[PATCH v3 2/3] spi: add FTDI MPSSE SPI controller driver

From: Anatolij Gustschin
Date: Tue Nov 27 2018 - 12:54:53 EST


Add SPI bus controller driver for FTDI MPSSE mode. This driver
is supposed to be used together with the FT232H interface driver
for FPGA configuration in drivers/usb/misc/ft232h-intf.c which
adds an mpsse spi platform device describing USB SPI bus with
attached SPI slave devices.

Signed-off-by: Anatolij Gustschin <agust@xxxxxxx>
---
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-ftdi-mpsse.c | 651 +++++++++++++++++++++++++++++++++++
3 files changed, 659 insertions(+)
create mode 100644 drivers/spi/spi-ftdi-mpsse.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7d3a5c94727e..2cb24e28c485 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -259,6 +259,13 @@ config SPI_FSL_LPSPI
help
This enables Freescale i.MX LPSPI controllers in master mode.

+config SPI_FTDI_MPSSE
+ tristate "FTDI MPSSE SPI controller"
+ depends on USB_FT232H_INTF || COMPILE_TEST
+ help
+ FT232H supports SPI in MPSSE mode. This driver provides MPSSE
+ SPI controller in master mode.
+
config SPI_GPIO
tristate "GPIO-based bitbanging SPI Master"
depends on GPIOLIB || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3575205c5c27..065240a02b31 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_SPI_FSL_LIB) += spi-fsl-lib.o
obj-$(CONFIG_SPI_FSL_ESPI) += spi-fsl-espi.o
obj-$(CONFIG_SPI_FSL_LPSPI) += spi-fsl-lpspi.o
obj-$(CONFIG_SPI_FSL_SPI) += spi-fsl-spi.o
+obj-$(CONFIG_SPI_FTDI_MPSSE) += spi-ftdi-mpsse.o
obj-$(CONFIG_SPI_GPIO) += spi-gpio.o
obj-$(CONFIG_SPI_IMG_SPFI) += spi-img-spfi.o
obj-$(CONFIG_SPI_IMX) += spi-imx.o
diff --git a/drivers/spi/spi-ftdi-mpsse.c b/drivers/spi/spi-ftdi-mpsse.c
new file mode 100644
index 000000000000..ae8442eb4052
--- /dev/null
+++ b/drivers/spi/spi-ftdi-mpsse.c
@@ -0,0 +1,651 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// FTDI FT232H MPSSE SPI controller driver
+//
+// Copyright (C) 2017 - 2018 DENX Software Engineering
+// Anatolij Gustschin <agust@xxxxxxx>
+//
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/machine.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/sizes.h>
+#include <linux/usb.h>
+#include <linux/usb/ft232h-intf.h>
+
+enum gpiol {
+ MPSSE_SK = BIT(0),
+ MPSSE_DO = BIT(1),
+ MPSSE_DI = BIT(2),
+ MPSSE_CS = BIT(3),
+};
+
+struct ftdi_spi {
+ struct platform_device *pdev;
+ struct usb_interface *intf;
+ struct spi_controller *master;
+ const struct ft232h_intf_ops *iops;
+ struct gpiod_lookup_table *lookup[FTDI_MPSSE_GPIOS];
+ struct gpio_desc **cs_gpios;
+
+ u8 txrx_cmd;
+ u8 rx_cmd;
+ u8 tx_cmd;
+ u8 xfer_buf[SZ_64K];
+ u16 last_mode;
+};
+
+static void ftdi_spi_set_cs(struct spi_device *spi, bool enable)
+{
+ struct ftdi_spi *priv = spi_controller_get_devdata(spi->master);
+ u16 cs = spi->chip_select;
+
+ dev_dbg(&priv->pdev->dev, "%s: CS %u, cs mode %d, val %d\n",
+ __func__, cs, (spi->mode & SPI_CS_HIGH), enable);
+
+ gpiod_set_raw_value_cansleep(priv->cs_gpios[cs], enable);
+}
+
+static inline u8 ftdi_spi_txrx_byte_cmd(struct spi_device *spi)
+{
+ u8 mode = spi->mode & (SPI_CPOL | SPI_CPHA);
+ u8 cmd;
+
+ if (spi->mode & SPI_LSB_FIRST) {
+ switch (mode) {
+ case SPI_MODE_0:
+ case SPI_MODE_1:
+ cmd = TXF_RXR_BYTES_LSB;
+ break;
+ case SPI_MODE_2:
+ case SPI_MODE_3:
+ cmd = TXR_RXF_BYTES_LSB;
+ break;
+ }
+ } else {
+ switch (mode) {
+ case SPI_MODE_0:
+ case SPI_MODE_1:
+ cmd = TXF_RXR_BYTES_MSB;
+ break;
+ case SPI_MODE_2:
+ case SPI_MODE_3:
+ cmd = TXR_RXF_BYTES_MSB;
+ break;
+ }
+ }
+ return cmd;
+}
+
+static inline int ftdi_spi_loopback_cfg(struct ftdi_spi *priv, int on)
+{
+ int ret;
+
+ priv->xfer_buf[0] = on ? LOOPBACK_ON : LOOPBACK_OFF;
+
+ ret = priv->iops->write_data(priv->intf, priv->xfer_buf, 1);
+ if (ret < 0)
+ dev_warn(&priv->pdev->dev, "loopback %d failed\n", on);
+ return ret;
+}
+
+static int ftdi_spi_tx_rx(struct ftdi_spi *priv, struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ const struct ft232h_intf_ops *ops = priv->iops;
+ struct device *dev = &priv->pdev->dev;
+ void *rx_offs;
+ const void *tx_offs;
+ size_t remaining, stride;
+ size_t rx_stride;
+ int ret, tout = 10;
+ const u8 *tx_data = t->tx_buf;
+ u8 *rx_data = t->rx_buf;
+
+ ops->lock(priv->intf);
+
+ if (spi->mode & SPI_LOOP) {
+ ret = ftdi_spi_loopback_cfg(priv, 1);
+ if (ret < 0)
+ goto err;
+ }
+
+ remaining = t->len;
+ rx_offs = rx_data;
+ tx_offs = tx_data;
+
+ while (remaining) {
+ stride = min_t(size_t, remaining, SZ_512 - 3);
+
+ priv->xfer_buf[0] = priv->txrx_cmd;
+ priv->xfer_buf[1] = stride - 1;
+ priv->xfer_buf[2] = (stride - 1) >> 8;
+ memcpy(&priv->xfer_buf[3], tx_offs, stride);
+ print_hex_dump_debug("WR: ", DUMP_PREFIX_OFFSET, 16, 1,
+ priv->xfer_buf, stride + 3, 1);
+
+ ret = ops->write_data(priv->intf, priv->xfer_buf, stride + 3);
+ if (ret < 0) {
+ dev_err(dev, "%s: xfer failed %d\n", __func__, ret);
+ goto fail;
+ }
+ dev_dbg(dev, "%s: WR %zu byte(s), TXRX CMD 0x%02x\n",
+ __func__, stride, priv->txrx_cmd);
+
+ rx_stride = min_t(size_t, stride, SZ_512);
+
+ ret = ops->read_data(priv->intf, priv->xfer_buf, rx_stride);
+ while (ret == 0) {
+ /* If no data yet, wait and repeat */
+ usleep_range(5000, 5100);
+ ret = ops->read_data(priv->intf, priv->xfer_buf,
+ rx_stride);
+ dev_dbg(dev, "Waiting data ready, read: %d\n", ret);
+ if (!--tout) {
+ dev_err(dev, "Read timeout\n");
+ ret = -ETIMEDOUT;
+ goto fail;
+ }
+ }
+
+ if (ret < 0)
+ goto fail;
+
+ print_hex_dump_debug("RD: ", DUMP_PREFIX_OFFSET, 16, 1,
+ priv->xfer_buf, rx_stride, 1);
+ memcpy(rx_offs, priv->xfer_buf, ret);
+ rx_offs += ret;
+
+ remaining -= stride;
+ tx_offs += stride;
+ dev_dbg(dev, "%s: WR remains %zu\n", __func__, remaining);
+ }
+
+ ret = 0;
+
+fail:
+ if (spi->mode & SPI_LOOP)
+ ftdi_spi_loopback_cfg(priv, 0);
+
+err:
+ ops->unlock(priv->intf);
+ return ret;
+}
+
+static int ftdi_spi_push_buf(struct ftdi_spi *priv, const void *buf, size_t len)
+{
+ size_t bytesleft = len;
+ int ret;
+
+ do {
+ ret = priv->iops->write_data(priv->intf, buf, bytesleft);
+ if (ret < 0)
+ return ret;
+
+ buf += ret;
+ bytesleft -= ret;
+ } while (bytesleft);
+
+ return len;
+}
+
+static int ftdi_spi_tx(struct ftdi_spi *priv, struct spi_transfer *xfer)
+{
+ const void *tx_offs;
+ size_t remaining, stride;
+ int ret;
+
+ priv->iops->lock(priv->intf);
+
+ tx_offs = xfer->tx_buf;
+ remaining = xfer->len;
+
+ do {
+ stride = min_t(size_t, remaining, sizeof(priv->xfer_buf) - 3);
+
+ priv->xfer_buf[0] = priv->tx_cmd;
+ priv->xfer_buf[1] = stride - 1;
+ priv->xfer_buf[2] = (stride - 1) >> 8;
+
+ memcpy(&priv->xfer_buf[3], tx_offs, stride);
+
+ ret = ftdi_spi_push_buf(priv, priv->xfer_buf, stride + 3);
+ if (ret < 0) {
+ dev_dbg(&priv->pdev->dev, "%s: tx failed %d\n",
+ __func__, ret);
+ goto err;
+ }
+ dev_dbg(&priv->pdev->dev, "%s: %zu byte(s) done\n",
+ __func__, stride);
+ remaining -= stride;
+ tx_offs += stride;
+ } while (remaining);
+
+ ret = 0;
+err:
+ priv->iops->unlock(priv->intf);
+ return ret;
+}
+
+static int ftdi_spi_rx(struct ftdi_spi *priv, struct spi_transfer *xfer)
+{
+ const struct ft232h_intf_ops *ops = priv->iops;
+ struct device *dev = &priv->pdev->dev;
+ size_t remaining, stride;
+ int ret, tout = 10;
+ void *rx_offs;
+
+ dev_dbg(dev, "%s: CMD 0x%02x, len %u\n",
+ __func__, priv->rx_cmd, xfer->len);
+
+ priv->xfer_buf[0] = priv->rx_cmd;
+ priv->xfer_buf[1] = xfer->len - 1;
+ priv->xfer_buf[2] = (xfer->len - 1) >> 8;
+
+ ops->lock(priv->intf);
+
+ ret = ops->write_data(priv->intf, priv->xfer_buf, 3);
+ if (ret < 0)
+ goto err;
+
+ remaining = xfer->len;
+ rx_offs = xfer->rx_buf;
+
+ do {
+ stride = min_t(size_t, remaining, SZ_512);
+
+ ret = ops->read_data(priv->intf, priv->xfer_buf, stride);
+ if (ret < 0)
+ goto err;
+
+ if (!ret) {
+ dev_dbg(dev, "Waiting for data (read: %02X), tout %d\n",
+ ret, tout);
+ if (--tout)
+ continue;
+
+ dev_dbg(dev, "read timeout...\n");
+ ret = -ETIMEDOUT;
+ goto err;
+ }
+
+ memcpy(rx_offs, priv->xfer_buf, ret);
+
+ dev_dbg(dev, "%s: %d byte(s)\n", __func__, ret);
+ rx_offs += ret;
+ remaining -= ret;
+ } while (remaining);
+
+ ret = 0;
+err:
+ ops->unlock(priv->intf);
+ return ret;
+}
+
+static int ftdi_spi_transfer_one(struct spi_controller *ctlr,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct ftdi_spi *priv = spi_controller_get_devdata(ctlr);
+ struct device *dev = &priv->pdev->dev;
+ int ret = 0;
+
+ if (!xfer->len)
+ return 0;
+
+ if (priv->last_mode != spi->mode) {
+ u8 spi_mode = spi->mode & (SPI_CPOL | SPI_CPHA);
+ u8 pins = 0;
+
+ dev_dbg(dev, "%s: MODE 0x%x\n", __func__, spi->mode);
+
+ if (spi->mode & SPI_LSB_FIRST) {
+ switch (spi_mode) {
+ case SPI_MODE_0:
+ case SPI_MODE_3:
+ priv->tx_cmd = TX_BYTES_FE_LSB;
+ priv->rx_cmd = RX_BYTES_RE_LSB;
+ break;
+ case SPI_MODE_1:
+ case SPI_MODE_2:
+ priv->tx_cmd = TX_BYTES_RE_LSB;
+ priv->rx_cmd = RX_BYTES_FE_LSB;
+ break;
+ }
+ } else {
+ switch (spi_mode) {
+ case SPI_MODE_0:
+ case SPI_MODE_3:
+ priv->tx_cmd = TX_BYTES_FE_MSB;
+ priv->rx_cmd = RX_BYTES_RE_MSB;
+ break;
+ case SPI_MODE_1:
+ case SPI_MODE_2:
+ priv->tx_cmd = TX_BYTES_RE_MSB;
+ priv->rx_cmd = RX_BYTES_FE_MSB;
+ break;
+ }
+ }
+
+ priv->txrx_cmd = ftdi_spi_txrx_byte_cmd(spi);
+
+ switch (spi_mode) {
+ case SPI_MODE_2:
+ case SPI_MODE_3:
+ pins |= MPSSE_SK;
+ break;
+ }
+
+ ret = priv->iops->cfg_bus_pins(priv->intf,
+ MPSSE_SK | MPSSE_DO, pins);
+ if (ret < 0) {
+ dev_err(dev, "IO cfg failed: %d\n", ret);
+ return ret;
+ }
+ priv->last_mode = spi->mode;
+ }
+
+ dev_dbg(dev, "%s: mode 0x%x, CMD RX/TX 0x%x/0x%x\n",
+ __func__, spi->mode, priv->rx_cmd, priv->tx_cmd);
+
+ if (xfer->tx_buf && xfer->rx_buf)
+ ret = ftdi_spi_tx_rx(priv, spi, xfer);
+ else if (xfer->tx_buf)
+ ret = ftdi_spi_tx(priv, xfer);
+ else if (xfer->rx_buf)
+ ret = ftdi_spi_rx(priv, xfer);
+
+ dev_dbg(dev, "%s: xfer ret %d\n", __func__, ret);
+
+ spi_finalize_current_transfer(ctlr);
+ return ret;
+}
+
+static int ftdi_mpsse_init(struct ftdi_spi *priv)
+{
+ struct platform_device *pdev = priv->pdev;
+ int ret;
+
+ dev_dbg(&pdev->dev, "MPSSE init\n");
+
+ /* Setup and send off the Hi-Speed specific commands for the FTx232H */
+ priv->xfer_buf[0] = DIS_DIV_5; /* Use 60MHz master clock */
+ priv->xfer_buf[1] = DIS_ADAPTIVE; /* Turn off adaptive clocking */
+ priv->xfer_buf[2] = DIS_3_PHASE; /* Disable three-phase clocking */
+
+ priv->iops->lock(priv->intf);
+
+ ret = priv->iops->write_data(priv->intf, priv->xfer_buf, 3);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Clk cfg failed: %d\n", ret);
+ priv->iops->unlock(priv->intf);
+ return ret;
+ }
+
+ priv->xfer_buf[0] = TCK_DIVISOR;
+ priv->xfer_buf[1] = div_value(60000000);
+ priv->xfer_buf[2] = div_value(60000000) >> 8;
+ dev_dbg(&pdev->dev, "TCK_DIVISOR: 0x%04x 0x%04x\n",
+ priv->xfer_buf[1], priv->xfer_buf[2]);
+
+ ret = priv->iops->write_data(priv->intf, priv->xfer_buf, 3);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Clk cfg failed: %d\n", ret);
+ priv->iops->unlock(priv->intf);
+ return ret;
+ }
+
+ priv->iops->unlock(priv->intf);
+
+ ret = priv->iops->cfg_bus_pins(priv->intf, MPSSE_SK | MPSSE_DO, 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Can't init SPI bus pins: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ftdi_spi_init_io(struct spi_controller *master, unsigned int dev_idx)
+{
+ struct ftdi_spi *priv = spi_controller_get_devdata(master);
+ struct platform_device *pdev = priv->pdev;
+ const struct mpsse_spi_platform_data *pd;
+ const struct mpsse_spi_dev_data *data;
+ struct gpiod_lookup_table *lookup;
+ size_t lookup_size, size;
+ char *label;
+ unsigned int i;
+ u16 cs;
+
+ pd = pdev->dev.platform_data;
+
+ data = pd->spi_info[dev_idx].platform_data;
+ if (!data || data->magic != FTDI_MPSSE_IO_DESC_MAGIC)
+ return 0;
+
+ size = data->desc_len + 1;
+
+ lookup_size = sizeof(*lookup) + size * sizeof(struct gpiod_lookup);
+ lookup = devm_kzalloc(&pdev->dev, lookup_size, GFP_KERNEL);
+ if (!lookup)
+ return -ENOMEM;
+
+ cs = pd->spi_info[dev_idx].chip_select;
+
+ lookup->dev_id = devm_kasprintf(&pdev->dev, GFP_KERNEL, "spi%d.%d",
+ master->bus_num, cs);
+ if (!lookup->dev_id) {
+ devm_kfree(&pdev->dev, lookup);
+ return -ENOMEM;
+ }
+ dev_dbg(&pdev->dev, "LOOKUP ID '%s'\n", lookup->dev_id);
+
+ label = devm_kasprintf(&pdev->dev, GFP_KERNEL, "ftdi-mpsse-gpio.%d",
+ pdev->id);
+ if (!label) {
+ devm_kfree(&pdev->dev, (void *)lookup->dev_id);
+ devm_kfree(&pdev->dev, lookup);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < data->desc_len; i++) {
+ dev_dbg(&pdev->dev, "con_id: '%s' idx: %d, flags: 0x%x\n",
+ data->desc[i].con_id, data->desc[i].idx,
+ data->desc[i].flags);
+ lookup->table[i].chip_label = label;
+ lookup->table[i].chip_hwnum = data->desc[i].idx;
+ lookup->table[i].idx = 0;
+ lookup->table[i].con_id = data->desc[i].con_id;
+ lookup->table[i].flags = data->desc[i].flags;
+ }
+
+ priv->lookup[cs] = lookup;
+ gpiod_add_lookup_table(lookup);
+ return 0;
+}
+
+static int ftdi_spi_probe(struct platform_device *pdev)
+{
+ const struct mpsse_spi_platform_data *pd;
+ struct device *dev = &pdev->dev;
+ struct spi_controller *master;
+ struct ftdi_spi *priv;
+ struct gpio_desc *desc;
+ u16 num_cs, max_cs = 0;
+ unsigned int i;
+ int ret;
+
+ pd = dev->platform_data;
+ if (!pd) {
+ dev_err(dev, "Missing platform data.\n");
+ return -EINVAL;
+ }
+
+ if (!pd->ops ||
+ !pd->ops->read_data || !pd->ops->write_data ||
+ !pd->ops->lock || !pd->ops->unlock ||
+ !pd->ops->set_bitmode || !pd->ops->set_baudrate ||
+ !pd->ops->disable_bitbang || !pd->ops->cfg_bus_pins)
+ return -EINVAL;
+
+ if (pd->spi_info_len > FTDI_MPSSE_GPIOS)
+ return -EINVAL;
+
+ /* Find max. slave chipselect number */
+ num_cs = pd->spi_info_len;
+ for (i = 0; i < num_cs; i++) {
+ if (max_cs < pd->spi_info[i].chip_select)
+ max_cs = pd->spi_info[i].chip_select;
+ }
+
+ if (max_cs > FTDI_MPSSE_GPIOS - 1) {
+ dev_err(dev, "Invalid max CS in platform data: %u\n", max_cs);
+ return -EINVAL;
+ }
+ dev_dbg(dev, "CS count %u, max CS %u\n", num_cs, max_cs);
+ max_cs += 1; /* including CS0 */
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*priv));
+ if (!master)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, master);
+
+ priv = spi_controller_get_devdata(master);
+ priv->master = master;
+ priv->pdev = pdev;
+ priv->intf = to_usb_interface(dev->parent);
+ priv->iops = pd->ops;
+
+ master->bus_num = -1;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP |
+ SPI_CS_HIGH | SPI_LSB_FIRST;
+ master->num_chipselect = max_cs;
+ master->min_speed_hz = 450;
+ master->max_speed_hz = 30000000;
+ master->bits_per_word_mask = SPI_BPW_MASK(8);
+ master->set_cs = ftdi_spi_set_cs;
+ master->transfer_one = ftdi_spi_transfer_one;
+ master->auto_runtime_pm = false;
+
+ priv->cs_gpios = devm_kcalloc(&master->dev, max_cs, sizeof(desc),
+ GFP_KERNEL);
+ if (!priv->cs_gpios) {
+ spi_controller_put(master);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < num_cs; i++) {
+ unsigned int idx = pd->spi_info[i].chip_select;
+
+ dev_dbg(&pdev->dev, "CS num: %u\n", idx);
+ desc = devm_gpiod_get_index(&priv->pdev->dev, "spi-cs",
+ i, GPIOD_OUT_LOW);
+ if (IS_ERR(desc)) {
+ ret = PTR_ERR(desc);
+ dev_err(&pdev->dev, "CS %u gpiod err: %d\n", i, ret);
+ continue;
+ }
+ priv->cs_gpios[idx] = desc;
+ }
+
+ ret = spi_register_controller(master);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to register spi master\n");
+ spi_controller_put(master);
+ return ret;
+ }
+
+ ret = priv->iops->set_bitmode(priv->intf, 0x00, BITMODE_MPSSE);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to set MPSSE mode\n");
+ goto err;
+ }
+
+ priv->last_mode = 0xffff;
+
+ ret = ftdi_mpsse_init(priv);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "MPSSE init failed\n");
+ goto err;
+ }
+
+ for (i = 0; i < pd->spi_info_len; i++) {
+ struct spi_device *sdev;
+ u16 cs;
+
+ dev_dbg(&pdev->dev, "slave: '%s', CS: %u\n",
+ pd->spi_info[i].modalias, pd->spi_info[i].chip_select);
+
+ ret = ftdi_spi_init_io(master, i);
+ if (ret < 0) {
+ dev_warn(&pdev->dev, "Can't add slave IO: %d\n", ret);
+ continue;
+ }
+ sdev = spi_new_device(master, &pd->spi_info[i]);
+ if (!sdev) {
+ cs = pd->spi_info[i].chip_select;
+ dev_warn(&pdev->dev, "Can't add slave '%s', CS %u\n",
+ pd->spi_info[i].modalias, cs);
+ if (priv->lookup[cs]) {
+ gpiod_remove_lookup_table(priv->lookup[cs]);
+ priv->lookup[cs] = NULL;
+ }
+ }
+ }
+
+ return 0;
+err:
+ platform_set_drvdata(pdev, NULL);
+ spi_unregister_controller(master);
+ return ret;
+}
+
+static int ftdi_spi_slave_release(struct device *dev, void *data)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct ftdi_spi *priv = data;
+ u16 cs = spi->chip_select;
+
+ dev_dbg(dev, "%s: remove CS %u\n", __func__, cs);
+ spi_unregister_device(to_spi_device(dev));
+
+ if (priv->lookup[cs])
+ gpiod_remove_lookup_table(priv->lookup[cs]);
+ return 0;
+}
+
+static int ftdi_spi_remove(struct platform_device *pdev)
+{
+ struct spi_controller *master;
+ struct ftdi_spi *priv;
+
+ master = platform_get_drvdata(pdev);
+ priv = spi_controller_get_devdata(master);
+
+ device_for_each_child(&master->dev, priv, ftdi_spi_slave_release);
+
+ spi_unregister_controller(master);
+ return 0;
+}
+
+static struct platform_driver ftdi_spi_driver = {
+ .driver.name = "ftdi-mpsse-spi",
+ .probe = ftdi_spi_probe,
+ .remove = ftdi_spi_remove,
+};
+module_platform_driver(ftdi_spi_driver);
+
+MODULE_ALIAS("platform:ftdi-mpsse-spi");
+MODULE_AUTHOR("Anatolij Gustschin <agust@xxxxxxx");
+MODULE_DESCRIPTION("FTDI MPSSE SPI master driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1