diff options
Diffstat (limited to 'drivers/gpio/altera_pio.c')
| -rw-r--r-- | drivers/gpio/altera_pio.c | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/drivers/gpio/altera_pio.c b/drivers/gpio/altera_pio.c new file mode 100644 index 0000000..fb03760 --- /dev/null +++ b/drivers/gpio/altera_pio.c @@ -0,0 +1,299 @@ +/* + * Driver for Altera's PIO ip core + * + * Copyright (C) 2011 Missing Link Electronics + * Joachim Foerster <joachim@missinglinkelectronics.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * To use this driver, in your board's config. header: + * #define CONFIG_ALTERA_PIO + * #define CONFIG_SYS_ALTERA_PIO_NUM <number-of-pio-cores> + * #define CONFIG_SYS_ALTERA_PIO_GPIO_NUM <total-number-of-gpios> + * And in your board's early setup routine: + * altera_pio_init(<baseaddr>, <width>, 'i'|'o'|'t', + * <reset-value>, <neg-mask>, "label"); + * - 'i'|'o'|'t': PIO is input-only/output-only/tri-state + * - <reset-value>: for correct initial status display, output-only + * - <neg-mask> is meant to be used to in cases of active-low + * GPIOs, such as LEDs and buttons (on/pressed == 0). Each bit + * which is 1 in <neg-mask> inverts the corresponding GPIO's value + * before set/after get. So: gpio_set_value(gpio, 1) => LED on . + * + * Do NOT define CONFIG_SYS_GPIO_BASE ! + * + * Optionally, in your board's config. header: + * - To force a GPIO numbering scheme like in Linux ... + * #define CONFIG_GPIO_DOWNTO_NUMBERING + * ... starting with 255 (default) + * #define CONFIG_GPIO_DOWNTO_MAX 255 + */ +#include <common.h> +#include <asm/io.h> +#include <asm/gpio.h> + +#ifdef CONFIG_GPIO_DOWNTO_NUMBERING +#ifndef CONFIG_GPIO_DOWNTO_MAX +#define CONFIG_GPIO_DOWNTO_MAX 255 +#endif +#endif + +#define ALTERA_PIO_DATA 0x0 +#define ALTERA_PIO_DIR 0x4 + +#define GPIO_LABEL_SIZE 9 + + +static struct altera_pio { + u32 base; + u8 width; + char iot; + u32 negmask; + u32 sh_data; + u32 sh_dir; + int gidx; + char label[GPIO_LABEL_SIZE]; +} pios[CONFIG_SYS_ALTERA_PIO_NUM]; + +static int pio_num; + +static struct altera_pio_gpio { + unsigned num; + struct altera_pio *pio; + char reqlabel[GPIO_LABEL_SIZE]; +} gpios[CONFIG_SYS_ALTERA_PIO_GPIO_NUM]; + +static int pio_gpio_num; + + +static int altera_pio_gidx(unsigned gpio) +{ + int i; + + for (i = 0; i < pio_gpio_num; ++i) { + if (gpio == gpios[i].num) + break; + } + if (i >= pio_gpio_num) + return -1; + return i; +} + +static struct altera_pio *altera_pio_get_and_mask(unsigned gpio, u32 *mask) +{ + int gidx = altera_pio_gidx(gpio); + if (gidx < 0) + return NULL; + if (mask) + *mask = 1 << (gidx - gpios[gidx].pio->gidx); + return gpios[gidx].pio; +} + +#define altera_pio_use_gidx(_gidx, _reqlabel) \ + { strncpy(gpios[_gidx].reqlabel, _reqlabel, GPIO_LABEL_SIZE); } +#define altera_pio_unuse_gidx(_gidx) { gpios[_gidx].reqlabel[0] = '\0'; } +#define altera_pio_is_gidx_used(_gidx) (gpios[_gidx].reqlabel[0] != '\0') + +static int altera_pio_gpio_init(struct altera_pio *pio, u8 width) +{ + u8 gidx = pio_gpio_num; + int i; + + if (!width) + return -1; + if ((pio_gpio_num + width) > CONFIG_SYS_ALTERA_PIO_GPIO_NUM) + return -1; + + for (i = 0; i < width; ++i) { +#ifdef CONFIG_GPIO_DOWNTO_NUMBERING + gpios[pio_gpio_num + i].num = \ + CONFIG_GPIO_DOWNTO_MAX + 1 - gidx - width + i; +#else + gpios[pio_gpio_num + i].num = pio_gpio_num + i; +#endif + gpios[pio_gpio_num + i].pio = pio; + altera_pio_unuse_gidx(pio_gpio_num + i); + } + pio_gpio_num += width; + return gidx; +} + +int altera_pio_init(u32 base, u8 width, char iot, u32 rstval, u32 negmask, + const char *label) +{ + if (pio_num >= CONFIG_SYS_ALTERA_PIO_NUM) + return -1; + + pios[pio_num].base = base; + pios[pio_num].width = width; + pios[pio_num].iot = iot; + switch (iot) { + case 'i': + /* input only */ + pios[pio_num].sh_dir = 0; + pios[pio_num].sh_data = readl(base + ALTERA_PIO_DATA); + break; + case 'o': + /* output only */ + pios[pio_num].sh_dir = 0xffffffff & ((1 << width) - 1); + pios[pio_num].sh_data = rstval; + break; + case 't': + /* bidir, tri-state */ + pios[pio_num].sh_dir = readl(base + ALTERA_PIO_DIR); + pios[pio_num].sh_data = readl(base + ALTERA_PIO_DATA); + break; + default: + return -1; + } + pios[pio_num].negmask = negmask & ((1 << width) - 1); + pios[pio_num].gidx = altera_pio_gpio_init(&pios[pio_num], width); + if (pios[pio_num].gidx < 0) + return -1; + strncpy(pios[pio_num].label, label, GPIO_LABEL_SIZE); + return pio_num++; +} + +void altera_pio_info(void) +{ + int i; + int j; + int gidx; + u32 mask; + + for (i = 0; i < pio_num; ++i) { + printf("Altera PIO % 2d, @0x%08x, " + "width: %u, label: %s\n", + i, pios[i].base, pios[i].width, pios[i].label); + gidx = pios[i].gidx; + for (j = gidx; j < (gidx + pios[i].width); ++j) { + mask = 1 << (j - gidx); + printf("\tGPIO % 4d: %s %s [%c] %s\n", + gpios[j].num, + gpios[j].pio->sh_dir & mask ? "out" : " in", + gpio_get_value(gpios[j].num) ? "set" : "clr", + altera_pio_is_gidx_used(j) ? 'x' : ' ', + gpios[j].reqlabel); + } + } +} + + +int gpio_request(unsigned gpio, const char *label) +{ + int gidx = altera_pio_gidx(gpio); + if (gidx < 0) + return gidx; + if (altera_pio_is_gidx_used(gidx)) + return -1; + + altera_pio_use_gidx(gidx, label); + return 0; +} + +int gpio_free(unsigned gpio) +{ + int gidx = altera_pio_gidx(gpio); + if (gidx < 0) + return gidx; + if (!altera_pio_is_gidx_used(gidx)) + return -1; + + altera_pio_unuse_gidx(gidx); + return 0; +} + +int gpio_direction_input(unsigned gpio) +{ + u32 mask; + struct altera_pio *pio; + + pio = altera_pio_get_and_mask(gpio, &mask); + if (!pio) + return -1; + if (pio->iot == 'o') + return -1; + + writel(pio->sh_dir &= ~mask, pio->base + ALTERA_PIO_DIR); + return 0; +} + +int gpio_direction_output(unsigned gpio, int value) +{ + u32 mask; + struct altera_pio *pio; + + pio = altera_pio_get_and_mask(gpio, &mask); + if (!pio) + return -1; + if (pio->iot == 'i') + return -1; + + value = (pio->negmask & mask) ? !value : value; + if (value) + pio->sh_data |= mask; + else + pio->sh_data &= ~mask; + writel(pio->sh_data, pio->base + ALTERA_PIO_DATA); + writel(pio->sh_dir |= mask, pio->base + ALTERA_PIO_DIR); + return 0; +} + +int gpio_get_value(unsigned gpio) +{ + u32 mask; + struct altera_pio *pio; + u32 val; + + pio = altera_pio_get_and_mask(gpio, &mask); + if (!pio) + return -1; + + if ((pio->sh_dir & mask) || (pio->iot == 'o')) + val = pio->sh_data & mask; + else + val = readl(pio->base + ALTERA_PIO_DATA) & mask; + return (pio->negmask & mask) ? !val : val; +} + +void gpio_set_value(unsigned gpio, int value) +{ + u32 mask; + struct altera_pio *pio; + + pio = altera_pio_get_and_mask(gpio, &mask); + if (!pio) + return; + if (pio->iot == 'i') + return; + + value = (pio->negmask & mask) ? !value : value; + if (value) + pio->sh_data |= mask; + else + pio->sh_data &= ~mask; + writel(pio->sh_data, pio->base + ALTERA_PIO_DATA); + return; +} + +int gpio_is_valid(int number) +{ + int gidx = altera_pio_gidx(number); + + if (gidx < 0) + return 1; + return 0; +} |