hwmon: (sht15) Root out platform data

After finding out there are active users of this sensor I noticed:

- It has a single PXA27x board file using the platform data
- The platform data is only used to carry two GPIO pins, all other
  fields are unused
- The driver does not use GPIO descriptors but the legacy GPIO
  API

I saw we can swiftly fix this by:

- Killing off the platform data entirely
- Define a GPIO descriptor lookup table in the board file
- Use the standard devm_gpiod_get() to grab the GPIO descriptors
  from either the device tree or the board file table.

This compiles, but needs testing.

Cc: arm@kernel.org
Cc: Marco Franchi <marco.franchi@nxp.com>
Cc: Davide Hug <d@videhug.ch>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Marco Franchi <marco.franchi@nxp.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/sht15

@@ -42,8 +42,7 @@ chip. These coefficients are used to internally calibrate the signals from the
 sensors. Disabling the reload of those coefficients allows saving 10ms for each
 measurement and decrease power consumption, while losing on precision.
 
-Some options may be set directly in the sht15_platform_data structure
-or via sysfs attributes.
+Some options may be set via sysfs attributes.
 
 Notes:
   * The regulator supply name is set to "vcc".

arch/arm/mach-pxa/stargate2.c

@@ -29,6 +29,7 @@
 #include <linux/platform_data/pcf857x.h>
 #include <linux/platform_data/at24.h>
 #include <linux/smc91x.h>
+#include <linux/gpio/machine.h>
 #include <linux/gpio.h>
 #include <linux/leds.h>
 
@@ -52,7 +53,6 @@
 #include <linux/spi/spi.h>
 #include <linux/spi/pxa2xx_spi.h>
 #include <linux/mfd/da903x.h>
-#include <linux/platform_data/sht15.h>
 
 #include "devices.h"
 #include "generic.h"
@@ -137,17 +137,18 @@ static unsigned long sg2_im2_unified_pin_config[] __initdata = {
 	GPIO10_GPIO, /* large basic connector pin 23 */
 };
 
-static struct sht15_platform_data platform_data_sht15 = {
-	.gpio_data =  100,
-	.gpio_sck  =  98,
+static struct gpiod_lookup_table sht15_gpiod_table = {
+	.dev_id = "sht15",
+	.table = {
+		/* FIXME: should this have |GPIO_OPEN_DRAIN set? */
+		GPIO_LOOKUP("gpio-pxa", 100, "data", GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("gpio-pxa", 98, "clk", GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct platform_device sht15 = {
 	.name = "sht15",
 	.id = -1,
-	.dev = {
-		.platform_data = &platform_data_sht15,
-	},
 };
 
 static struct regulator_consumer_supply stargate2_sensor_3_con[] = {
@@ -608,6 +609,7 @@ static void __init imote2_init(void)
 
 	imote2_stargate2_init();
 
+	gpiod_add_lookup_table(&sht15_gpiod_table);
 	platform_add_devices(imote2_devices, ARRAY_SIZE(imote2_devices));
 
 	i2c_register_board_info(0, imote2_i2c_board_info,
@@ -988,6 +990,7 @@ static void __init stargate2_init(void)
 
 	imote2_stargate2_init();
 
+	gpiod_add_lookup_table(&sht15_gpiod_table);
 	platform_add_devices(ARRAY_AND_SIZE(stargate2_devices));
 
 	i2c_register_board_info(0, ARRAY_AND_SIZE(stargate2_i2c_board_info));

include/linux/platform_data/sht15.h

-/*
- * sht15.h - support for the SHT15 Temperature and Humidity Sensor
- *
- * Copyright (c) 2009 Jonathan Cameron
- *
- * Copyright (c) 2007 Wouter Horre
- *
- * 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.
- *
- * For further information, see the Documentation/hwmon/sht15 file.
- */
-
-#ifndef _PDATA_SHT15_H
-#define _PDATA_SHT15_H
-
-/**
- * struct sht15_platform_data - sht15 connectivity info
- * @gpio_data:		no. of gpio to which bidirectional data line is
- *			connected.
- * @gpio_sck:		no. of gpio to which the data clock is connected.
- * @supply_mv:		supply voltage in mv. Overridden by regulator if
- *			available.
- * @checksum:		flag to indicate the checksum should be validated.
- * @no_otp_reload:	flag to indicate no reload from OTP.
- * @low_resolution:	flag to indicate the temp/humidity resolution to use.
- */
-struct sht15_platform_data {
-	int gpio_data;
-	int gpio_sck;
-	int supply_mv;
-	bool checksum;
-	bool no_otp_reload;
-	bool low_resolution;
-};
-
-#endif /* _PDATA_SHT15_H */