u-boot/arch/arm/imx-common/i2c-mxv7.c

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/*
* Copyright (C) 2012 Boundary Devices Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <malloc.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>
i2c: mxc: refactor i2c driver and support dm 1. Introduce a new structure `struct mxc_i2c_bus`, this structure will used for non-DM and DM. 2. Remove `struct mxc_i2c_regs` structure, but use register offset to access registers based on `base` entry of `struct mxc_i2c_bus`. 3. Remove most `#ifdef I2C_QUIRK_REG`. Using driver_data to contain platform flags. A new flag is introduced, I2C_QUIRK_FLAG. 4. Most functions use `struct mxc_i2c_bus` as one of the parameters. Make most functions common to DM and non-DM, try to avoid duplicated code. 5. Support DM, but pinctrl is not included. Pinmux setting is still set by setup_i2c, but we do not need bus_i2c_init for DM. 6. struct i2c_parms and struct sram_data are removed. 7. Remove bus_i2c_read bus_i2c_write prototype in header file. The frist paramter of bus_i2c_init is modified to i2c index. Add new prototype i2c_idle_bus and force_bus_idle. Since bus_i2c_init is not good for DM I2C and pinctrl is missed, we use a weak function for i2c_idle_bus. Board file take the responsibility to implement this function, like this: " int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus) { if (i2c_bus->index == 0) force_bus_idle(i2c_pads_info0); else if (i2c_bus->index == 1) force_bus_idle(i2c_pads_info1); else xxxxxx } " 8. Introduce a weak function, enable_i2c_clk 9. Tested on an i.MX7 platform. Log info: => dm tree Class Probed Name ---------------------------------------- root [ + ] root_driver simple_bus [ ] |-- soc simple_bus [ ] | |-- aips-bus@30000000 simple_bus [ ] | | |-- anatop@30360000 simple_bus [ ] | | `-- snvs@30370000 simple_bus [ ] | |-- aips-bus@30400000 simple_bus [ ] | `-- aips-bus@30800000 i2c [ ] | |-- i2c@30a20000 i2c [ ] | `-- i2c@30a40000 simple_bus [ ] `-- regulators => i2c dev 0 Setting bus to 0 => i2c probe Valid chip addresses: 08 50 => i2c md 8 31 0031: 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 Signed-off-by: Peng Fan <Peng.Fan@freescale.com> Acked-by: Simon Glass <sjg@chromium.org>
2015-05-14 23:29:12 +00:00
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
#ifdef I2C4_BASE_ADDR
(void *)I2C4_BASE_ADDR,
#endif
};
/* i2c_index can be from 0 - 3 */
int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
struct i2c_pads_info *p)
{
char name[9];
int ret;
if (i2c_index >= ARRAY_SIZE(i2c_bases))
return -EINVAL;
snprintf(name, sizeof(name), "i2c_sda%01d", i2c_index);
ret = gpio_request(p->sda.gp, name);
if (ret)
return ret;
snprintf(name, sizeof(name), "i2c_scl%01d", i2c_index);
ret = gpio_request(p->scl.gp, name);
if (ret)
goto err_req;
/* Enable i2c clock */
ret = enable_i2c_clk(1, i2c_index);
if (ret)
goto err_clk;
/* Make sure bus is idle */
ret = force_idle_bus(p);
if (ret)
goto err_idle;
i2c: mxc: refactor i2c driver and support dm 1. Introduce a new structure `struct mxc_i2c_bus`, this structure will used for non-DM and DM. 2. Remove `struct mxc_i2c_regs` structure, but use register offset to access registers based on `base` entry of `struct mxc_i2c_bus`. 3. Remove most `#ifdef I2C_QUIRK_REG`. Using driver_data to contain platform flags. A new flag is introduced, I2C_QUIRK_FLAG. 4. Most functions use `struct mxc_i2c_bus` as one of the parameters. Make most functions common to DM and non-DM, try to avoid duplicated code. 5. Support DM, but pinctrl is not included. Pinmux setting is still set by setup_i2c, but we do not need bus_i2c_init for DM. 6. struct i2c_parms and struct sram_data are removed. 7. Remove bus_i2c_read bus_i2c_write prototype in header file. The frist paramter of bus_i2c_init is modified to i2c index. Add new prototype i2c_idle_bus and force_bus_idle. Since bus_i2c_init is not good for DM I2C and pinctrl is missed, we use a weak function for i2c_idle_bus. Board file take the responsibility to implement this function, like this: " int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus) { if (i2c_bus->index == 0) force_bus_idle(i2c_pads_info0); else if (i2c_bus->index == 1) force_bus_idle(i2c_pads_info1); else xxxxxx } " 8. Introduce a weak function, enable_i2c_clk 9. Tested on an i.MX7 platform. Log info: => dm tree Class Probed Name ---------------------------------------- root [ + ] root_driver simple_bus [ ] |-- soc simple_bus [ ] | |-- aips-bus@30000000 simple_bus [ ] | | |-- anatop@30360000 simple_bus [ ] | | `-- snvs@30370000 simple_bus [ ] | |-- aips-bus@30400000 simple_bus [ ] | `-- aips-bus@30800000 i2c [ ] | |-- i2c@30a20000 i2c [ ] | `-- i2c@30a40000 simple_bus [ ] `-- regulators => i2c dev 0 Setting bus to 0 => i2c probe Valid chip addresses: 08 50 => i2c md 8 31 0031: 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 Signed-off-by: Peng Fan <Peng.Fan@freescale.com> Acked-by: Simon Glass <sjg@chromium.org>
2015-05-14 23:29:12 +00:00
#ifndef CONFIG_DM_I2C
bus_i2c_init(i2c_index, speed, slave_addr, force_idle_bus, p);
#endif
return 0;
err_idle:
err_clk:
gpio_free(p->scl.gp);
err_req:
gpio_free(p->sda.gp);
return ret;
}