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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/plat-omap/i2c.c
Initial import
Diffstat (limited to 'arch/arm/plat-omap/i2c.c')
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diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
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+/*
+ * 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);
+}