/*
* linux/arch/arm/plat-omap/i2c.c
*
* Helper module for board specific I2C bus registration
*
* Copyright (C) 2007 Nokia Corporation.
*
* Contact: Jarkko Nikula <jhnikula@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/i2c-omap.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <mach/irqs.h>
#include <plat/mux.h>
#include <plat/i2c.h>
#include <plat/omap-pm.h>
#include <plat/omap_device.h>
#define OMAP_I2C_SIZE 0x3f
#define OMAP1_I2C_BASE 0xfffb3800
static const char name[] = "omap_i2c";
#define I2C_RESOURCE_BUILDER(base, irq) \
{ \
.start = (base), \
.end = (base) + OMAP_I2C_SIZE, \
.flags = IORESOURCE_MEM, \
}, \
{ \
.start = (irq), \
.flags = IORESOURCE_IRQ, \
},
static struct resource i2c_resources[][2] = {
{ I2C_RESOURCE_BUILDER(0, 0) },
};
#define I2C_DEV_BUILDER(bus_id, res, data) \
{ \
.id = (bus_id), \
.name = name, \
.num_resources = ARRAY_SIZE(res), \
.resource = (res), \
.dev = { \
.platform_data = (data), \
}, \
}
#define MAX_OMAP_I2C_HWMOD_NAME_LEN 16
#define OMAP_I2C_MAX_CONTROLLERS 4
static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
static struct platform_device omap_i2c_devices[] = {
I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_pdata[0]),
};
#define OMAP_I2C_CMDLINE_SETUP (BIT(31))
static int __init omap_i2c_nr_ports(void)
{
int ports = 0;
if (cpu_class_is_omap1())
ports = 1;
else if (cpu_is_omap24xx())
ports = 2;
else if (cpu_is_omap34xx())
ports = 3;
else if (cpu_is_omap44xx())
ports = 4;
return ports;
}
static inline int omap1_i2c_add_bus(int bus_id)
{
struct platform_device *pdev;
struct omap_i2c_bus_platform_data *pdata;
struct resource *res;
omap1_i2c_mux_pins(bus_id);
pdev = &omap_i2c_devices[bus_id - 1];
res = pdev->resource;
res[0].start = OMAP1_I2C_BASE;
res[0].end = res[0].start + OMAP_I2C_SIZE;
res[1].start = INT_I2C;
pdata = &i2c_pdata[bus_id - 1];
return platform_device_register(pdev);
}
#ifdef CONFIG_ARCH_OMAP2PLUS
/*
* XXX This function is a temporary compatibility wrapper - only
* needed until the I2C driver can be converted to call
* omap_pm_set_max_dev_wakeup_lat() and handle a return code.
*/
static void omap_pm_set_max_mpu_wakeup_lat_compat(struct device *dev, long t)
{
omap_pm_set_max_mpu_wakeup_lat(dev, t);
}
static struct omap_device_pm_latency omap_i2c_latency[] = {
[0] = {
.deactivate_func = omap_device_idle_hwmods,
.activate_func = omap_device_enable_hwmods,
.flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
},
};
static inline int omap2_i2c_add_bus(int bus_id)
{
int l;
struct omap_hwmod *oh;
struct omap_device *od;
char oh_name[MAX_OMAP_I2C_HWMOD_NAME_LEN];
struct omap_i2c_bus_platform_data *pdata;
omap2_i2c_mux_pins(bus_id);
l = snprintf(oh_name, MAX_OMAP_I2C_HWMOD_NAME_LEN, "i2c%d", bus_id);
WARN(l >= MAX_OMAP_I2C_HWMOD_NAME_LEN,
"String buffer overflow in I2C%d device setup\n", bus_id);
oh = omap_hwmod_lookup(oh_name);
if (!oh) {
pr_err("Could not look up %s\n", oh_name);
return -EEXIST;
}
pdata = &i2c_pdata[bus_id - 1];
/*
* When waiting for completion of a i2c transfer, we need to
* set a wake up latency constraint for the MPU. This is to
* ensure quick enough wakeup from idle, when transfer
* completes.
* Only omap3 has support for constraints
*/
if (cpu_is_omap34xx())
pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat;
od = omap_device_build(name, bus_id, oh, pdata,
sizeof(struct omap_i2c_bus_platform_data),
omap_i2c_latency, ARRAY_SIZE(omap_i2c_latency), 0);
WARN(IS_ERR(od), "Could not build omap_device for %s\n", name);
return PTR_ERR(od);
}
#else
static inline int omap2_i2c_add_bus(int bus_id)
{
return 0;
}
#endif
static int __init omap_i2c_add_bus(int bus_id)
{
if (cpu_class_is_omap1())
return omap1_i2c_add_bus(bus_id);
else
return omap2_i2c_add_bus(bus_id);
}
/**
* 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 ports;
int ints[3];
ports = omap_i2c_nr_ports();
get_options(str, 3, ints);
if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
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.
*/
static 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(i + 1);
if (err)
goto out;
}
out:
return err;
}
subsys_initcall(omap_register_i2c_bus_cmdline);
/**
* 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_nr_ports());
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(bus_id);
}
