] = { "GAFR0_L", "GAFR0_U", "GAFR1_L", "GAFR1_U", "GAFR2_L", "GAFR2_U", "GAFR3_L", "GAFR3_U" }; +#endif + +static int proc_gafr_read(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + char *p = page; + int i, len; + + for(i=0; i<ARRAY_SIZE(GAFR_DESC); i++) + { + p += sprintf(p, "%s: %08x\n", GAFR_DESC[i], GAFR(i*16)); + } + + len = (p - page) - off; + + if(len < 0) + { + len = 0; + } + + *eof = (len <= count) ? 1 : 0; + *start = page + off; + + return len; +} + +static int proc_gpdr_read(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + char *p = page; + int i, len; + + for(i=0; i<=2; i++) + { + p += sprintf(p, "GPDR%d: %08x\n", i, GPDR(i * 32)); + } + + len = (p - page) - off; + + if(len < 0) + { + len = 0; + } + + *eof = (len <= count) ? 1 : 0; + *start = page + off; + + return len; +} + +static int proc_gplr_read(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + char *p = page; + int i, len; + + for(i=0; i<=2; i++) + { + p += sprintf(p, "GPLR%d: %08x\n", i, GPLR(i * 32)); + } + + len = (p - page) - off; + + if(len < 0) + { + len = 0; + } + + *eof = (len <= count) ? 1 : 0; + *start = page + off; + + return len; +} + +static int __init gpio_init(void) +{ + int i; + + proc_gpio_parent = create_proc_entry("gpio", S_IFDIR | S_IRUGO | S_IXUGO, NULL); + if(!proc_gpio_parent) return 0; + + for(i=0; i < (PXA_LAST_GPIO+1); i++) + { + gpio_summaries[i].gpio = i; + sprintf(gpio_summaries[i].name, "GPIO%d", i); + proc_gpios[i] = create_proc_entry(gpio_summaries[i].name, 0644, proc_gpio_parent); + if(proc_gpios[i]) + { + proc_gpios[i]->data = &gpio_summaries[i]; + proc_gpios[i]->read_proc = proc_gpio_read; + proc_gpios[i]->write_proc = proc_gpio_write; + } + } + + create_proc_read_entry("GAFR", 0444, proc_gpio_parent, proc_gafr_read, NULL); + create_proc_read_entry("GPDR", 0444, proc_gpio_parent, proc_gpdr_read, NULL); + create_proc_read_entry("GPLR", 0444, proc_gpio_parent, proc_gplr_read, NULL); + + return 0; +} + +static void gpio_exit(void) +{ + int i; + + remove_proc_entry("GAFR", proc_gpio_parent); + remove_proc_entry("GPDR", proc_gpio_parent); + remove_proc_entry("GPLR", proc_gpio_parent); + + for(i=0; i < (PXA_LAST_GPIO+1); i++) + { + if(proc_gpios[i]) remove_proc_entry(gpio_summaries[i].name, proc_gpio_parent); + } + if(proc_gpio_parent) remove_proc_entry("gpio", NULL); +} + +module_init(gpio_init); +module_exit(gpio_exit); +MODULE_LICENSE("GPL");