1 /* 2 * Helper module for board specific I2C bus registration 3 * 4 * Copyright (C) 2009 Nokia Corporation. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * version 2 as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 18 * 02110-1301 USA 19 * 20 */ 21 22 #include <linux/i2c.h> 23 #include <linux/i2c-omap.h> 24 #include <mach/mux.h> 25 #include "soc.h" 26 27 #include <plat/i2c.h> 28 29 #define OMAP_I2C_SIZE 0x3f 30 #define OMAP1_I2C_BASE 0xfffb3800 31 32 static const char name[] = "omap_i2c"; 33 34 static struct resource i2c_resources[2] = { 35 }; 36 37 static struct platform_device omap_i2c_devices[1] = { 38 }; 39 40 static void __init omap1_i2c_mux_pins(int bus_id) 41 { 42 if (cpu_is_omap7xx()) { 43 omap_cfg_reg(I2C_7XX_SDA); 44 omap_cfg_reg(I2C_7XX_SCL); 45 } else { 46 omap_cfg_reg(I2C_SDA); 47 omap_cfg_reg(I2C_SCL); 48 } 49 } 50 51 int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *pdata, 52 int bus_id) 53 { 54 struct platform_device *pdev; 55 struct resource *res; 56 57 if (bus_id > 1) 58 return -EINVAL; 59 60 omap1_i2c_mux_pins(bus_id); 61 62 pdev = &omap_i2c_devices[bus_id - 1]; 63 pdev->id = bus_id; 64 pdev->name = name; 65 pdev->num_resources = ARRAY_SIZE(i2c_resources); 66 res = i2c_resources; 67 res[0].start = OMAP1_I2C_BASE; 68 res[0].end = res[0].start + OMAP_I2C_SIZE; 69 res[0].flags = IORESOURCE_MEM; 70 res[1].start = INT_I2C; 71 res[1].flags = IORESOURCE_IRQ; 72 pdev->resource = res; 73 74 /* all OMAP1 have IP version 1 register set */ 75 pdata->rev = OMAP_I2C_IP_VERSION_1; 76 77 /* all OMAP1 I2C are implemented like this */ 78 pdata->flags = OMAP_I2C_FLAG_NO_FIFO | 79 OMAP_I2C_FLAG_SIMPLE_CLOCK | 80 OMAP_I2C_FLAG_16BIT_DATA_REG | 81 OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK; 82 83 /* how the cpu bus is wired up differs for 7xx only */ 84 85 if (cpu_is_omap7xx()) 86 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_1; 87 else 88 pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2; 89 90 pdev->dev.platform_data = pdata; 91 92 return platform_device_register(pdev); 93 } 94 95 #define OMAP_I2C_MAX_CONTROLLERS 4 96 static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS]; 97 98 #define OMAP_I2C_CMDLINE_SETUP (BIT(31)) 99 100 /** 101 * omap_i2c_bus_setup - Process command line options for the I2C bus speed 102 * @str: String of options 103 * 104 * This function allow to override the default I2C bus speed for given I2C 105 * bus with a command line option. 106 * 107 * Format: i2c_bus=bus_id,clkrate (in kHz) 108 * 109 * Returns 1 on success, 0 otherwise. 110 */ 111 static int __init omap_i2c_bus_setup(char *str) 112 { 113 int ints[3]; 114 115 get_options(str, 3, ints); 116 if (ints[0] < 2 || ints[1] < 1 || 117 ints[1] > OMAP_I2C_MAX_CONTROLLERS) 118 return 0; 119 i2c_pdata[ints[1] - 1].clkrate = ints[2]; 120 i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP; 121 122 return 1; 123 } 124 __setup("i2c_bus=", omap_i2c_bus_setup); 125 126 /* 127 * Register busses defined in command line but that are not registered with 128 * omap_register_i2c_bus from board initialization code. 129 */ 130 int __init omap_register_i2c_bus_cmdline(void) 131 { 132 int i, err = 0; 133 134 for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++) 135 if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) { 136 i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP; 137 err = omap_i2c_add_bus(&i2c_pdata[i], i + 1); 138 if (err) 139 goto out; 140 } 141 142 out: 143 return err; 144 } 145 146 /** 147 * omap_register_i2c_bus - register I2C bus with device descriptors 148 * @bus_id: bus id counting from number 1 149 * @clkrate: clock rate of the bus in kHz 150 * @info: pointer into I2C device descriptor table or NULL 151 * @len: number of descriptors in the table 152 * 153 * Returns 0 on success or an error code. 154 */ 155 int __init omap_register_i2c_bus(int bus_id, u32 clkrate, 156 struct i2c_board_info const *info, 157 unsigned len) 158 { 159 int err; 160 161 BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS); 162 163 if (info) { 164 err = i2c_register_board_info(bus_id, info, len); 165 if (err) 166 return err; 167 } 168 169 if (!i2c_pdata[bus_id - 1].clkrate) 170 i2c_pdata[bus_id - 1].clkrate = clkrate; 171 172 i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP; 173 174 return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id); 175 } 176 177 static int __init omap_i2c_cmdline(void) 178 { 179 return omap_register_i2c_bus_cmdline(); 180 } 181 subsys_initcall(omap_i2c_cmdline); 182