mirror of
https://github.com/AsahiLinux/u-boot
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118 lines
2.4 KiB
C
118 lines
2.4 KiB
C
/*
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* Copyright (C) 2012 Boundary Devices Inc.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <malloc.h>
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#include <asm/arch/clock.h>
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#include <asm/arch/imx-regs.h>
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#include <asm/errno.h>
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#include <asm/gpio.h>
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#include <asm/imx-common/mxc_i2c.h>
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#include <watchdog.h>
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int force_idle_bus(void *priv)
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{
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int i;
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int sda, scl;
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ulong elapsed, start_time;
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struct i2c_pads_info *p = (struct i2c_pads_info *)priv;
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int ret = 0;
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gpio_direction_input(p->sda.gp);
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gpio_direction_input(p->scl.gp);
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imx_iomux_v3_setup_pad(p->sda.gpio_mode);
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imx_iomux_v3_setup_pad(p->scl.gpio_mode);
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sda = gpio_get_value(p->sda.gp);
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scl = gpio_get_value(p->scl.gp);
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if ((sda & scl) == 1)
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goto exit; /* Bus is idle already */
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printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__,
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sda, scl, p->sda.gp, p->scl.gp);
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/* Send high and low on the SCL line */
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for (i = 0; i < 9; i++) {
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gpio_direction_output(p->scl.gp, 0);
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udelay(50);
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gpio_direction_input(p->scl.gp);
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udelay(50);
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}
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start_time = get_timer(0);
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for (;;) {
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sda = gpio_get_value(p->sda.gp);
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scl = gpio_get_value(p->scl.gp);
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if ((sda & scl) == 1)
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break;
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WATCHDOG_RESET();
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elapsed = get_timer(start_time);
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if (elapsed > (CONFIG_SYS_HZ / 5)) { /* .2 seconds */
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ret = -EBUSY;
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printf("%s: failed to clear bus, sda=%d scl=%d\n",
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__func__, sda, scl);
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break;
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}
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}
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exit:
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imx_iomux_v3_setup_pad(p->sda.i2c_mode);
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imx_iomux_v3_setup_pad(p->scl.i2c_mode);
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return ret;
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}
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static void * const i2c_bases[] = {
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(void *)I2C1_BASE_ADDR,
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(void *)I2C2_BASE_ADDR,
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#ifdef I2C3_BASE_ADDR
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(void *)I2C3_BASE_ADDR,
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#endif
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#ifdef I2C4_BASE_ADDR
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(void *)I2C4_BASE_ADDR,
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#endif
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};
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/* i2c_index can be from 0 - 3 */
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int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
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struct i2c_pads_info *p)
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{
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char name[9];
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int ret;
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if (i2c_index >= ARRAY_SIZE(i2c_bases))
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return -EINVAL;
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snprintf(name, sizeof(name), "i2c_sda%01d", i2c_index);
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ret = gpio_request(p->sda.gp, name);
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if (ret)
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return ret;
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snprintf(name, sizeof(name), "i2c_scl%01d", i2c_index);
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ret = gpio_request(p->scl.gp, name);
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if (ret)
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goto err_req;
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/* Enable i2c clock */
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ret = enable_i2c_clk(1, i2c_index);
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if (ret)
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goto err_clk;
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/* Make sure bus is idle */
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ret = force_idle_bus(p);
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if (ret)
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goto err_idle;
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#ifndef CONFIG_DM_I2C
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bus_i2c_init(i2c_index, speed, slave_addr, force_idle_bus, p);
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#endif
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return 0;
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err_idle:
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err_clk:
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gpio_free(p->scl.gp);
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err_req:
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gpio_free(p->sda.gp);
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return ret;
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}
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