linuxdebug/arch/arm/mach-omap1/i2c.c

168 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Helper module for board specific I2C bus registration
*
* Copyright (C) 2009 Nokia Corporation.
*/
#include <linux/i2c.h>
#include <linux/platform_data/i2c-omap.h>
#include "mux.h"
#include "soc.h"
#include "i2c.h"
#define OMAP_I2C_SIZE 0x3f
#define OMAP1_I2C_BASE 0xfffb3800
static const char name[] = "omap_i2c";
static struct resource i2c_resources[2] = {
};
static struct platform_device omap_i2c_devices[1] = {
};
static void __init omap1_i2c_mux_pins(int bus_id)
{
if (cpu_is_omap7xx()) {
omap_cfg_reg(I2C_7XX_SDA);
omap_cfg_reg(I2C_7XX_SCL);
} else {
omap_cfg_reg(I2C_SDA);
omap_cfg_reg(I2C_SCL);
}
}
int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *pdata,
int bus_id)
{
struct platform_device *pdev;
struct resource *res;
if (bus_id > 1)
return -EINVAL;
omap1_i2c_mux_pins(bus_id);
pdev = &omap_i2c_devices[bus_id - 1];
pdev->id = bus_id;
pdev->name = name;
pdev->num_resources = ARRAY_SIZE(i2c_resources);
res = i2c_resources;
res[0].start = OMAP1_I2C_BASE;
res[0].end = res[0].start + OMAP_I2C_SIZE;
res[0].flags = IORESOURCE_MEM;
res[1].start = INT_I2C;
res[1].flags = IORESOURCE_IRQ;
pdev->resource = res;
/* all OMAP1 have IP version 1 register set */
pdata->rev = OMAP_I2C_IP_VERSION_1;
/* all OMAP1 I2C are implemented like this */
pdata->flags = OMAP_I2C_FLAG_NO_FIFO |
OMAP_I2C_FLAG_SIMPLE_CLOCK |
OMAP_I2C_FLAG_16BIT_DATA_REG |
OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;
/* how the cpu bus is wired up differs for 7xx only */
if (cpu_is_omap7xx())
pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_1;
else
pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2;
pdev->dev.platform_data = pdata;
return platform_device_register(pdev);
}
#define OMAP_I2C_MAX_CONTROLLERS 4
static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
#define OMAP_I2C_CMDLINE_SETUP (BIT(31))
/**
* omap_i2c_bus_setup - Process command line options for the I2C bus speed
* @str: String of options
*
* This function allow to override the default I2C bus speed for given I2C
* bus with a command line option.
*
* Format: i2c_bus=bus_id,clkrate (in kHz)
*
* Returns 1 on success, 0 otherwise.
*/
static int __init omap_i2c_bus_setup(char *str)
{
int ints[3];
get_options(str, 3, ints);
if (ints[0] < 2 || ints[1] < 1 ||
ints[1] > OMAP_I2C_MAX_CONTROLLERS)
return 0;
i2c_pdata[ints[1] - 1].clkrate = ints[2];
i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
return 1;
}
__setup("i2c_bus=", omap_i2c_bus_setup);
/*
* Register busses defined in command line but that are not registered with
* omap_register_i2c_bus from board initialization code.
*/
int __init omap_register_i2c_bus_cmdline(void)
{
int i, err = 0;
for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
if (err)
goto out;
}
out:
return err;
}
/**
* omap_register_i2c_bus - register I2C bus with device descriptors
* @bus_id: bus id counting from number 1
* @clkrate: clock rate of the bus in kHz
* @info: pointer into I2C device descriptor table or NULL
* @len: number of descriptors in the table
*
* Returns 0 on success or an error code.
*/
int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
struct i2c_board_info const *info,
unsigned len)
{
int err;
BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS);
if (info) {
err = i2c_register_board_info(bus_id, info, len);
if (err)
return err;
}
if (!i2c_pdata[bus_id - 1].clkrate)
i2c_pdata[bus_id - 1].clkrate = clkrate;
i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
}
static int __init omap_i2c_cmdline(void)
{
return omap_register_i2c_bus_cmdline();
}
subsys_initcall(omap_i2c_cmdline);