1 files changed, 245 insertions, 348 deletions

diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c
index a54524cf42cc..c8dadb532c40 100644
--- a/drivers/spi/spi-gpio.c
+++ b/drivers/spi/spi-gpio.c
@@ -1,37 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
- * SPI master driver using generic bitbanged GPIO
+ * SPI host driver using generic bitbanged GPIO
  *
  * Copyright (C) 2006,2008 David Brownell
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * Copyright (C) 2017 Linus Walleij
  */
+#include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/platform_device.h>
-#include <linux/gpio.h>
-#include <linux/of_device.h>
-#include <linux/of_gpio.h>
+#include <linux/property.h>
 
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
 #include <linux/spi/spi_gpio.h>
 
-
 /*
- * This bitbanging SPI master driver should help make systems usable
+ * This bitbanging SPI host driver should help make systems usable
  * when a native hardware SPI engine is not available, perhaps because
  * its driver isn't yet working or because the I/O pins it requires
  * are used for other purposes.
@@ -39,95 +25,59 @@
  * platform_device->driver_data ... points to spi_gpio
  *
  * spi->controller_state ... reserved for bitbang framework code
- * spi->controller_data ... holds chipselect GPIO
  *
- * spi->master->dev.driver_data ... points to spi_gpio->bitbang
+ * spi->controller->dev.driver_data ... points to spi_gpio->bitbang
  */
 
 struct spi_gpio {
 	struct spi_bitbang		bitbang;
-	struct spi_gpio_platform_data	pdata;
-	struct platform_device		*pdev;
-	int				cs_gpios[0];
+	struct gpio_desc		*sck;
+	struct gpio_desc		*miso;
+	struct gpio_desc		*mosi;
+	struct gpio_desc		**cs_gpios;
 };
 
 /*----------------------------------------------------------------------*/
 
-/*
- * Because the overhead of going through four GPIO procedure calls
- * per transferred bit can make performance a problem, this code
- * is set up so that you can use it in either of two ways:
- *
- *   - The slow generic way:  set up platform_data to hold the GPIO
- *     numbers used for MISO/MOSI/SCK, and issue procedure calls for
- *     each of them.  This driver can handle several such busses.
- *
- *   - The quicker inlined way:  only helps with platform GPIO code
- *     that inlines operations for constant GPIOs.  This can give
- *     you tight (fast!) inner loops, but each such bus needs a
- *     new driver.  You'll define a new C file, with Makefile and
- *     Kconfig support; the C code can be a total of six lines:
- *
- *		#define DRIVER_NAME	"myboard_spi2"
- *		#define	SPI_MISO_GPIO	119
- *		#define	SPI_MOSI_GPIO	120
- *		#define	SPI_SCK_GPIO	121
- *		#define	SPI_N_CHIPSEL	4
- *		#include "spi-gpio.c"
- */
-
-#ifndef DRIVER_NAME
 #define DRIVER_NAME	"spi_gpio"
 
-#define GENERIC_BITBANG	/* vs tight inlines */
-
-/* all functions referencing these symbols must define pdata */
-#define SPI_MISO_GPIO	((pdata)->miso)
-#define SPI_MOSI_GPIO	((pdata)->mosi)
-#define SPI_SCK_GPIO	((pdata)->sck)
-
-#define SPI_N_CHIPSEL	((pdata)->num_chipselect)
-
-#endif
-
 /*----------------------------------------------------------------------*/
 
-static inline struct spi_gpio * __pure
+static inline struct spi_gpio *__pure
 spi_to_spi_gpio(const struct spi_device *spi)
 {
-	const struct spi_bitbang	*bang;
+	struct spi_bitbang		*bang;
 	struct spi_gpio			*spi_gpio;
 
-	bang = spi_master_get_devdata(spi->master);
+	bang = spi_controller_get_devdata(spi->controller);
 	spi_gpio = container_of(bang, struct spi_gpio, bitbang);
 	return spi_gpio;
 }
 
-static inline struct spi_gpio_platform_data * __pure
-spi_to_pdata(const struct spi_device *spi)
-{
-	return &spi_to_spi_gpio(spi)->pdata;
-}
-
-/* this is #defined to avoid unused-variable warnings when inlining */
-#define pdata		spi_to_pdata(spi)
-
+/* These helpers are in turn called by the bitbang inlines */
 static inline void setsck(const struct spi_device *spi, int is_on)
 {
-	gpio_set_value(SPI_SCK_GPIO, is_on);
+	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
+
+	gpiod_set_value_cansleep(spi_gpio->sck, is_on);
 }
 
 static inline void setmosi(const struct spi_device *spi, int is_on)
 {
-	gpio_set_value(SPI_MOSI_GPIO, is_on);
+	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
+
+	gpiod_set_value_cansleep(spi_gpio->mosi, is_on);
 }
 
 static inline int getmiso(const struct spi_device *spi)
 {
-	return !!gpio_get_value(SPI_MISO_GPIO);
-}
+	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
 
-#undef pdata
+	if (spi->mode & SPI_3WIRE)
+		return !!gpiod_get_value_cansleep(spi_gpio->mosi);
+	else
+		return !!gpiod_get_value_cansleep(spi_gpio->miso);
+}
 
 /*
  * NOTE:  this clocks "as fast as we can".  It "should" be a function of the
@@ -154,32 +104,44 @@ static inline int getmiso(const struct spi_device *spi)
  */
 
 static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha0(spi, nsecs, 0, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits);
 }
 
 static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha1(spi, nsecs, 0, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits);
 }
 
 static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha0(spi, nsecs, 1, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits);
 }
 
 static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha1(spi, nsecs, 1, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits);
 }
 
 /*
  * These functions do not call setmosi or getmiso if respective flag
- * (SPI_MASTER_NO_RX or SPI_MASTER_NO_TX) is set, so they are safe to
+ * (SPI_CONTROLLER_NO_RX or SPI_CONTROLLER_NO_TX) is set, so they are safe to
  * call when such pin is not present or defined in the controller.
  * A separate set of callbacks is defined to get highest possible
  * speed in the generic case (when both MISO and MOSI lines are
@@ -188,31 +150,43 @@ static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi,
  */
 
 static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	unsigned flags = spi->master->flags;
-	return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits);
+	flags = spi->controller->flags;
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha0(spi, nsecs, 0, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits);
 }
 
 static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	unsigned flags = spi->master->flags;
-	return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits);
+	flags = spi->controller->flags;
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha1(spi, nsecs, 0, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits);
 }
 
 static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	unsigned flags = spi->master->flags;
-	return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits);
+	flags = spi->controller->flags;
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha0(spi, nsecs, 1, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits);
 }
 
 static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi,
-		unsigned nsecs, u32 word, u8 bits)
+		unsigned int nsecs, u32 word, u8 bits, unsigned int flags)
 {
-	unsigned flags = spi->master->flags;
-	return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits);
+	flags = spi->controller->flags;
+	if (unlikely(spi->mode & SPI_LSB_FIRST))
+		return bitbang_txrx_le_cpha1(spi, nsecs, 1, flags, word, bits);
+	else
+		return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits);
 }
 
 /*----------------------------------------------------------------------*/
@@ -220,320 +194,243 @@ static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi,
 static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
 {
 	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
-	unsigned int cs = spi_gpio->cs_gpios[spi->chip_select];
 
-	/* set initial clock polarity */
+	/* set initial clock line level */
 	if (is_active)
-		setsck(spi, spi->mode & SPI_CPOL);
+		gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL);
 
-	if (cs != SPI_GPIO_NO_CHIPSELECT) {
-		/* SPI is normally active-low */
-		gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
+	/* Drive chip select line, if we have one */
+	if (spi_gpio->cs_gpios) {
+		struct gpio_desc *cs = spi_gpio->cs_gpios[spi_get_chipselect(spi, 0)];
+
+		/* SPI chip selects are normally active-low */
+		gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
 	}
 }
 
+static void spi_gpio_set_mosi_idle(struct spi_device *spi)
+{
+	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
+
+	gpiod_set_value_cansleep(spi_gpio->mosi,
+				 !!(spi->mode & SPI_MOSI_IDLE_HIGH));
+}
+
 static int spi_gpio_setup(struct spi_device *spi)
 {
-	unsigned int		cs;
-	int			status = 0;
+	struct gpio_desc	*cs;
 	struct spi_gpio		*spi_gpio = spi_to_spi_gpio(spi);
-	struct device_node	*np = spi->master->dev.of_node;
-
-	if (np) {
-		/*
-		 * In DT environments, the CS GPIOs have already been
-		 * initialized from the "cs-gpios" property of the node.
-		 */
-		cs = spi_gpio->cs_gpios[spi->chip_select];
-	} else {
-		/*
-		 * ... otherwise, take it from spi->controller_data
-		 */
-		cs = (unsigned int) spi->controller_data;
-	}
+	int ret;
 
-	if (!spi->controller_state) {
-		if (cs != SPI_GPIO_NO_CHIPSELECT) {
-			status = gpio_request(cs, dev_name(&spi->dev));
-			if (status)
-				return status;
-			status = gpio_direction_output(cs,
-					!(spi->mode & SPI_CS_HIGH));
+	/*
+	 * The CS GPIOs have already been
+	 * initialized from the descriptor lookup.
+	 */
+	if (spi_gpio->cs_gpios) {
+		cs = spi_gpio->cs_gpios[spi_get_chipselect(spi, 0)];
+		if (!spi->controller_state && cs) {
+			ret = gpiod_direction_output(cs, !(spi->mode & SPI_CS_HIGH));
+			if (ret)
+				return ret;
 		}
 	}
-	if (!status) {
-		/* in case it was initialized from static board data */
-		spi_gpio->cs_gpios[spi->chip_select] = cs;
-		status = spi_bitbang_setup(spi);
-	}
 
-	if (status) {
-		if (!spi->controller_state && cs != SPI_GPIO_NO_CHIPSELECT)
-			gpio_free(cs);
-	}
-	return status;
+	return spi_bitbang_setup(spi);
 }
 
-static void spi_gpio_cleanup(struct spi_device *spi)
+static int spi_gpio_set_direction(struct spi_device *spi, bool output)
 {
 	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
-	unsigned int cs = spi_gpio->cs_gpios[spi->chip_select];
+	int ret;
 
-	if (cs != SPI_GPIO_NO_CHIPSELECT)
-		gpio_free(cs);
-	spi_bitbang_cleanup(spi);
+	if (output)
+		return gpiod_direction_output(spi_gpio->mosi, 1);
+
+	/*
+	 * Only change MOSI to an input if using 3WIRE mode.
+	 * Otherwise, MOSI could be left floating if there is
+	 * no pull resistor connected to the I/O pin, or could
+	 * be left logic high if there is a pull-up. Transmitting
+	 * logic high when only clocking MISO data in can put some
+	 * SPI devices in to a bad state.
+	 */
+	if (spi->mode & SPI_3WIRE) {
+		ret = gpiod_direction_input(spi_gpio->mosi);
+		if (ret)
+			return ret;
+	}
+	/*
+	 * Send a turnaround high impedance cycle when switching
+	 * from output to input. Theoretically there should be
+	 * a clock delay here, but as has been noted above, the
+	 * nsec delay function for bit-banged GPIO is simply
+	 * {} because bit-banging just doesn't get fast enough
+	 * anyway.
+	 */
+	if (spi->mode & SPI_3WIRE_HIZ) {
+		gpiod_set_value_cansleep(spi_gpio->sck,
+					 !(spi->mode & SPI_CPOL));
+		gpiod_set_value_cansleep(spi_gpio->sck,
+					 !!(spi->mode & SPI_CPOL));
+	}
+	return 0;
 }
 
-static int spi_gpio_alloc(unsigned pin, const char *label, bool is_in)
+static void spi_gpio_cleanup(struct spi_device *spi)
 {
-	int value;
-
-	value = gpio_request(pin, label);
-	if (value == 0) {
-		if (is_in)
-			value = gpio_direction_input(pin);
-		else
-			value = gpio_direction_output(pin, 0);
-	}
-	return value;
+	spi_bitbang_cleanup(spi);
 }
 
-static int spi_gpio_request(struct spi_gpio_platform_data *pdata,
-			    const char *label, u16 *res_flags)
+/*
+ * It can be convenient to use this driver with pins that have alternate
+ * functions associated with a "native" SPI controller if a driver for that
+ * controller is not available, or is missing important functionality.
+ *
+ * On platforms which can do so, configure MISO with a weak pullup unless
+ * there's an external pullup on that signal.  That saves power by avoiding
+ * floating signals.  (A weak pulldown would save power too, but many
+ * drivers expect to see all-ones data as the no target "response".)
+ */
+static int spi_gpio_request(struct device *dev, struct spi_gpio *spi_gpio)
 {
-	int value;
-
-	/* NOTE:  SPI_*_GPIO symbols may reference "pdata" */
+	spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW);
+	if (IS_ERR(spi_gpio->mosi))
+		return PTR_ERR(spi_gpio->mosi);
 
-	if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) {
-		value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false);
-		if (value)
-			goto done;
-	} else {
-		/* HW configuration without MOSI pin */
-		*res_flags |= SPI_MASTER_NO_TX;
-	}
-
-	if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) {
-		value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
-		if (value)
-			goto free_mosi;
-	} else {
-		/* HW configuration without MISO pin */
-		*res_flags |= SPI_MASTER_NO_RX;
-	}
+	spi_gpio->miso = devm_gpiod_get_optional(dev, "miso", GPIOD_IN);
+	if (IS_ERR(spi_gpio->miso))
+		return PTR_ERR(spi_gpio->miso);
 
-	value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
-	if (value)
-		goto free_miso;
-
-	goto done;
-
-free_miso:
-	if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
-		gpio_free(SPI_MISO_GPIO);
-free_mosi:
-	if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
-		gpio_free(SPI_MOSI_GPIO);
-done:
-	return value;
+	spi_gpio->sck = devm_gpiod_get(dev, "sck", GPIOD_OUT_LOW);
+	return PTR_ERR_OR_ZERO(spi_gpio->sck);
 }
 
-#ifdef CONFIG_OF
-static struct of_device_id spi_gpio_dt_ids[] = {
-	{ .compatible = "spi-gpio" },
-	{}
-};
-MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids);
-
-static int spi_gpio_probe_dt(struct platform_device *pdev)
+static int spi_gpio_probe_pdata(struct platform_device *pdev,
+				struct spi_controller *host)
 {
-	int ret;
-	u32 tmp;
-	struct spi_gpio_platform_data	*pdata;
-	struct device_node *np = pdev->dev.of_node;
-	const struct of_device_id *of_id =
-			of_match_device(spi_gpio_dt_ids, &pdev->dev);
+	struct device *dev = &pdev->dev;
+	struct spi_gpio_platform_data *pdata = dev_get_platdata(dev);
+	struct spi_gpio *spi_gpio = spi_controller_get_devdata(host);
+	int i;
+
+	if (!pdata)
+		return -ENODEV;
 
-	if (!of_id)
+	/* It's just one always-selected device, fine to continue */
+	if (!pdata->num_chipselect)
 		return 0;
 
-	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
-	if (!pdata)
+	host->num_chipselect = pdata->num_chipselect;
+	spi_gpio->cs_gpios = devm_kcalloc(dev, host->num_chipselect,
+					  sizeof(*spi_gpio->cs_gpios),
+					  GFP_KERNEL);
+	if (!spi_gpio->cs_gpios)
 		return -ENOMEM;
 
-	ret = of_get_named_gpio(np, "gpio-sck", 0);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "gpio-sck property not found\n");
-		goto error_free;
+	for (i = 0; i < host->num_chipselect; i++) {
+		spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", i,
+							     GPIOD_OUT_HIGH);
+		if (IS_ERR(spi_gpio->cs_gpios[i]))
+			return PTR_ERR(spi_gpio->cs_gpios[i]);
 	}
-	pdata->sck = ret;
-
-	ret = of_get_named_gpio(np, "gpio-miso", 0);
-	if (ret < 0) {
-		dev_info(&pdev->dev, "gpio-miso property not found, switching to no-rx mode\n");
-		pdata->miso = SPI_GPIO_NO_MISO;
-	} else
-		pdata->miso = ret;
-
-	ret = of_get_named_gpio(np, "gpio-mosi", 0);
-	if (ret < 0) {
-		dev_info(&pdev->dev, "gpio-mosi property not found, switching to no-tx mode\n");
-		pdata->mosi = SPI_GPIO_NO_MOSI;
-	} else
-		pdata->mosi = ret;
-
-	ret = of_property_read_u32(np, "num-chipselects", &tmp);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "num-chipselects property not found\n");
-		goto error_free;
-	}
-
-	pdata->num_chipselect = tmp;
-	pdev->dev.platform_data = pdata;
-
-	return 1;
 
-error_free:
-	devm_kfree(&pdev->dev, pdata);
-	return ret;
-}
-#else
-static inline int spi_gpio_probe_dt(struct platform_device *pdev)
-{
 	return 0;
 }
-#endif
 
 static int spi_gpio_probe(struct platform_device *pdev)
 {
 	int				status;
-	struct spi_master		*master;
+	struct spi_controller		*host;
 	struct spi_gpio			*spi_gpio;
-	struct spi_gpio_platform_data	*pdata;
-	u16 master_flags = 0;
-	bool use_of = 0;
+	struct device			*dev = &pdev->dev;
+	struct fwnode_handle		*fwnode = dev_fwnode(dev);
+	struct spi_bitbang		*bb;
 
-	status = spi_gpio_probe_dt(pdev);
-	if (status < 0)
-		return status;
-	if (status > 0)
-		use_of = 1;
+	host = devm_spi_alloc_host(dev, sizeof(*spi_gpio));
+	if (!host)
+		return -ENOMEM;
 
-	pdata = pdev->dev.platform_data;
-#ifdef GENERIC_BITBANG
-	if (!pdata || !pdata->num_chipselect)
-		return -ENODEV;
-#endif
+	if (fwnode) {
+		device_set_node(&host->dev, fwnode);
+		host->use_gpio_descriptors = true;
+	} else {
+		status = spi_gpio_probe_pdata(pdev, host);
+		if (status)
+			return status;
+	}
+
+	spi_gpio = spi_controller_get_devdata(host);
 
-	status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags);
-	if (status < 0)
+	status = spi_gpio_request(dev, spi_gpio);
+	if (status)
 		return status;
 
-	master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) +
-					(sizeof(int) * SPI_N_CHIPSEL));
-	if (!master) {
-		status = -ENOMEM;
-		goto gpio_free;
-	}
-	spi_gpio = spi_master_get_devdata(master);
-	platform_set_drvdata(pdev, spi_gpio);
-
-	spi_gpio->pdev = pdev;
-	if (pdata)
-		spi_gpio->pdata = *pdata;
-
-	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
-	master->flags = master_flags;
-	master->bus_num = pdev->id;
-	master->num_chipselect = SPI_N_CHIPSEL;
-	master->setup = spi_gpio_setup;
-	master->cleanup = spi_gpio_cleanup;
-#ifdef CONFIG_OF
-	master->dev.of_node = pdev->dev.of_node;
-
-	if (use_of) {
-		int i;
-		struct device_node *np = pdev->dev.of_node;
-
-		/*
-		 * In DT environments, take the CS GPIO from the "cs-gpios"
-		 * property of the node.
+	host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
+	host->mode_bits = SPI_3WIRE | SPI_3WIRE_HIZ | SPI_CPHA | SPI_CPOL |
+			  SPI_CS_HIGH | SPI_LSB_FIRST | SPI_MOSI_IDLE_LOW |
+			  SPI_MOSI_IDLE_HIGH;
+	if (!spi_gpio->mosi) {
+		/* HW configuration without MOSI pin
+		 *
+		 * No setting SPI_CONTROLLER_NO_RX here - if there is only
+		 * a MOSI pin connected the host can still do RX by
+		 * changing the direction of the line.
 		 */
-
-		for (i = 0; i < SPI_N_CHIPSEL; i++)
-			spi_gpio->cs_gpios[i] =
-				of_get_named_gpio(np, "cs-gpios", i);
+		host->flags = SPI_CONTROLLER_NO_TX;
 	}
-#endif
-
-	spi_gpio->bitbang.master = spi_master_get(master);
-	spi_gpio->bitbang.chipselect = spi_gpio_chipselect;
 
-	if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) {
-		spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0;
-		spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1;
-		spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
-		spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
+	host->bus_num = pdev->id;
+	host->setup = spi_gpio_setup;
+	host->cleanup = spi_gpio_cleanup;
+
+	bb = &spi_gpio->bitbang;
+	bb->ctlr = host;
+	/*
+	 * There is some additional business, apart from driving the CS GPIO
+	 * line, that we need to do on selection. This makes the local
+	 * callback for chipselect always get called.
+	 */
+	host->flags |= SPI_CONTROLLER_GPIO_SS;
+	bb->chipselect = spi_gpio_chipselect;
+	bb->set_line_direction = spi_gpio_set_direction;
+	bb->set_mosi_idle = spi_gpio_set_mosi_idle;
+
+	if (host->flags & SPI_CONTROLLER_NO_TX) {
+		bb->txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0;
+		bb->txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1;
+		bb->txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2;
+		bb->txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3;
 	} else {
-		spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0;
-		spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1;
-		spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2;
-		spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3;
-	}
-	spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
-	spi_gpio->bitbang.flags = SPI_CS_HIGH;
-
-	status = spi_bitbang_start(&spi_gpio->bitbang);
-	if (status < 0) {
-		spi_master_put(spi_gpio->bitbang.master);
-gpio_free:
-		if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
-			gpio_free(SPI_MISO_GPIO);
-		if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
-			gpio_free(SPI_MOSI_GPIO);
-		gpio_free(SPI_SCK_GPIO);
-		spi_master_put(master);
+		bb->txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0;
+		bb->txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1;
+		bb->txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
+		bb->txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
 	}
+	bb->setup_transfer = spi_bitbang_setup_transfer;
 
-	return status;
-}
-
-static int spi_gpio_remove(struct platform_device *pdev)
-{
-	struct spi_gpio			*spi_gpio;
-	struct spi_gpio_platform_data	*pdata;
-	int				status;
-
-	spi_gpio = platform_get_drvdata(pdev);
-	pdata = pdev->dev.platform_data;
-
-	/* stop() unregisters child devices too */
-	status = spi_bitbang_stop(&spi_gpio->bitbang);
-	spi_master_put(spi_gpio->bitbang.master);
-
-	if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
-		gpio_free(SPI_MISO_GPIO);
-	if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
-		gpio_free(SPI_MOSI_GPIO);
-	gpio_free(SPI_SCK_GPIO);
+	status = spi_bitbang_init(&spi_gpio->bitbang);
+	if (status)
+		return status;
 
-	return status;
+	return devm_spi_register_controller(&pdev->dev, host);
 }
 
-MODULE_ALIAS("platform:" DRIVER_NAME);
+static const struct of_device_id spi_gpio_dt_ids[] = {
+	{ .compatible = "spi-gpio" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids);
 
 static struct platform_driver spi_gpio_driver = {
 	.driver = {
 		.name	= DRIVER_NAME,
-		.owner	= THIS_MODULE,
-		.of_match_table = of_match_ptr(spi_gpio_dt_ids),
+		.of_match_table = spi_gpio_dt_ids,
 	},
 	.probe		= spi_gpio_probe,
-	.remove		= spi_gpio_remove,
 };
 module_platform_driver(spi_gpio_driver);
 
-MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO ");
+MODULE_DESCRIPTION("SPI host driver using generic bitbanged GPIO ");
 MODULE_AUTHOR("David Brownell");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);