diff options
Diffstat (limited to 'drivers/spi/spi-dln2.c')
| -rw-r--r-- | drivers/spi/spi-dln2.c | 880 |
1 files changed, 880 insertions, 0 deletions
diff --git a/drivers/spi/spi-dln2.c b/drivers/spi/spi-dln2.c new file mode 100644 index 000000000..9a4d942fa --- /dev/null +++ b/drivers/spi/spi-dln2.c @@ -0,0 +1,880 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for the Diolan DLN-2 USB-SPI adapter + * + * Copyright (c) 2014 Intel Corporation + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/mfd/dln2.h> +#include <linux/spi/spi.h> +#include <linux/pm_runtime.h> +#include <asm/unaligned.h> + +#define DLN2_SPI_MODULE_ID 0x02 +#define DLN2_SPI_CMD(cmd) DLN2_CMD(cmd, DLN2_SPI_MODULE_ID) + +/* SPI commands */ +#define DLN2_SPI_GET_PORT_COUNT DLN2_SPI_CMD(0x00) +#define DLN2_SPI_ENABLE DLN2_SPI_CMD(0x11) +#define DLN2_SPI_DISABLE DLN2_SPI_CMD(0x12) +#define DLN2_SPI_IS_ENABLED DLN2_SPI_CMD(0x13) +#define DLN2_SPI_SET_MODE DLN2_SPI_CMD(0x14) +#define DLN2_SPI_GET_MODE DLN2_SPI_CMD(0x15) +#define DLN2_SPI_SET_FRAME_SIZE DLN2_SPI_CMD(0x16) +#define DLN2_SPI_GET_FRAME_SIZE DLN2_SPI_CMD(0x17) +#define DLN2_SPI_SET_FREQUENCY DLN2_SPI_CMD(0x18) +#define DLN2_SPI_GET_FREQUENCY DLN2_SPI_CMD(0x19) +#define DLN2_SPI_READ_WRITE DLN2_SPI_CMD(0x1A) +#define DLN2_SPI_READ DLN2_SPI_CMD(0x1B) +#define DLN2_SPI_WRITE DLN2_SPI_CMD(0x1C) +#define DLN2_SPI_SET_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x20) +#define DLN2_SPI_GET_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x21) +#define DLN2_SPI_SET_DELAY_AFTER_SS DLN2_SPI_CMD(0x22) +#define DLN2_SPI_GET_DELAY_AFTER_SS DLN2_SPI_CMD(0x23) +#define DLN2_SPI_SET_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x24) +#define DLN2_SPI_GET_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x25) +#define DLN2_SPI_SET_SS DLN2_SPI_CMD(0x26) +#define DLN2_SPI_GET_SS DLN2_SPI_CMD(0x27) +#define DLN2_SPI_RELEASE_SS DLN2_SPI_CMD(0x28) +#define DLN2_SPI_SS_VARIABLE_ENABLE DLN2_SPI_CMD(0x2B) +#define DLN2_SPI_SS_VARIABLE_DISABLE DLN2_SPI_CMD(0x2C) +#define DLN2_SPI_SS_VARIABLE_IS_ENABLED DLN2_SPI_CMD(0x2D) +#define DLN2_SPI_SS_AAT_ENABLE DLN2_SPI_CMD(0x2E) +#define DLN2_SPI_SS_AAT_DISABLE DLN2_SPI_CMD(0x2F) +#define DLN2_SPI_SS_AAT_IS_ENABLED DLN2_SPI_CMD(0x30) +#define DLN2_SPI_SS_BETWEEN_FRAMES_ENABLE DLN2_SPI_CMD(0x31) +#define DLN2_SPI_SS_BETWEEN_FRAMES_DISABLE DLN2_SPI_CMD(0x32) +#define DLN2_SPI_SS_BETWEEN_FRAMES_IS_ENABLED DLN2_SPI_CMD(0x33) +#define DLN2_SPI_SET_CPHA DLN2_SPI_CMD(0x34) +#define DLN2_SPI_GET_CPHA DLN2_SPI_CMD(0x35) +#define DLN2_SPI_SET_CPOL DLN2_SPI_CMD(0x36) +#define DLN2_SPI_GET_CPOL DLN2_SPI_CMD(0x37) +#define DLN2_SPI_SS_MULTI_ENABLE DLN2_SPI_CMD(0x38) +#define DLN2_SPI_SS_MULTI_DISABLE DLN2_SPI_CMD(0x39) +#define DLN2_SPI_SS_MULTI_IS_ENABLED DLN2_SPI_CMD(0x3A) +#define DLN2_SPI_GET_SUPPORTED_MODES DLN2_SPI_CMD(0x40) +#define DLN2_SPI_GET_SUPPORTED_CPHA_VALUES DLN2_SPI_CMD(0x41) +#define DLN2_SPI_GET_SUPPORTED_CPOL_VALUES DLN2_SPI_CMD(0x42) +#define DLN2_SPI_GET_SUPPORTED_FRAME_SIZES DLN2_SPI_CMD(0x43) +#define DLN2_SPI_GET_SS_COUNT DLN2_SPI_CMD(0x44) +#define DLN2_SPI_GET_MIN_FREQUENCY DLN2_SPI_CMD(0x45) +#define DLN2_SPI_GET_MAX_FREQUENCY DLN2_SPI_CMD(0x46) +#define DLN2_SPI_GET_MIN_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x47) +#define DLN2_SPI_GET_MAX_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x48) +#define DLN2_SPI_GET_MIN_DELAY_AFTER_SS DLN2_SPI_CMD(0x49) +#define DLN2_SPI_GET_MAX_DELAY_AFTER_SS DLN2_SPI_CMD(0x4A) +#define DLN2_SPI_GET_MIN_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x4B) +#define DLN2_SPI_GET_MAX_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x4C) + +#define DLN2_SPI_MAX_XFER_SIZE 256 +#define DLN2_SPI_BUF_SIZE (DLN2_SPI_MAX_XFER_SIZE + 16) +#define DLN2_SPI_ATTR_LEAVE_SS_LOW BIT(0) +#define DLN2_TRANSFERS_WAIT_COMPLETE 1 +#define DLN2_TRANSFERS_CANCEL 0 +#define DLN2_RPM_AUTOSUSPEND_TIMEOUT 2000 + +struct dln2_spi { + struct platform_device *pdev; + struct spi_master *master; + u8 port; + + /* + * This buffer will be used mainly for read/write operations. Since + * they're quite large, we cannot use the stack. Protection is not + * needed because all SPI communication is serialized by the SPI core. + */ + void *buf; + + u8 bpw; + u32 speed; + u16 mode; + u8 cs; +}; + +/* + * Enable/Disable SPI module. The disable command will wait for transfers to + * complete first. + */ +static int dln2_spi_enable(struct dln2_spi *dln2, bool enable) +{ + u16 cmd; + struct { + u8 port; + u8 wait_for_completion; + } tx; + unsigned len = sizeof(tx); + + tx.port = dln2->port; + + if (enable) { + cmd = DLN2_SPI_ENABLE; + len -= sizeof(tx.wait_for_completion); + } else { + tx.wait_for_completion = DLN2_TRANSFERS_WAIT_COMPLETE; + cmd = DLN2_SPI_DISABLE; + } + + return dln2_transfer_tx(dln2->pdev, cmd, &tx, len); +} + +/* + * Select/unselect multiple CS lines. The selected lines will be automatically + * toggled LOW/HIGH by the board firmware during transfers, provided they're + * enabled first. + * + * Ex: cs_mask = 0x03 -> CS0 & CS1 will be selected and the next WR/RD operation + * will toggle the lines LOW/HIGH automatically. + */ +static int dln2_spi_cs_set(struct dln2_spi *dln2, u8 cs_mask) +{ + struct { + u8 port; + u8 cs; + } tx; + + tx.port = dln2->port; + + /* + * According to Diolan docs, "a slave device can be selected by changing + * the corresponding bit value to 0". The rest must be set to 1. Hence + * the bitwise NOT in front. + */ + tx.cs = ~cs_mask; + + return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_SS, &tx, sizeof(tx)); +} + +/* + * Select one CS line. The other lines will be un-selected. + */ +static int dln2_spi_cs_set_one(struct dln2_spi *dln2, u8 cs) +{ + return dln2_spi_cs_set(dln2, BIT(cs)); +} + +/* + * Enable/disable CS lines for usage. The module has to be disabled first. + */ +static int dln2_spi_cs_enable(struct dln2_spi *dln2, u8 cs_mask, bool enable) +{ + struct { + u8 port; + u8 cs; + } tx; + u16 cmd; + + tx.port = dln2->port; + tx.cs = cs_mask; + cmd = enable ? DLN2_SPI_SS_MULTI_ENABLE : DLN2_SPI_SS_MULTI_DISABLE; + + return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx)); +} + +static int dln2_spi_cs_enable_all(struct dln2_spi *dln2, bool enable) +{ + u8 cs_mask = GENMASK(dln2->master->num_chipselect - 1, 0); + + return dln2_spi_cs_enable(dln2, cs_mask, enable); +} + +static int dln2_spi_get_cs_num(struct dln2_spi *dln2, u16 *cs_num) +{ + int ret; + struct { + u8 port; + } tx; + struct { + __le16 cs_count; + } rx; + unsigned rx_len = sizeof(rx); + + tx.port = dln2->port; + ret = dln2_transfer(dln2->pdev, DLN2_SPI_GET_SS_COUNT, &tx, sizeof(tx), + &rx, &rx_len); + if (ret < 0) + return ret; + if (rx_len < sizeof(rx)) + return -EPROTO; + + *cs_num = le16_to_cpu(rx.cs_count); + + dev_dbg(&dln2->pdev->dev, "cs_num = %d\n", *cs_num); + + return 0; +} + +static int dln2_spi_get_speed(struct dln2_spi *dln2, u16 cmd, u32 *freq) +{ + int ret; + struct { + u8 port; + } tx; + struct { + __le32 speed; + } rx; + unsigned rx_len = sizeof(rx); + + tx.port = dln2->port; + + ret = dln2_transfer(dln2->pdev, cmd, &tx, sizeof(tx), &rx, &rx_len); + if (ret < 0) + return ret; + if (rx_len < sizeof(rx)) + return -EPROTO; + + *freq = le32_to_cpu(rx.speed); + + return 0; +} + +/* + * Get bus min/max frequencies. + */ +static int dln2_spi_get_speed_range(struct dln2_spi *dln2, u32 *fmin, u32 *fmax) +{ + int ret; + + ret = dln2_spi_get_speed(dln2, DLN2_SPI_GET_MIN_FREQUENCY, fmin); + if (ret < 0) + return ret; + + ret = dln2_spi_get_speed(dln2, DLN2_SPI_GET_MAX_FREQUENCY, fmax); + if (ret < 0) + return ret; + + dev_dbg(&dln2->pdev->dev, "freq_min = %d, freq_max = %d\n", + *fmin, *fmax); + + return 0; +} + +/* + * Set the bus speed. The module will automatically round down to the closest + * available frequency and returns it. The module has to be disabled first. + */ +static int dln2_spi_set_speed(struct dln2_spi *dln2, u32 speed) +{ + int ret; + struct { + u8 port; + __le32 speed; + } __packed tx; + struct { + __le32 speed; + } rx; + int rx_len = sizeof(rx); + + tx.port = dln2->port; + tx.speed = cpu_to_le32(speed); + + ret = dln2_transfer(dln2->pdev, DLN2_SPI_SET_FREQUENCY, &tx, sizeof(tx), + &rx, &rx_len); + if (ret < 0) + return ret; + if (rx_len < sizeof(rx)) + return -EPROTO; + + return 0; +} + +/* + * Change CPOL & CPHA. The module has to be disabled first. + */ +static int dln2_spi_set_mode(struct dln2_spi *dln2, u8 mode) +{ + struct { + u8 port; + u8 mode; + } tx; + + tx.port = dln2->port; + tx.mode = mode; + + return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_MODE, &tx, sizeof(tx)); +} + +/* + * Change frame size. The module has to be disabled first. + */ +static int dln2_spi_set_bpw(struct dln2_spi *dln2, u8 bpw) +{ + struct { + u8 port; + u8 bpw; + } tx; + + tx.port = dln2->port; + tx.bpw = bpw; + + return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_FRAME_SIZE, + &tx, sizeof(tx)); +} + +static int dln2_spi_get_supported_frame_sizes(struct dln2_spi *dln2, + u32 *bpw_mask) +{ + int ret; + struct { + u8 port; + } tx; + struct { + u8 count; + u8 frame_sizes[36]; + } *rx = dln2->buf; + unsigned rx_len = sizeof(*rx); + int i; + + tx.port = dln2->port; + + ret = dln2_transfer(dln2->pdev, DLN2_SPI_GET_SUPPORTED_FRAME_SIZES, + &tx, sizeof(tx), rx, &rx_len); + if (ret < 0) + return ret; + if (rx_len < sizeof(*rx)) + return -EPROTO; + if (rx->count > ARRAY_SIZE(rx->frame_sizes)) + return -EPROTO; + + *bpw_mask = 0; + for (i = 0; i < rx->count; i++) + *bpw_mask |= BIT(rx->frame_sizes[i] - 1); + + dev_dbg(&dln2->pdev->dev, "bpw_mask = 0x%X\n", *bpw_mask); + + return 0; +} + +/* + * Copy the data to DLN2 buffer and change the byte order to LE, requested by + * DLN2 module. SPI core makes sure that the data length is a multiple of word + * size. + */ +static int dln2_spi_copy_to_buf(u8 *dln2_buf, const u8 *src, u16 len, u8 bpw) +{ +#ifdef __LITTLE_ENDIAN + memcpy(dln2_buf, src, len); +#else + if (bpw <= 8) { + memcpy(dln2_buf, src, len); + } else if (bpw <= 16) { + __le16 *d = (__le16 *)dln2_buf; + u16 *s = (u16 *)src; + + len = len / 2; + while (len--) + *d++ = cpu_to_le16p(s++); + } else { + __le32 *d = (__le32 *)dln2_buf; + u32 *s = (u32 *)src; + + len = len / 4; + while (len--) + *d++ = cpu_to_le32p(s++); + } +#endif + + return 0; +} + +/* + * Copy the data from DLN2 buffer and convert to CPU byte order since the DLN2 + * buffer is LE ordered. SPI core makes sure that the data length is a multiple + * of word size. The RX dln2_buf is 2 byte aligned so, for BE, we have to make + * sure we avoid unaligned accesses for 32 bit case. + */ +static int dln2_spi_copy_from_buf(u8 *dest, const u8 *dln2_buf, u16 len, u8 bpw) +{ +#ifdef __LITTLE_ENDIAN + memcpy(dest, dln2_buf, len); +#else + if (bpw <= 8) { + memcpy(dest, dln2_buf, len); + } else if (bpw <= 16) { + u16 *d = (u16 *)dest; + __le16 *s = (__le16 *)dln2_buf; + + len = len / 2; + while (len--) + *d++ = le16_to_cpup(s++); + } else { + u32 *d = (u32 *)dest; + __le32 *s = (__le32 *)dln2_buf; + + len = len / 4; + while (len--) + *d++ = get_unaligned_le32(s++); + } +#endif + + return 0; +} + +/* + * Perform one write operation. + */ +static int dln2_spi_write_one(struct dln2_spi *dln2, const u8 *data, + u16 data_len, u8 attr) +{ + struct { + u8 port; + __le16 size; + u8 attr; + u8 buf[DLN2_SPI_MAX_XFER_SIZE]; + } __packed *tx = dln2->buf; + unsigned tx_len; + + BUILD_BUG_ON(sizeof(*tx) > DLN2_SPI_BUF_SIZE); + + if (data_len > DLN2_SPI_MAX_XFER_SIZE) + return -EINVAL; + + tx->port = dln2->port; + tx->size = cpu_to_le16(data_len); + tx->attr = attr; + + dln2_spi_copy_to_buf(tx->buf, data, data_len, dln2->bpw); + + tx_len = sizeof(*tx) + data_len - DLN2_SPI_MAX_XFER_SIZE; + return dln2_transfer_tx(dln2->pdev, DLN2_SPI_WRITE, tx, tx_len); +} + +/* + * Perform one read operation. + */ +static int dln2_spi_read_one(struct dln2_spi *dln2, u8 *data, + u16 data_len, u8 attr) +{ + int ret; + struct { + u8 port; + __le16 size; + u8 attr; + } __packed tx; + struct { + __le16 size; + u8 buf[DLN2_SPI_MAX_XFER_SIZE]; + } __packed *rx = dln2->buf; + unsigned rx_len = sizeof(*rx); + + BUILD_BUG_ON(sizeof(*rx) > DLN2_SPI_BUF_SIZE); + + if (data_len > DLN2_SPI_MAX_XFER_SIZE) + return -EINVAL; + + tx.port = dln2->port; + tx.size = cpu_to_le16(data_len); + tx.attr = attr; + + ret = dln2_transfer(dln2->pdev, DLN2_SPI_READ, &tx, sizeof(tx), + rx, &rx_len); + if (ret < 0) + return ret; + if (rx_len < sizeof(rx->size) + data_len) + return -EPROTO; + if (le16_to_cpu(rx->size) != data_len) + return -EPROTO; + + dln2_spi_copy_from_buf(data, rx->buf, data_len, dln2->bpw); + + return 0; +} + +/* + * Perform one write & read operation. + */ +static int dln2_spi_read_write_one(struct dln2_spi *dln2, const u8 *tx_data, + u8 *rx_data, u16 data_len, u8 attr) +{ + int ret; + struct { + u8 port; + __le16 size; + u8 attr; + u8 buf[DLN2_SPI_MAX_XFER_SIZE]; + } __packed *tx; + struct { + __le16 size; + u8 buf[DLN2_SPI_MAX_XFER_SIZE]; + } __packed *rx; + unsigned tx_len, rx_len; + + BUILD_BUG_ON(sizeof(*tx) > DLN2_SPI_BUF_SIZE || + sizeof(*rx) > DLN2_SPI_BUF_SIZE); + + if (data_len > DLN2_SPI_MAX_XFER_SIZE) + return -EINVAL; + + /* + * Since this is a pseudo full-duplex communication, we're perfectly + * safe to use the same buffer for both tx and rx. When DLN2 sends the + * response back, with the rx data, we don't need the tx buffer anymore. + */ + tx = dln2->buf; + rx = dln2->buf; + + tx->port = dln2->port; + tx->size = cpu_to_le16(data_len); + tx->attr = attr; + + dln2_spi_copy_to_buf(tx->buf, tx_data, data_len, dln2->bpw); + + tx_len = sizeof(*tx) + data_len - DLN2_SPI_MAX_XFER_SIZE; + rx_len = sizeof(*rx); + + ret = dln2_transfer(dln2->pdev, DLN2_SPI_READ_WRITE, tx, tx_len, + rx, &rx_len); + if (ret < 0) + return ret; + if (rx_len < sizeof(rx->size) + data_len) + return -EPROTO; + if (le16_to_cpu(rx->size) != data_len) + return -EPROTO; + + dln2_spi_copy_from_buf(rx_data, rx->buf, data_len, dln2->bpw); + + return 0; +} + +/* + * Read/Write wrapper. It will automatically split an operation into multiple + * single ones due to device buffer constraints. + */ +static int dln2_spi_rdwr(struct dln2_spi *dln2, const u8 *tx_data, + u8 *rx_data, u16 data_len, u8 attr) { + int ret; + u16 len; + u8 temp_attr; + u16 remaining = data_len; + u16 offset; + + do { + if (remaining > DLN2_SPI_MAX_XFER_SIZE) { + len = DLN2_SPI_MAX_XFER_SIZE; + temp_attr = DLN2_SPI_ATTR_LEAVE_SS_LOW; + } else { + len = remaining; + temp_attr = attr; + } + + offset = data_len - remaining; + + if (tx_data && rx_data) { + ret = dln2_spi_read_write_one(dln2, + tx_data + offset, + rx_data + offset, + len, temp_attr); + } else if (tx_data) { + ret = dln2_spi_write_one(dln2, + tx_data + offset, + len, temp_attr); + } else if (rx_data) { + ret = dln2_spi_read_one(dln2, + rx_data + offset, + len, temp_attr); + } else { + return -EINVAL; + } + + if (ret < 0) + return ret; + + remaining -= len; + } while (remaining); + + return 0; +} + +static int dln2_spi_prepare_message(struct spi_master *master, + struct spi_message *message) +{ + int ret; + struct dln2_spi *dln2 = spi_master_get_devdata(master); + struct spi_device *spi = message->spi; + + if (dln2->cs != spi->chip_select) { + ret = dln2_spi_cs_set_one(dln2, spi->chip_select); + if (ret < 0) + return ret; + + dln2->cs = spi->chip_select; + } + + return 0; +} + +static int dln2_spi_transfer_setup(struct dln2_spi *dln2, u32 speed, + u8 bpw, u8 mode) +{ + int ret; + bool bus_setup_change; + + bus_setup_change = dln2->speed != speed || dln2->mode != mode || + dln2->bpw != bpw; + + if (!bus_setup_change) + return 0; + + ret = dln2_spi_enable(dln2, false); + if (ret < 0) + return ret; + + if (dln2->speed != speed) { + ret = dln2_spi_set_speed(dln2, speed); + if (ret < 0) + return ret; + + dln2->speed = speed; + } + + if (dln2->mode != mode) { + ret = dln2_spi_set_mode(dln2, mode & 0x3); + if (ret < 0) + return ret; + + dln2->mode = mode; + } + + if (dln2->bpw != bpw) { + ret = dln2_spi_set_bpw(dln2, bpw); + if (ret < 0) + return ret; + + dln2->bpw = bpw; + } + + return dln2_spi_enable(dln2, true); +} + +static int dln2_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct dln2_spi *dln2 = spi_master_get_devdata(master); + int status; + u8 attr = 0; + + status = dln2_spi_transfer_setup(dln2, xfer->speed_hz, + xfer->bits_per_word, + spi->mode); + if (status < 0) { + dev_err(&dln2->pdev->dev, "Cannot setup transfer\n"); + return status; + } + + if (!xfer->cs_change && !spi_transfer_is_last(master, xfer)) + attr = DLN2_SPI_ATTR_LEAVE_SS_LOW; + + status = dln2_spi_rdwr(dln2, xfer->tx_buf, xfer->rx_buf, + xfer->len, attr); + if (status < 0) + dev_err(&dln2->pdev->dev, "write/read failed!\n"); + + return status; +} + +static int dln2_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct dln2_spi *dln2; + struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev); + struct device *dev = &pdev->dev; + int ret; + + master = spi_alloc_master(&pdev->dev, sizeof(*dln2)); + if (!master) + return -ENOMEM; + + platform_set_drvdata(pdev, master); + + dln2 = spi_master_get_devdata(master); + + dln2->buf = devm_kmalloc(&pdev->dev, DLN2_SPI_BUF_SIZE, GFP_KERNEL); + if (!dln2->buf) { + ret = -ENOMEM; + goto exit_free_master; + } + + dln2->master = master; + dln2->master->dev.of_node = dev->of_node; + dln2->pdev = pdev; + dln2->port = pdata->port; + /* cs/mode can never be 0xff, so the first transfer will set them */ + dln2->cs = 0xff; + dln2->mode = 0xff; + + /* disable SPI module before continuing with the setup */ + ret = dln2_spi_enable(dln2, false); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to disable SPI module\n"); + goto exit_free_master; + } + + ret = dln2_spi_get_cs_num(dln2, &master->num_chipselect); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to get number of CS pins\n"); + goto exit_free_master; + } + + ret = dln2_spi_get_speed_range(dln2, + &master->min_speed_hz, + &master->max_speed_hz); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to read bus min/max freqs\n"); + goto exit_free_master; + } + + ret = dln2_spi_get_supported_frame_sizes(dln2, + &master->bits_per_word_mask); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to read supported frame sizes\n"); + goto exit_free_master; + } + + ret = dln2_spi_cs_enable_all(dln2, true); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to enable CS pins\n"); + goto exit_free_master; + } + + master->bus_num = -1; + master->mode_bits = SPI_CPOL | SPI_CPHA; + master->prepare_message = dln2_spi_prepare_message; + master->transfer_one = dln2_spi_transfer_one; + master->auto_runtime_pm = true; + + /* enable SPI module, we're good to go */ + ret = dln2_spi_enable(dln2, true); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to enable SPI module\n"); + goto exit_free_master; + } + + pm_runtime_set_autosuspend_delay(&pdev->dev, + DLN2_RPM_AUTOSUSPEND_TIMEOUT); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + ret = devm_spi_register_master(&pdev->dev, master); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to register master\n"); + goto exit_register; + } + + return ret; + +exit_register: + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + + if (dln2_spi_enable(dln2, false) < 0) + dev_err(&pdev->dev, "Failed to disable SPI module\n"); +exit_free_master: + spi_master_put(master); + + return ret; +} + +static int dln2_spi_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct dln2_spi *dln2 = spi_master_get_devdata(master); + + pm_runtime_disable(&pdev->dev); + + if (dln2_spi_enable(dln2, false) < 0) + dev_err(&pdev->dev, "Failed to disable SPI module\n"); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int dln2_spi_suspend(struct device *dev) +{ + int ret; + struct spi_master *master = dev_get_drvdata(dev); + struct dln2_spi *dln2 = spi_master_get_devdata(master); + + ret = spi_master_suspend(master); + if (ret < 0) + return ret; + + if (!pm_runtime_suspended(dev)) { + ret = dln2_spi_enable(dln2, false); + if (ret < 0) + return ret; + } + + /* + * USB power may be cut off during sleep. Resetting the following + * parameters will force the board to be set up before first transfer. + */ + dln2->cs = 0xff; + dln2->speed = 0; + dln2->bpw = 0; + dln2->mode = 0xff; + + return 0; +} + +static int dln2_spi_resume(struct device *dev) +{ + int ret; + struct spi_master *master = dev_get_drvdata(dev); + struct dln2_spi *dln2 = spi_master_get_devdata(master); + + if (!pm_runtime_suspended(dev)) { + ret = dln2_spi_cs_enable_all(dln2, true); + if (ret < 0) + return ret; + + ret = dln2_spi_enable(dln2, true); + if (ret < 0) + return ret; + } + + return spi_master_resume(master); +} +#endif /* CONFIG_PM_SLEEP */ + +#ifdef CONFIG_PM +static int dln2_spi_runtime_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct dln2_spi *dln2 = spi_master_get_devdata(master); + + return dln2_spi_enable(dln2, false); +} + +static int dln2_spi_runtime_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct dln2_spi *dln2 = spi_master_get_devdata(master); + + return dln2_spi_enable(dln2, true); +} +#endif /* CONFIG_PM */ + +static const struct dev_pm_ops dln2_spi_pm = { + SET_SYSTEM_SLEEP_PM_OPS(dln2_spi_suspend, dln2_spi_resume) + SET_RUNTIME_PM_OPS(dln2_spi_runtime_suspend, + dln2_spi_runtime_resume, NULL) +}; + +static struct platform_driver spi_dln2_driver = { + .driver = { + .name = "dln2-spi", + .pm = &dln2_spi_pm, + }, + .probe = dln2_spi_probe, + .remove = dln2_spi_remove, +}; +module_platform_driver(spi_dln2_driver); + +MODULE_DESCRIPTION("Driver for the Diolan DLN2 SPI master interface"); +MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:dln2-spi"); |