/* * linux/arch/arm/plat-omap/i2c.c * * Helper module for board specific I2C bus registration * * Copyright (C) 2007 Nokia Corporation. * * Contact: Jarkko Nikula * * 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 #include #include #include #include #include #include #include #include #include #include #include #define OMAP_I2C_SIZE 0x3f #define OMAP1_I2C_BASE 0xfffb3800 static const char name[] = "i2c_omap"; #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); } /* * 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, }, }; #ifdef CONFIG_ARCH_OMAP2PLUS 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); }