diff options
Diffstat (limited to 'kernel/arch/arm/plat-omap/i2c.c')
-rw-r--r-- | kernel/arch/arm/plat-omap/i2c.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/kernel/arch/arm/plat-omap/i2c.c b/kernel/arch/arm/plat-omap/i2c.c new file mode 100644 index 000000000..58213d971 --- /dev/null +++ b/kernel/arch/arm/plat-omap/i2c.c @@ -0,0 +1,116 @@ +/* + * 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 <plat/i2c.h> + +#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); +} |