i2c: gpio: Convert to use descriptors

This converts the GPIO-based I2C-driver to using GPIO
descriptors instead of the old global numberspace-based
GPIO interface. We:

- Convert the driver to unconditionally grab two GPIOs
from the device by index 0 (SDA) and 1 (SCL) which
will work fine with device tree and descriptor tables.
The existing device trees will continue to work just
like before, but without any roundtrip through the
global numberspace.

- Brutally convert all boardfiles still passing global
GPIOs by registering descriptor tables associated with
the devices instead so this driver does not need to keep
supporting passing any GPIO numbers as platform data.

There is no stepwise approach as elegant as this, I
strongly prefer this big hammer over any antsteps for this
conversion. This way the old GPIO numbers go away and
NEVER COME BACK.

Special conversion for the different boards utilizing
I2C-GPIO:

- EP93xx (arch/arm/mach-ep93xx): pretty straight forward as
all boards were using the same two GPIO lines, just define
these two in a lookup table for "i2c-gpio" and register
these along with the device. None of them define any
other platform data so just pass NULL as platform data.
This platform selects GPIOLIB so all should be smooth.
The pins appear on a gpiochip for bank "G" as pins 1 (SDA)
and 0 (SCL).

- IXP4 (arch/arm/mach-ixp4): descriptor tables have to
be registered for each board separately. They all use
"IXP4XX_GPIO_CHIP" so it is pretty straight forward.
Most board define no other platform data than SCL/SDA
so they can drop the #include of <linux/i2c-gpio.h> and
assign NULL to platform data.

The "goramo_mlr" (Goramo Multilink Router) board is a bit
worrisome: it implements its own I2C bit-banging in the
board file, and optionally registers an I2C serial port,
but claims the same GPIO lines for itself in the board file.
This is not going to work: there will be competition for the
GPIO lines, so delete the optional extra I2C bus instead, no
I2C devices are registered on it anyway, there are just hints
that it may contain an EEPROM that may be accessed from
userspace. This needs to be fixed up properly by the serial
clock using I2C emulation so drop a note in the code.

- KS8695 board acs5k (arch/arm/mach-ks8695/board-acs5.c)
has some platform data in addition to the pins so it needs to
be kept around sans GPIO lines. Its GPIO chip is named
"KS8695" and the arch selects GPIOLIB.

- PXA boards (arch/arm/mach-pxa/*) use some of the platform
data so it needs to be preserved here. The viper board even
registers two GPIO I2Cs. The gpiochip is named "gpio-pxa" and
the arch selects GPIOLIB.

- SA1100 Simpad (arch/arm/mach-sa1100/simpad.c) defines a GPIO
I2C bus, and the arch selects GPIOLIB.

- Blackfin boards (arch/blackfin/bf533 etc) for these I assume
their I2C GPIOs refer to the local gpiochip defined in
arch/blackfin/kernel/bfin_gpio.c names "BFIN-GPIO".
The arch selects GPIOLIB. The boards get spiked with
IF_ENABLED(I2C_GPIO) but that is a side effect of it
being like that already (I would just have Kconfig select
I2C_GPIO and get rid of them all.) I also delete any
platform data set to 0 as it will get that value anyway
from static declartions of platform data.

- The MIPS selects GPIOLIB and the Alchemy machine is using
two local GPIO chips, one of them has a GPIO I2C. We need
to adjust the local offset from the global number space here.
The ATH79 has a proper GPIO driver in drivers/gpio/gpio-ath79.c
and AFAICT the chip is named "ath79-gpio" and the PB44
PCF857x expander spawns from this on GPIO 1 and 0. The latter
board only use the platform data to specify pins so it can be
cut altogether after this.

- The MFD Silicon Motion SM501 is a special case. It dynamically
spawns an I2C bus off the MFD using sm501_create_subdev().
We use an approach to dynamically create a machine descriptor
table and attach this to the "SM501-LOW" or "SM501-HIGH"
gpiochip. We use chip-local offsets to grab the right lines.
We can get rid of two local static inline helpers as part
of this refactoring.

Cc: Steven Miao <[e-mail]>
Cc: Ralf Baechle <[e-mail]>
Cc: Guenter Roeck <[e-mail]>
Cc: Ville Syrjälä <[e-mail]>
Cc: Magnus Damm <[e-mail]>
Cc: Ben Dooks <[e-mail]>
Cc: Heiko Schocher <[e-mail]>
Acked-by: Wu, Aaron <[e-mail]>
Acked-by: Olof Johansson <[e-mail]>
Acked-by: Lee Jones <[e-mail]>
Acked-by: Ralf Baechle <[e-mail]>
Tested-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

arch/arm/mach-ep93xx/core.c

···
 #include <linux/amba/serial.h>
 #include <linux/mtd/physmap.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/spi/spi.h>
 #include <linux/export.h>
 #include <linux/irqchip/arm-vic.h>
···
 /*************************************************************************
  * EP93xx i2c peripheral handling
  *************************************************************************/
-static struct i2c_gpio_platform_data ep93xx_i2c_data;
+
+/* All EP93xx devices use the same two GPIO pins for I2C bit-banging */
+static struct gpiod_lookup_table ep93xx_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		/* Use local offsets on gpiochip/port "G" */
+		GPIO_LOOKUP_IDX("G", 1, NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("G", 0, NULL, 1, GPIO_ACTIVE_HIGH),
+	},
+};
 
 static struct platform_device ep93xx_i2c_device = {
 	.name		= "i2c-gpio",
 	.id		= 0,
 	.dev		= {
-		.platform_data	= &ep93xx_i2c_data,
+		.platform_data	= NULL,
 	},
 };
 
 /**
  * ep93xx_register_i2c - Register the i2c platform device.
- * @data:	platform specific i2c-gpio configuration (__initdata)
  * @devices:	platform specific i2c bus device information (__initdata)
  * @num:	the number of devices on the i2c bus
  */
-void __init ep93xx_register_i2c(struct i2c_gpio_platform_data *data,
-				struct i2c_board_info *devices, int num)
+void __init ep93xx_register_i2c(struct i2c_board_info *devices, int num)
 {
 	/*
-	 * Set the EEPROM interface pin drive type control.
-	 * Defines the driver type for the EECLK and EEDAT pins as either
-	 * open drain, which will require an external pull-up, or a normal
-	 * CMOS driver.
+	 * FIXME: this just sets the two pins as non-opendrain, as no
+	 * platforms tries to do that anyway. Flag the applicable lines
+	 * as open drain in the GPIO_LOOKUP above and the driver or
+	 * gpiolib will handle open drain/open drain emulation as need
+	 * be. Right now i2c-gpio emulates open drain which is not
+	 * optimal.
 	 */
-	if (data->sda_is_open_drain && data->sda_pin != EP93XX_GPIO_LINE_EEDAT)
-		pr_warning("sda != EEDAT, open drain has no effect\n");
-	if (data->scl_is_open_drain && data->scl_pin != EP93XX_GPIO_LINE_EECLK)
-		pr_warning("scl != EECLK, open drain has no effect\n");
-
-	__raw_writel((data->sda_is_open_drain << 1) |
-		     (data->scl_is_open_drain << 0),
+	__raw_writel((0 << 1) | (0 << 0),
 		     EP93XX_GPIO_EEDRIVE);
 
-	ep93xx_i2c_data = *data;
 	i2c_register_board_info(0, devices, num);
+	gpiod_add_lookup_table(&ep93xx_i2c_gpiod_table);
 	platform_device_register(&ep93xx_i2c_device);
 }
 

arch/arm/mach-ep93xx/edb93xx.c

···
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
 #include <linux/spi/spi.h>
 
 #include <sound/cs4271.h>
···
 /*************************************************************************
  * EDB93xx i2c peripheral handling
  *************************************************************************/
-static struct i2c_gpio_platform_data __initdata edb93xx_i2c_gpio_data = {
-	.sda_pin		= EP93XX_GPIO_LINE_EEDAT,
-	.sda_is_open_drain	= 0,
-	.scl_pin		= EP93XX_GPIO_LINE_EECLK,
-	.scl_is_open_drain	= 0,
-	.udelay			= 0,	/* default to 100 kHz */
-	.timeout		= 0,	/* default to 100 ms */
-};
 
 static struct i2c_board_info __initdata edb93xxa_i2c_board_info[] = {
 	{
···
 {
 	if (machine_is_edb9302a() || machine_is_edb9307a() ||
 	    machine_is_edb9315a()) {
-		ep93xx_register_i2c(&edb93xx_i2c_gpio_data,
-				    edb93xxa_i2c_board_info,
+		ep93xx_register_i2c(edb93xxa_i2c_board_info,
 				    ARRAY_SIZE(edb93xxa_i2c_board_info));
 	} else if (machine_is_edb9302() || machine_is_edb9307()
 		|| machine_is_edb9312() || machine_is_edb9315()) {
-		ep93xx_register_i2c(&edb93xx_i2c_gpio_data,
-				    edb93xx_i2c_board_info,
+		ep93xx_register_i2c(edb93xx_i2c_board_info,
 				    ARRAY_SIZE(edb93xx_i2c_board_info));
 	}
 }

arch/arm/mach-ep93xx/include/mach/platform.h

···
 #include <linux/reboot.h>
 
 struct device;
-struct i2c_gpio_platform_data;
 struct i2c_board_info;
 struct spi_board_info;
 struct platform_device;
···
 			   resource_size_t start, resource_size_t size);
 
 void ep93xx_register_eth(struct ep93xx_eth_data *data, int copy_addr);
-void ep93xx_register_i2c(struct i2c_gpio_platform_data *data,
-			 struct i2c_board_info *devices, int num);
+void ep93xx_register_i2c(struct i2c_board_info *devices, int num);
 void ep93xx_register_spi(struct ep93xx_spi_info *info,
 			 struct spi_board_info *devices, int num);
 void ep93xx_register_fb(struct ep93xxfb_mach_info *data);

arch/arm/mach-ep93xx/simone.c

···
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
 #include <linux/mmc/host.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/mmc_spi.h>
···
 	.use_dma = 1,
 };
 
-static struct i2c_gpio_platform_data __initdata simone_i2c_gpio_data = {
-	.sda_pin		= EP93XX_GPIO_LINE_EEDAT,
-	.sda_is_open_drain	= 0,
-	.scl_pin		= EP93XX_GPIO_LINE_EECLK,
-	.scl_is_open_drain	= 0,
-	.udelay			= 0,
-	.timeout		= 0,
-};
-
 static struct i2c_board_info __initdata simone_i2c_board_info[] = {
 	{
 		I2C_BOARD_INFO("ds1337", 0x68),
···
 	ep93xx_register_flash(2, EP93XX_CS6_PHYS_BASE, SZ_8M);
 	ep93xx_register_eth(&simone_eth_data, 1);
 	ep93xx_register_fb(&simone_fb_info);
-	ep93xx_register_i2c(&simone_i2c_gpio_data, simone_i2c_board_info,
+	ep93xx_register_i2c(simone_i2c_board_info,
 			    ARRAY_SIZE(simone_i2c_board_info));
 	ep93xx_register_spi(&simone_spi_info, simone_spi_devices,
 			    ARRAY_SIZE(simone_spi_devices));

arch/arm/mach-ep93xx/snappercl15.c

···
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
 #include <linux/fb.h>
 
 #include <linux/mtd/partitions.h>
···
 	.phy_id			= 1,
 };
 
-static struct i2c_gpio_platform_data __initdata snappercl15_i2c_gpio_data = {
-	.sda_pin		= EP93XX_GPIO_LINE_EEDAT,
-	.sda_is_open_drain	= 0,
-	.scl_pin		= EP93XX_GPIO_LINE_EECLK,
-	.scl_is_open_drain	= 0,
-	.udelay			= 0,
-	.timeout		= 0,
-};
-
 static struct i2c_board_info __initdata snappercl15_i2c_data[] = {
 	{
 		/* Audio codec */
···
 {
 	ep93xx_init_devices();
 	ep93xx_register_eth(&snappercl15_eth_data, 1);
-	ep93xx_register_i2c(&snappercl15_i2c_gpio_data, snappercl15_i2c_data,
+	ep93xx_register_i2c(snappercl15_i2c_data,
 			    ARRAY_SIZE(snappercl15_i2c_data));
 	ep93xx_register_fb(&snappercl15_fb_info);
 	snappercl15_register_audio();

arch/arm/mach-ep93xx/vision_ep9307.c

···
 #include <linux/io.h>
 #include <linux/mtd/partitions.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
 #include <linux/platform_data/pca953x.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/flash.h>
···
 /*************************************************************************
  * I2C Bus
  *************************************************************************/
-static struct i2c_gpio_platform_data vision_i2c_gpio_data __initdata = {
-	.sda_pin		= EP93XX_GPIO_LINE_EEDAT,
-	.scl_pin		= EP93XX_GPIO_LINE_EECLK,
-};
 
 static struct i2c_board_info vision_i2c_info[] __initdata = {
 	{
···
 
 	vision_i2c_info[1].irq = gpio_to_irq(EP93XX_GPIO_LINE_F(7));
 
-	ep93xx_register_i2c(&vision_i2c_gpio_data, vision_i2c_info,
+	ep93xx_register_i2c(vision_i2c_info,
 				ARRAY_SIZE(vision_i2c_info));
 	ep93xx_register_spi(&vision_spi_master, vision_spi_board_info,
 				ARRAY_SIZE(vision_spi_board_info));

arch/arm/mach-ixp4xx/avila-setup.c

···
 #include <linux/serial.h>
 #include <linux/tty.h>
 #include <linux/serial_8250.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <asm/types.h>
 #include <asm/setup.h>
 #include <asm/memory.h>
···
 	.resource	= &avila_flash_resource,
 };
 
-static struct i2c_gpio_platform_data avila_i2c_gpio_data = {
-	.sda_pin	= AVILA_SDA_PIN,
-	.scl_pin	= AVILA_SCL_PIN,
+static struct gpiod_lookup_table avila_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", AVILA_SDA_PIN,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", AVILA_SCL_PIN,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct platform_device avila_i2c_gpio = {
 	.name		= "i2c-gpio",
 	.id		= 0,
 	.dev	 = {
-		.platform_data	= &avila_i2c_gpio_data,
+		.platform_data	= NULL,
 	},
 };
 
···
 	avila_flash_resource.start = IXP4XX_EXP_BUS_BASE(0);
 	avila_flash_resource.end =
 		IXP4XX_EXP_BUS_BASE(0) + ixp4xx_exp_bus_size - 1;
+
+	gpiod_add_lookup_table(&avila_i2c_gpiod_table);
 
 	platform_add_devices(avila_devices, ARRAY_SIZE(avila_devices));
 

arch/arm/mach-ixp4xx/dsmg600-setup.c

···
 #include <linux/leds.h>
 #include <linux/reboot.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 
 #include <mach/hardware.h>
 
···
 	.resource		= &dsmg600_flash_resource,
 };
 
-static struct i2c_gpio_platform_data dsmg600_i2c_gpio_data = {
-	.sda_pin		= DSMG600_SDA_PIN,
-	.scl_pin		= DSMG600_SCL_PIN,
+static struct gpiod_lookup_table dsmg600_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", DSMG600_SDA_PIN,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", DSMG600_SCL_PIN,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct platform_device dsmg600_i2c_gpio = {
 	.name			= "i2c-gpio",
 	.id			= 0,
 	.dev	 = {
-		.platform_data	= &dsmg600_i2c_gpio_data,
+		.platform_data	= NULL,
 	},
 };
 
···
 	dsmg600_flash_resource.end =
 		IXP4XX_EXP_BUS_BASE(0) + ixp4xx_exp_bus_size - 1;
 
+	gpiod_add_lookup_table(&dsmg600_i2c_gpiod_table);
 	i2c_register_board_info(0, dsmg600_i2c_board_info,
 				ARRAY_SIZE(dsmg600_i2c_board_info));
 

arch/arm/mach-ixp4xx/fsg-setup.c

···
 #include <linux/leds.h>
 #include <linux/reboot.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/io.h>
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
···
 	.resource		= &fsg_flash_resource,
 };
 
-static struct i2c_gpio_platform_data fsg_i2c_gpio_data = {
-	.sda_pin		= FSG_SDA_PIN,
-	.scl_pin		= FSG_SCL_PIN,
+static struct gpiod_lookup_table fsg_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", FSG_SDA_PIN,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", FSG_SCL_PIN,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct platform_device fsg_i2c_gpio = {
 	.name			= "i2c-gpio",
 	.id			= 0,
 	.dev = {
-		.platform_data	= &fsg_i2c_gpio_data,
+		.platform_data	= NULL,
 	},
 };
 
···
 	/* Configure CS2 for operation, 8bit and writable */
 	*IXP4XX_EXP_CS2 = 0xbfff0002;
 
+	gpiod_add_lookup_table(&fsg_i2c_gpiod_table);
 	i2c_register_board_info(0, fsg_i2c_board_info,
 				ARRAY_SIZE(fsg_i2c_board_info));
 

arch/arm/mach-ixp4xx/goramo_mlr.c

···
 #include <linux/delay.h>
 #include <linux/gpio.h>
 #include <linux/hdlc.h>
-#include <linux/i2c-gpio.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
···
 static u32 hw_bits = 0xFFFFFFFD;    /* assume all hardware present */;
 static u8 control_value;
 
+/*
+ * FIXME: this is reimplementing I2C bit-bangining. Move this
+ * over to using driver/i2c/busses/i2c-gpio.c like all other boards
+ * and register proper I2C device(s) on the bus for this. (See
+ * other IXP4xx boards for examples.)
+ */
 static void set_scl(u8 value)
 {
 	gpio_set_value(GPIO_SCL, !!value);
···
 	.num_resources	= 1,
 	.resource	= &flash_resource,
 };
-
-
-/* I^2C interface */
-static struct i2c_gpio_platform_data i2c_data = {
-	.sda_pin	= GPIO_SDA,
-	.scl_pin	= GPIO_SCL,
-};
-
-static struct platform_device device_i2c = {
-	.name		= "i2c-gpio",
-	.id		= 0,
-	.dev		= { .platform_data = &i2c_data },
-};
-
 
 /* IXP425 2 UART ports */
 static struct resource uart_resources[] = {
···
 		device_tab[devices++] = &device_hss_tab[0]; /* max index 4 */
 	if (hw_bits & CFG_HW_HAS_HSS1)
 		device_tab[devices++] = &device_hss_tab[1]; /* max index 5 */
-
-	if (hw_bits & CFG_HW_HAS_EEPROM)
-		device_tab[devices++] = &device_i2c; /* max index 6 */
 
 	gpio_request(GPIO_SCL, "SCL/clock");
 	gpio_request(GPIO_SDA, "SDA/data");

arch/arm/mach-ixp4xx/ixdp425-setup.c

···
 #include <linux/serial.h>
 #include <linux/tty.h>
 #include <linux/serial_8250.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/io.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/rawnand.h>
···
 };
 #endif	/* CONFIG_MTD_NAND_PLATFORM */
 
-static struct i2c_gpio_platform_data ixdp425_i2c_gpio_data = {
-	.sda_pin	= IXDP425_SDA_PIN,
-	.scl_pin	= IXDP425_SCL_PIN,
+static struct gpiod_lookup_table ixdp425_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", IXDP425_SDA_PIN,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", IXDP425_SCL_PIN,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct platform_device ixdp425_i2c_gpio = {
 	.name		= "i2c-gpio",
 	.id		= 0,
 	.dev	 = {
-		.platform_data	= &ixdp425_i2c_gpio_data,
+		.platform_data	= NULL,
 	},
 };
 
···
 		ixdp425_uart_data[1].flags = 0;
 	}
 
+	gpiod_add_lookup_table(&ixdp425_i2c_gpiod_table);
 	platform_add_devices(ixdp425_devices, ARRAY_SIZE(ixdp425_devices));
 }
 

arch/arm/mach-ixp4xx/nas100d-setup.c

···
 #include <linux/leds.h>
 #include <linux/reboot.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/io.h>
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
···
 	.dev.platform_data	= &nas100d_led_data,
 };
 
-static struct i2c_gpio_platform_data nas100d_i2c_gpio_data = {
-	.sda_pin		= NAS100D_SDA_PIN,
-	.scl_pin		= NAS100D_SCL_PIN,
+static struct gpiod_lookup_table nas100d_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", NAS100D_SDA_PIN,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", NAS100D_SCL_PIN,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct platform_device nas100d_i2c_gpio = {
 	.name			= "i2c-gpio",
 	.id			= 0,
 	.dev	 = {
-		.platform_data	= &nas100d_i2c_gpio_data,
+		.platform_data	= NULL,
 	},
 };
 
···
 	nas100d_flash_resource.end =
 		IXP4XX_EXP_BUS_BASE(0) + ixp4xx_exp_bus_size - 1;
 
+	gpiod_add_lookup_table(&nas100d_i2c_gpiod_table);
 	i2c_register_board_info(0, nas100d_i2c_board_info,
 				ARRAY_SIZE(nas100d_i2c_board_info));
 

arch/arm/mach-ixp4xx/nslu2-setup.c

···
 #include <linux/leds.h>
 #include <linux/reboot.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/io.h>
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
···
 	.resource		= &nslu2_flash_resource,
 };
 
-static struct i2c_gpio_platform_data nslu2_i2c_gpio_data = {
-	.sda_pin		= NSLU2_SDA_PIN,
-	.scl_pin		= NSLU2_SCL_PIN,
+static struct gpiod_lookup_table nslu2_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", NSLU2_SDA_PIN,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("IXP4XX_GPIO_CHIP", NSLU2_SCL_PIN,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct i2c_board_info __initdata nslu2_i2c_board_info [] = {
···
 	.name			= "i2c-gpio",
 	.id			= 0,
 	.dev	 = {
-		.platform_data	= &nslu2_i2c_gpio_data,
+		.platform_data	= NULL,
 	},
 };
 
···
 	nslu2_flash_resource.end =
 		IXP4XX_EXP_BUS_BASE(0) + ixp4xx_exp_bus_size - 1;
 
+	gpiod_add_lookup_table(&nslu2_i2c_gpiod_table);
 	i2c_register_board_info(0, nslu2_i2c_board_info,
 				ARRAY_SIZE(nslu2_i2c_board_info));
 

arch/arm/mach-ks8695/board-acs5k.c

···
 #include <linux/interrupt.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
-
+#include <linux/gpio/machine.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 #include <linux/i2c-gpio.h>
···
 
 #include "generic.h"
 
+static struct gpiod_lookup_table acs5k_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("KS8695", 4, NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("KS8695", 5, NULL, 1, GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data acs5k_i2c_device_platdata = {
-	.sda_pin	= 4,
-	.scl_pin	= 5,
 	.udelay		= 10,
 };
 
···
 static void acs5k_i2c_init(void)
 {
 	/* The gpio interface */
+	gpiod_add_lookup_table(&acs5k_i2c_gpiod_table);
 	platform_device_register(&acs5k_i2c_device);
 	/* I2C devices */
 	i2c_register_board_info(0, acs5k_i2c_devs,

arch/arm/mach-pxa/palmz72.c

···
 #include <linux/power_supply.h>
 #include <linux/usb/gpio_vbus.h>
 #include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 
 #include <asm/mach-types.h>
 #include <asm/suspend.h>
···
 	.flags		= SOCAM_DATAWIDTH_8,
 };
 
+static struct gpiod_lookup_table palmz72_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("gpio-pxa", 118, NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("gpio-pxa", 117, NULL, 1, GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data palmz72_i2c_bus_data = {
-	.sda_pin	= 118,
-	.scl_pin	= 117,
 	.udelay		= 10,
 	.timeout	= 100,
 };
···
 {
 	palmz72_cam_gpio_init();
 	pxa_set_camera_info(&palmz72_pxacamera_platform_data);
+	gpiod_add_lookup_table(&palmz72_i2c_gpiod_table);
 	platform_device_register(&palmz72_i2c_bus_device);
 	platform_device_register(&palmz72_camera);
 }

arch/arm/mach-pxa/viper.c

···
 #include <linux/gpio.h>
 #include <linux/jiffies.h>
 #include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/i2c/pxa-i2c.h>
 #include <linux/serial_8250.h>
 #include <linux/smc91x.h>
···
 };
 
 /* i2c */
+static struct gpiod_lookup_table viper_i2c_gpiod_table = {
+	.dev_id		= "i2c-gpio",
+	.table		= {
+		GPIO_LOOKUP_IDX("gpio-pxa", VIPER_RTC_I2C_SDA_GPIO,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("gpio-pxa", VIPER_RTC_I2C_SCL_GPIO,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data i2c_bus_data = {
-	.sda_pin = VIPER_RTC_I2C_SDA_GPIO,
-	.scl_pin = VIPER_RTC_I2C_SCL_GPIO,
 	.udelay  = 10,
 	.timeout = HZ,
 };
···
 
 __setup("tpm=", viper_tpm_setup);
 
+struct gpiod_lookup_table viper_tpm_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("gpio-pxa", VIPER_TPM_I2C_SDA_GPIO,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("gpio-pxa", VIPER_TPM_I2C_SCL_GPIO,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
+};
+
 static void __init viper_tpm_init(void)
 {
 	struct platform_device *tpm_device;
 	struct i2c_gpio_platform_data i2c_tpm_data = {
-		.sda_pin = VIPER_TPM_I2C_SDA_GPIO,
-		.scl_pin = VIPER_TPM_I2C_SCL_GPIO,
 		.udelay  = 10,
 		.timeout = HZ,
 	};
···
 	if (!viper_tpm)
 		return;
 
+	gpiod_add_lookup_table(&viper_tpm_i2c_gpiod_table);
 	tpm_device = platform_device_alloc("i2c-gpio", 2);
 	if (tpm_device) {
 		if (!platform_device_add_data(tpm_device,
···
 		smc91x_device.num_resources--;
 
 	pxa_set_i2c_info(NULL);
+	gpiod_add_lookup_table(&viper_i2c_gpiod_table);
 	pwm_add_table(viper_pwm_lookup, ARRAY_SIZE(viper_pwm_lookup));
 	platform_add_devices(viper_devs, ARRAY_SIZE(viper_devs));
 

arch/arm/mach-sa1100/simpad.c

···
 #include <linux/mtd/partitions.h>
 #include <linux/io.h>
 #include <linux/gpio/driver.h>
+#include <linux/gpio/machine.h>
 
 #include <mach/hardware.h>
 #include <asm/setup.h>
···
 /*
  * i2c
  */
+static struct gpiod_lookup_table simpad_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("gpio", GPIO_GPIO21, NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("gpio", GPIO_GPIO25, NULL, 1, GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data simpad_i2c_data = {
-	.sda_pin = GPIO_GPIO21,
-	.scl_pin = GPIO_GPIO25,
 	.udelay = 10,
 	.timeout = HZ,
 };
···
 			      ARRAY_SIZE(simpad_flash_resources));
 	sa11x0_register_mcp(&simpad_mcp_data);
 
+	gpiod_add_lookup_table(&simpad_i2c_gpiod_table);
 	ret = platform_add_devices(devices, ARRAY_SIZE(devices));
 	if(ret)
 		printk(KERN_WARNING "simpad: Unable to register mq200 framebuffer device");

arch/blackfin/mach-bf533/boards/blackstamp.c

···
 #include <linux/irq.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>
+#include <linux/gpio/machine.h>
 #include <asm/dma.h>
 #include <asm/bfin5xx_spi.h>
 #include <asm/portmux.h>
···
 #if IS_ENABLED(CONFIG_I2C_GPIO)
 #include <linux/i2c-gpio.h>
 
+static struct gpiod_lookup_table bfin_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF8, NULL, 0,
+				GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF9, NULL, 1,
+				GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data i2c_gpio_data = {
-	.sda_pin		= GPIO_PF8,
-	.scl_pin		= GPIO_PF9,
-	.sda_is_open_drain	= 0,
-	.scl_is_open_drain	= 0,
 	.udelay			= 40,
 }; /* This hasn't actually been used these pins
     * are (currently) free pins on the expansion connector */
···
 	int ret;
 
 	printk(KERN_INFO "%s(): registering device resources\n", __func__);
-
+#if IS_ENABLED(CONFIG_I2C_GPIO)
+	gpiod_add_lookup_table(&bfin_i2c_gpiod_table);
+#endif
 	i2c_register_board_info(0, bfin_i2c_board_info,
 				ARRAY_SIZE(bfin_i2c_board_info));
 

arch/blackfin/mach-bf533/boards/ezkit.c

···
 #endif
 #include <linux/irq.h>
 #include <linux/i2c.h>
+#include <linux/gpio/machine.h>
 #include <asm/dma.h>
 #include <asm/bfin5xx_spi.h>
 #include <asm/portmux.h>
···
 #if IS_ENABLED(CONFIG_I2C_GPIO)
 #include <linux/i2c-gpio.h>
 
+static struct gpiod_lookup_table bfin_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF1, NULL, 0,
+				GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF0, NULL, 1,
+				GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data i2c_gpio_data = {
-	.sda_pin		= GPIO_PF1,
-	.scl_pin		= GPIO_PF0,
-	.sda_is_open_drain	= 0,
-	.scl_is_open_drain	= 0,
 	.udelay			= 40,
 };
 
···
 static int __init ezkit_init(void)
 {
 	printk(KERN_INFO "%s(): registering device resources\n", __func__);
+#if IS_ENABLED(CONFIG_I2C_GPIO)
+	gpiod_add_lookup_table(&bfin_i2c_gpiod_table);
+#endif
 	platform_add_devices(ezkit_devices, ARRAY_SIZE(ezkit_devices));
 	spi_register_board_info(bfin_spi_board_info, ARRAY_SIZE(bfin_spi_board_info));
 	i2c_register_board_info(0, bfin_i2c_board_info,

arch/blackfin/mach-bf533/boards/stamp.c

···
 #include <linux/gpio.h>
 #include <linux/irq.h>
 #include <linux/i2c.h>
+#include <linux/gpio/machine.h>
 #include <asm/dma.h>
 #include <asm/bfin5xx_spi.h>
 #include <asm/reboot.h>
···
 #if IS_ENABLED(CONFIG_I2C_GPIO)
 #include <linux/i2c-gpio.h>
 
+static struct gpiod_lookup_table bfin_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF2, NULL, 0,
+				GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF3, NULL, 1,
+				GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data i2c_gpio_data = {
-	.sda_pin		= GPIO_PF2,
-	.scl_pin		= GPIO_PF3,
-	.sda_is_open_drain	= 0,
-	.scl_is_open_drain	= 0,
 	.udelay			= 10,
 };
 
···
 
 	printk(KERN_INFO "%s(): registering device resources\n", __func__);
 
+#if IS_ENABLED(CONFIG_I2C_GPIO)
+	gpiod_add_lookup_table(&bfin_i2c_gpiod_table);
+#endif
 	i2c_register_board_info(0, bfin_i2c_board_info,
 				ARRAY_SIZE(bfin_i2c_board_info));
 

arch/blackfin/mach-bf561/boards/ezkit.c

···
 #include <linux/interrupt.h>
 #include <linux/gpio.h>
 #include <linux/delay.h>
+#include <linux/gpio/machine.h>
 #include <asm/dma.h>
 #include <asm/bfin5xx_spi.h>
 #include <asm/portmux.h>
···
 #if IS_ENABLED(CONFIG_I2C_GPIO)
 #include <linux/i2c-gpio.h>
 
+static struct gpiod_lookup_table bfin_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF1, NULL, 0,
+				GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("BFIN-GPIO", GPIO_PF0, NULL, 1,
+				GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data i2c_gpio_data = {
-	.sda_pin		= GPIO_PF1,
-	.scl_pin		= GPIO_PF0,
-	.sda_is_open_drain	= 0,
-	.scl_is_open_drain	= 0,
 	.udelay			= 10,
 };
 
···
 
 	printk(KERN_INFO "%s(): registering device resources\n", __func__);
 
+#if IS_ENABLED(CONFIG_I2C_GPIO)
+	gpiod_add_lookup_table(&bfin_i2c_gpiod_table);
+#endif
 	ret = platform_add_devices(ezkit_devices, ARRAY_SIZE(ezkit_devices));
 	if (ret < 0)
 		return ret;

arch/mips/alchemy/board-gpr.c

···
 #include <linux/gpio.h>
 #include <linux/i2c.h>
 #include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <asm/bootinfo.h>
 #include <asm/idle.h>
 #include <asm/reboot.h>
···
 /*
  * I2C
  */
+static struct gpiod_lookup_table gpr_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		/*
+		 * This should be on "GPIO2" which has base at 200 so
+		 * the global numbers 209 and 210 should correspond to
+		 * local offsets 9 and 10.
+		 */
+		GPIO_LOOKUP_IDX("alchemy-gpio2", 9, NULL, 0,
+				GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("alchemy-gpio2", 10, NULL, 1,
+				GPIO_ACTIVE_HIGH),
+	},
+};
+
 static struct i2c_gpio_platform_data gpr_i2c_data = {
-	.sda_pin		= 209,
 	.sda_is_open_drain	= 1,
-	.scl_pin		= 210,
 	.scl_is_open_drain	= 1,
 	.udelay			= 2,		/* ~100 kHz */
 	.timeout		= HZ,
···
 
 static int __init gpr_dev_init(void)
 {
+	gpiod_add_lookup_table(&gpr_i2c_gpiod_table);
 	i2c_register_board_info(0, gpr_i2c_info, ARRAY_SIZE(gpr_i2c_info));
 
 	return platform_add_devices(gpr_devices, ARRAY_SIZE(gpr_devices));

arch/mips/ath79/mach-pb44.c

···
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>
-#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/platform_data/pcf857x.h>
 
 #include "machtypes.h"
···
 #define PB44_KEYS_POLL_INTERVAL		20	/* msecs */
 #define PB44_KEYS_DEBOUNCE_INTERVAL	(3 * PB44_KEYS_POLL_INTERVAL)
 
-static struct i2c_gpio_platform_data pb44_i2c_gpio_data = {
-	.sda_pin	= PB44_GPIO_I2C_SDA,
-	.scl_pin	= PB44_GPIO_I2C_SCL,
+static struct gpiod_lookup_table pb44_i2c_gpiod_table = {
+	.dev_id = "i2c-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("ath79-gpio", PB44_GPIO_I2C_SDA,
+				NULL, 0, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("ath79-gpio", PB44_GPIO_I2C_SCL,
+				NULL, 1, GPIO_ACTIVE_HIGH),
+	},
 };
 
 static struct platform_device pb44_i2c_gpio_device = {
 	.name		= "i2c-gpio",
 	.id		= 0,
 	.dev = {
-		.platform_data	= &pb44_i2c_gpio_data,
+		.platform_data	= NULL,
 	}
 };
 
···
 
 static void __init pb44_init(void)
 {
+	gpiod_add_lookup_table(&pb44_i2c_gpiod_table);
 	i2c_register_board_info(0, pb44_i2c_board_info,
 				ARRAY_SIZE(pb44_i2c_board_info));
 	platform_device_register(&pb44_i2c_gpio_device);

drivers/i2c/busses/i2c-gpio.c

···
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 
 struct i2c_gpio_private_data {
+	struct gpio_desc *sda;
+	struct gpio_desc *scl;
 	struct i2c_adapter adap;
 	struct i2c_algo_bit_data bit_data;
 	struct i2c_gpio_platform_data pdata;
···
 /* Toggle SDA by changing the direction of the pin */
 static void i2c_gpio_setsda_dir(void *data, int state)
 {
-	struct i2c_gpio_platform_data *pdata = data;
+	struct i2c_gpio_private_data *priv = data;
 
+	/*
+	 * This is a way of saying "do not drive
+	 * me actively high" which means emulating open drain.
+	 * The right way to do this is for gpiolib to
+	 * handle this, by the function below.
+	 */
 	if (state)
-		gpio_direction_input(pdata->sda_pin);
+		gpiod_direction_input(priv->sda);
 	else
-		gpio_direction_output(pdata->sda_pin, 0);
+		gpiod_direction_output(priv->sda, 0);
 }
 
 /*
···
  */
 static void i2c_gpio_setsda_val(void *data, int state)
 {
-	struct i2c_gpio_platform_data *pdata = data;
+	struct i2c_gpio_private_data *priv = data;
 
-	gpio_set_value(pdata->sda_pin, state);
+	gpiod_set_value(priv->sda, state);
 }
 
 /* Toggle SCL by changing the direction of the pin. */
 static void i2c_gpio_setscl_dir(void *data, int state)
 {
-	struct i2c_gpio_platform_data *pdata = data;
+	struct i2c_gpio_private_data *priv = data;
 
 	if (state)
-		gpio_direction_input(pdata->scl_pin);
+		gpiod_direction_input(priv->scl);
 	else
-		gpio_direction_output(pdata->scl_pin, 0);
+		gpiod_direction_output(priv->scl, 0);
 }
 
 /*
···
  */
 static void i2c_gpio_setscl_val(void *data, int state)
 {
-	struct i2c_gpio_platform_data *pdata = data;
+	struct i2c_gpio_private_data *priv = data;
 
-	gpio_set_value(pdata->scl_pin, state);
+	gpiod_set_value(priv->scl, state);
 }
 
 static int i2c_gpio_getsda(void *data)
 {
-	struct i2c_gpio_platform_data *pdata = data;
+	struct i2c_gpio_private_data *priv = data;
 
-	return gpio_get_value(pdata->sda_pin);
+	return gpiod_get_value(priv->sda);
 }
 
 static int i2c_gpio_getscl(void *data)
 {
-	struct i2c_gpio_platform_data *pdata = data;
+	struct i2c_gpio_private_data *priv = data;
 
-	return gpio_get_value(pdata->scl_pin);
-}
-
-static int of_i2c_gpio_get_pins(struct device_node *np,
-				unsigned int *sda_pin, unsigned int *scl_pin)
-{
-	if (of_gpio_count(np) < 2)
-		return -ENODEV;
-
-	*sda_pin = of_get_gpio(np, 0);
-	*scl_pin = of_get_gpio(np, 1);
-
-	if (*sda_pin == -EPROBE_DEFER || *scl_pin == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
-
-	if (!gpio_is_valid(*sda_pin) || !gpio_is_valid(*scl_pin)) {
-		pr_err("%pOF: invalid GPIO pins, sda=%d/scl=%d\n",
-		       np, *sda_pin, *scl_pin);
-		return -ENODEV;
-	}
-
-	return 0;
+	return gpiod_get_value(priv->scl);
 }
 
 static void of_i2c_gpio_get_props(struct device_node *np,
···
 	struct i2c_gpio_platform_data *pdata;
 	struct i2c_algo_bit_data *bit_data;
 	struct i2c_adapter *adap;
-	unsigned int sda_pin, scl_pin;
 	int ret;
-
-	/* First get the GPIO pins; if it fails, we'll defer the probe. */
-	if (pdev->dev.of_node) {
-		ret = of_i2c_gpio_get_pins(pdev->dev.of_node,
-					   &sda_pin, &scl_pin);
-		if (ret)
-			return ret;
-	} else {
-		if (!dev_get_platdata(&pdev->dev))
-			return -ENXIO;
-		pdata = dev_get_platdata(&pdev->dev);
-		sda_pin = pdata->sda_pin;
-		scl_pin = pdata->scl_pin;
-	}
-
-	ret = devm_gpio_request(&pdev->dev, sda_pin, "sda");
-	if (ret) {
-		if (ret == -EINVAL)
-			ret = -EPROBE_DEFER;	/* Try again later */
-		return ret;
-	}
-	ret = devm_gpio_request(&pdev->dev, scl_pin, "scl");
-	if (ret) {
-		if (ret == -EINVAL)
-			ret = -EPROBE_DEFER;	/* Try again later */
-		return ret;
-	}
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
+
+	/* First get the GPIO pins; if it fails, we'll defer the probe. */
+	priv->sda = devm_gpiod_get_index(&pdev->dev, NULL, 0, GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->sda)) {
+		ret = PTR_ERR(priv->sda);
+		/* FIXME: hack in the old code, is this really necessary? */
+		if (ret == -EINVAL)
+			ret = -EPROBE_DEFER;
+		return ret;
+	}
+	priv->scl = devm_gpiod_get_index(&pdev->dev, NULL, 1, GPIOD_OUT_LOW);
+	if (IS_ERR(priv->scl)) {
+		ret = PTR_ERR(priv->scl);
+		/* FIXME: hack in the old code, is this really necessary? */
+		if (ret == -EINVAL)
+			ret = -EPROBE_DEFER;
+		return ret;
+	}
+
 	adap = &priv->adap;
 	bit_data = &priv->bit_data;
 	pdata = &priv->pdata;
 
 	if (pdev->dev.of_node) {
-		pdata->sda_pin = sda_pin;
-		pdata->scl_pin = scl_pin;
 		of_i2c_gpio_get_props(pdev->dev.of_node, pdata);
 	} else {
-		memcpy(pdata, dev_get_platdata(&pdev->dev), sizeof(*pdata));
+		/*
+		 * If all platform data settings are zero it is OK
+		 * to not provide any platform data from the board.
+		 */
+		if (dev_get_platdata(&pdev->dev))
+			memcpy(pdata, dev_get_platdata(&pdev->dev),
+			       sizeof(*pdata));
 	}
 
+	/*
+	 * FIXME: this is a hack emulating the open drain emulation
+	 * that gpiolib can already do for us. Make all clients properly
+	 * flag their lines as open drain and get rid of this property
+	 * and the special callback.
+	 */
 	if (pdata->sda_is_open_drain) {
-		gpio_direction_output(pdata->sda_pin, 1);
+		gpiod_direction_output(priv->sda, 1);
 		bit_data->setsda = i2c_gpio_setsda_val;
 	} else {
-		gpio_direction_input(pdata->sda_pin);
+		gpiod_direction_input(priv->sda);
 		bit_data->setsda = i2c_gpio_setsda_dir;
 	}
 
 	if (pdata->scl_is_open_drain || pdata->scl_is_output_only) {
-		gpio_direction_output(pdata->scl_pin, 1);
+		gpiod_direction_output(priv->scl, 1);
 		bit_data->setscl = i2c_gpio_setscl_val;
 	} else {
-		gpio_direction_input(pdata->scl_pin);
+		gpiod_direction_input(priv->scl);
 		bit_data->setscl = i2c_gpio_setscl_dir;
 	}
 
···
 	else
 		bit_data->timeout = HZ / 10;		/* 100 ms */
 
-	bit_data->data = pdata;
+	bit_data->data = priv;
 
 	adap->owner = THIS_MODULE;
 	if (pdev->dev.of_node)
···
 
 	platform_set_drvdata(pdev, priv);
 
-	dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n",
-		 pdata->sda_pin, pdata->scl_pin,
+	/*
+	 * FIXME: using global GPIO numbers is not helpful. If/when we
+	 * get accessors to get the actual name of the GPIO line,
+	 * from the descriptor, then provide that instead.
+	 */
+	dev_info(&pdev->dev, "using lines %u (SDA) and %u (SCL%s)\n",
+		 desc_to_gpio(priv->sda), desc_to_gpio(priv->scl),
 		 pdata->scl_is_output_only
 		 ? ", no clock stretching" : "");
 

drivers/mfd/sm501.c

···
 #include <linux/platform_device.h>
 #include <linux/pci.h>
 #include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/slab.h>
 
 #include <linux/sm501.h>
···
 	kfree(gpio->regs_res);
 }
 
-static inline int sm501_gpio_pin2nr(struct sm501_devdata *sm, unsigned int pin)
-{
-	struct sm501_gpio *gpio = &sm->gpio;
-	int base = (pin < 32) ? gpio->low.gpio.base : gpio->high.gpio.base;
-
-	return (pin % 32) + base;
-}
-
 static inline int sm501_gpio_isregistered(struct sm501_devdata *sm)
 {
 	return sm->gpio.registered;
···
 {
 }
 
-static inline int sm501_gpio_pin2nr(struct sm501_devdata *sm, unsigned int pin)
-{
-	return -1;
-}
-
 static inline int sm501_gpio_isregistered(struct sm501_devdata *sm)
 {
 	return 0;
···
 {
 	struct i2c_gpio_platform_data *icd;
 	struct platform_device *pdev;
+	struct gpiod_lookup_table *lookup;
 
 	pdev = sm501_create_subdev(sm, "i2c-gpio", 0,
 				   sizeof(struct i2c_gpio_platform_data));
 	if (!pdev)
 		return -ENOMEM;
 
+	/* Create a gpiod lookup using gpiochip-local offsets */
+	lookup = devm_kzalloc(&pdev->dev,
+			      sizeof(*lookup) + 3 * sizeof(struct gpiod_lookup),
+			      GFP_KERNEL);
+	lookup->dev_id = "i2c-gpio";
+	if (iic->pin_sda < 32)
+		lookup->table[0].chip_label = "SM501-LOW";
+	else
+		lookup->table[0].chip_label = "SM501-HIGH";
+	lookup->table[0].chip_hwnum = iic->pin_sda % 32;
+	lookup->table[0].con_id = NULL;
+	lookup->table[0].idx = 0;
+	lookup->table[0].flags = GPIO_ACTIVE_HIGH;
+	if (iic->pin_scl < 32)
+		lookup->table[1].chip_label = "SM501-LOW";
+	else
+		lookup->table[1].chip_label = "SM501-HIGH";
+	lookup->table[1].chip_hwnum = iic->pin_scl % 32;
+	lookup->table[1].con_id = NULL;
+	lookup->table[1].idx = 1;
+	lookup->table[1].flags = GPIO_ACTIVE_HIGH;
+	gpiod_add_lookup_table(lookup);
+
 	icd = dev_get_platdata(&pdev->dev);
-
-	/* We keep the pin_sda and pin_scl fields relative in case the
-	 * same platform data is passed to >1 SM501.
-	 */
-
-	icd->sda_pin = sm501_gpio_pin2nr(sm, iic->pin_sda);
-	icd->scl_pin = sm501_gpio_pin2nr(sm, iic->pin_scl);
 	icd->timeout = iic->timeout;
 	icd->udelay = iic->udelay;
 
···
 
 	pdev->id = iic->bus_num;
 
-	dev_info(sm->dev, "registering i2c-%d: sda=%d (%d), scl=%d (%d)\n",
+	dev_info(sm->dev, "registering i2c-%d: sda=%d, scl=%d\n",
 		 iic->bus_num,
-		 icd->sda_pin, iic->pin_sda, icd->scl_pin, iic->pin_scl);
+		 iic->pin_sda, iic->pin_scl);
 
 	return sm501_register_device(sm, pdev);
 }

include/linux/i2c-gpio.h

···
 
 /**
  * struct i2c_gpio_platform_data - Platform-dependent data for i2c-gpio
- * @sda_pin: GPIO pin ID to use for SDA
- * @scl_pin: GPIO pin ID to use for SCL
  * @udelay: signal toggle delay. SCL frequency is (500 / udelay) kHz
  * @timeout: clock stretching timeout in jiffies. If the slave keeps
  *	SCL low for longer than this, the transfer will time out.
···
  * @scl_is_output_only: SCL output drivers cannot be turned off.
  */
 struct i2c_gpio_platform_data {
-	unsigned int	sda_pin;
-	unsigned int	scl_pin;
 	int		udelay;
 	int		timeout;
 	unsigned int	sda_is_open_drain:1;