u-boot/arch/arm/imx-common/i2c-mxv7.c
Peng Fan 71204e95ce 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 18:49:36 -06:00

115 lines
2.4 KiB
C

/*
* 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>
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 */
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;
#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;
}