From 705e0984444bc7109c5686c36333b27119d8a888 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Fri, 21 Jan 2011 10:56:16 +0530 Subject: mach-ux500: dynamic UIB (user interface boards) detection Add support for dynamic detection of the UIB used (at the cost of one i2c error on the lesser-used UIB) and also provide an override via a command line parameter if needed. Signed-off-by: Rabin Vincent Signed-off-by: Sundar Iyer Signed-off-by: Linus Walleij --- arch/arm/mach-ux500/board-mop500-uib.c | 135 +++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 arch/arm/mach-ux500/board-mop500-uib.c (limited to 'arch/arm/mach-ux500/board-mop500-uib.c') diff --git a/arch/arm/mach-ux500/board-mop500-uib.c b/arch/arm/mach-ux500/board-mop500-uib.c new file mode 100644 index 000000000000..69cce41f602a --- /dev/null +++ b/arch/arm/mach-ux500/board-mop500-uib.c @@ -0,0 +1,135 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * + * Author: Rabin Vincent for ST-Ericsson + * License terms: GNU General Public License (GPL), version 2 + */ + +#define pr_fmt(fmt) "mop500-uib: " fmt + +#include +#include +#include + +#include +#include "board-mop500.h" + +enum mop500_uib { + STUIB, + U8500UIB, +}; + +struct uib { + const char *name; + const char *option; + void (*init)(void); +}; + +static struct __initdata uib mop500_uibs[] = { + [STUIB] = { + .name = "ST-UIB", + .option = "stuib", + .init = mop500_stuib_init, + }, + [U8500UIB] = { + .name = "U8500-UIB", + .option = "u8500uib", + .init = mop500_u8500uib_init, + }, +}; + +static struct uib *mop500_uib; + +static int __init mop500_uib_setup(char *str) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(mop500_uibs); i++) { + struct uib *uib = &mop500_uibs[i]; + + if (!strcmp(str, uib->option)) { + mop500_uib = uib; + break; + } + } + + if (i == ARRAY_SIZE(mop500_uibs)) + pr_err("invalid uib= option (%s)\n", str); + + return 1; +} +__setup("uib=", mop500_uib_setup); + +/* + * The UIBs are detected after the I2C host controllers are registered, so + * i2c_register_board_info() can't be used. + */ +void mop500_uib_i2c_add(int busnum, struct i2c_board_info *info, + unsigned n) +{ + struct i2c_adapter *adap; + struct i2c_client *client; + int i; + + adap = i2c_get_adapter(busnum); + if (!adap) { + pr_err("failed to get adapter i2c%d\n", busnum); + return; + } + + for (i = 0; i < n; i++) { + client = i2c_new_device(adap, &info[i]); + if (!client) + pr_err("failed to register %s to i2c%d\n", + info[i].type, busnum); + } + + i2c_put_adapter(adap); +} + +static void __init __mop500_uib_init(struct uib *uib, const char *why) +{ + pr_info("%s (%s)\n", uib->name, why); + uib->init(); +} + +/* + * Detect the UIB attached based on the presence or absence of i2c devices. + */ +static int __init mop500_uib_init(void) +{ + struct uib *uib = mop500_uib; + struct i2c_adapter *i2c0; + int ret; + + if (!cpu_is_u8500()) + return -ENODEV; + + if (uib) { + __mop500_uib_init(uib, "from uib= boot argument"); + return 0; + } + + i2c0 = i2c_get_adapter(0); + if (!i2c0) { + __mop500_uib_init(&mop500_uibs[STUIB], + "fallback, could not get i2c0"); + return -ENODEV; + } + + /* U8500-UIB has the TC35893 at 0x44 on I2C0, the ST-UIB doesn't. */ + ret = i2c_smbus_xfer(i2c0, 0x44, 0, I2C_SMBUS_WRITE, 0, + I2C_SMBUS_QUICK, NULL); + i2c_put_adapter(i2c0); + + if (ret == 0) + uib = &mop500_uibs[U8500UIB]; + else + uib = &mop500_uibs[STUIB]; + + __mop500_uib_init(uib, "detected"); + + return 0; +} + +module_init(mop500_uib_init); -- cgit v1.2.3