diff options
Diffstat (limited to 'arch/arm/cpu/armv7/imx-common')
| -rw-r--r-- | arch/arm/cpu/armv7/imx-common/Makefile | 4 | ||||
| -rw-r--r-- | arch/arm/cpu/armv7/imx-common/i2c.c | 99 |
2 files changed, 102 insertions, 1 deletions
diff --git a/arch/arm/cpu/armv7/imx-common/Makefile b/arch/arm/cpu/armv7/imx-common/Makefile index 53296fa..bf36be5 100644 --- a/arch/arm/cpu/armv7/imx-common/Makefile +++ b/arch/arm/cpu/armv7/imx-common/Makefile @@ -27,7 +27,9 @@ include $(TOPDIR)/config.mk LIB = $(obj)libimx-common.o -COBJS = iomux-v3.o timer.o cpu.o speed.o +COBJS-y = iomux-v3.o timer.o cpu.o speed.o +COBJS-$(CONFIG_I2C_MXC) += i2c.o +COBJS := $(sort $(COBJS-y)) SRCS := $(SOBJS:.o=.S) $(COBJS:.o=.c) OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS)) diff --git a/arch/arm/cpu/armv7/imx-common/i2c.c b/arch/arm/cpu/armv7/imx-common/i2c.c new file mode 100644 index 0000000..da2b26f --- /dev/null +++ b/arch/arm/cpu/armv7/imx-common/i2c.c @@ -0,0 +1,99 @@ +/* + * Copyright (C) 2012 Boundary Devices Inc. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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 + */ +#include <common.h> +#include <asm/arch/clock.h> +#include <asm/arch/imx-regs.h> +#include <asm/errno.h> +#include <asm/gpio.h> +#include <asm/imx-common/mxc_i2c.h> +#include <watchdog.h> + +static int force_idle_bus(void *priv) +{ + int i; + int sda, scl; + ulong elapsed, start_time; + struct i2c_pads_info *p = (struct i2c_pads_info *)priv; + int ret = 0; + + gpio_direction_input(p->sda.gp); + gpio_direction_input(p->scl.gp); + + imx_iomux_v3_setup_pad(p->sda.gpio_mode); + imx_iomux_v3_setup_pad(p->scl.gpio_mode); + + sda = gpio_get_value(p->sda.gp); + scl = gpio_get_value(p->scl.gp); + if ((sda & scl) == 1) + goto exit; /* Bus is idle already */ + + printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__, + sda, scl, p->sda.gp, p->scl.gp); + /* Send high and low on the SCL line */ + for (i = 0; i < 9; i++) { + gpio_direction_output(p->scl.gp, 0); + udelay(50); + gpio_direction_input(p->scl.gp); + udelay(50); + } + start_time = get_timer(0); + for (;;) { + sda = gpio_get_value(p->sda.gp); + scl = gpio_get_value(p->scl.gp); + if ((sda & scl) == 1) + break; + WATCHDOG_RESET(); + elapsed = get_timer(start_time); + if (elapsed > (CONFIG_SYS_HZ / 5)) { /* .2 seconds */ + ret = -EBUSY; + printf("%s: failed to clear bus, sda=%d scl=%d\n", + __func__, sda, scl); + break; + } + } +exit: + imx_iomux_v3_setup_pad(p->sda.i2c_mode); + imx_iomux_v3_setup_pad(p->scl.i2c_mode); + return ret; +} + +static void * const i2c_bases[] = { + (void *)I2C1_BASE_ADDR, + (void *)I2C2_BASE_ADDR, +#ifdef I2C3_BASE_ADDR + (void *)I2C3_BASE_ADDR, +#endif +}; + +/* i2c_index can be from 0 - 2 */ +void setup_i2c(unsigned i2c_index, int speed, int slave_addr, + struct i2c_pads_info *p) +{ + if (i2c_index >= ARRAY_SIZE(i2c_bases)) + return; + /* Enable i2c clock */ + enable_i2c_clk(1, i2c_index); + /* Make sure bus is idle */ + force_idle_bus(p); + bus_i2c_init(i2c_bases[i2c_index], speed, slave_addr, + force_idle_bus, p); +} |