diff options
| -rw-r--r-- | MAINTAINERS | 7 | ||||
| -rw-r--r-- | drivers/spi/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/spi-virtio.c | 431 | ||||
| -rw-r--r-- | include/uapi/linux/virtio_ids.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/virtio_spi.h | 181 |
6 files changed, 632 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 931e68699ab9..21abd9cf86f9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -26803,6 +26803,13 @@ S: Maintained F: include/uapi/linux/virtio_snd.h F: sound/virtio/* +VIRTIO SPI DRIVER +M: Haixu Cui <quic_haixcui@quicinc.com> +L: virtualization@lists.linux.dev +S: Maintained +F: drivers/spi/spi-virtio.c +F: include/uapi/linux/virtio_spi.h + VIRTUAL BOX GUEST DEVICE DRIVER M: Hans de Goede <hansg@kernel.org> M: Arnd Bergmann <arnd@arndb.de> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 3b864df9b4d6..e8a39e304c7e 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -1235,6 +1235,17 @@ config SPI_UNIPHIER If your SoC supports SCSSI, say Y here. +config SPI_VIRTIO + tristate "Virtio SPI Controller" + depends on SPI_MASTER && VIRTIO + help + If you say yes to this option, support will be included for the virtio + SPI controller driver. The hardware can be emulated by any device model + software according to the virtio protocol. + + This driver can also be built as a module. If so, the module + will be called spi-virtio. + config SPI_XCOMM tristate "Analog Devices AD-FMCOMMS1-EBZ SPI-I2C-bridge driver" depends on I2C diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index eefaeca09745..8ff74a13faaa 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -159,6 +159,7 @@ spi-thunderx-objs := spi-cavium.o spi-cavium-thunderx.o obj-$(CONFIG_SPI_THUNDERX) += spi-thunderx.o obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi-topcliff-pch.o obj-$(CONFIG_SPI_UNIPHIER) += spi-uniphier.o +obj-$(CONFIG_SPI_VIRTIO) += spi-virtio.o obj-$(CONFIG_SPI_XCOMM) += spi-xcomm.o obj-$(CONFIG_SPI_XILINX) += spi-xilinx.o obj-$(CONFIG_SPI_XLP) += spi-xlp.o diff --git a/drivers/spi/spi-virtio.c b/drivers/spi/spi-virtio.c new file mode 100644 index 000000000000..2acb929b2c69 --- /dev/null +++ b/drivers/spi/spi-virtio.c @@ -0,0 +1,431 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SPI bus driver for the Virtio SPI controller + * Copyright (C) 2023 OpenSynergy GmbH + * Copyright (C) 2025 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#include <linux/completion.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/spi/spi.h> +#include <linux/stddef.h> +#include <linux/virtio.h> +#include <linux/virtio_ring.h> +#include <linux/virtio_spi.h> + +#define VIRTIO_SPI_MODE_MASK \ + (SPI_MODE_X_MASK | SPI_CS_HIGH | SPI_LSB_FIRST) + +struct virtio_spi_req { + struct completion completion; + const u8 *tx_buf; + u8 *rx_buf; + struct spi_transfer_head transfer_head ____cacheline_aligned; + struct spi_transfer_result result; +}; + +struct virtio_spi_priv { + /* The virtio device we're associated with */ + struct virtio_device *vdev; + /* Pointer to the virtqueue */ + struct virtqueue *vq; + /* Copy of config space mode_func_supported */ + u32 mode_func_supported; + /* Copy of config space max_freq_hz */ + u32 max_freq_hz; +}; + +static void virtio_spi_msg_done(struct virtqueue *vq) +{ + struct virtio_spi_req *req; + unsigned int len; + + while ((req = virtqueue_get_buf(vq, &len))) + complete(&req->completion); +} + +/* + * virtio_spi_set_delays - Set delay parameters for SPI transfer + * + * This function sets various delay parameters for SPI transfer, + * including delay after CS asserted, timing intervals between + * adjacent words within a transfer, delay before and after CS + * deasserted. It converts these delay parameters to nanoseconds + * using spi_delay_to_ns and stores the results in spi_transfer_head + * structure. + * If the conversion fails, the function logs a warning message and + * returns an error code. + * . . . . . . . . . . + * Delay + A + + B + + C + D + E + F + A + + * . . . . . . . . . . + * ___. . . . . . .___.___. . + * CS# |___.______.____.____.___.___| . |___._____________ + * . . . . . . . . . . + * . . . . . . . . . . + * SCLK__.___.___NNN_____NNN__.___.___.___.___.___.___NNN_______ + * + * NOTE: 1st transfer has two words, the delay between these two words are + * 'B' in the diagram. + * + * A => struct spi_device -> cs_setup + * B => max{struct spi_transfer -> word_delay, struct spi_device -> word_delay} + * Note: spi_device and spi_transfer both have word_delay, Linux + * choose the bigger one, refer to _spi_xfer_word_delay_update function + * C => struct spi_transfer -> delay + * D => struct spi_device -> cs_hold + * E => struct spi_device -> cs_inactive + * F => struct spi_transfer -> cs_change_delay + * + * So the corresponding relationship: + * A <===> cs_setup_ns (after CS asserted) + * B <===> word_delay_ns (delay between adjacent words within a transfer) + * C+D <===> cs_delay_hold_ns (before CS deasserted) + * E+F <===> cs_change_delay_inactive_ns (after CS deasserted, these two + * values are also recommended in the Linux driver to be added up) + */ +static int virtio_spi_set_delays(struct spi_transfer_head *th, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + int cs_setup; + int cs_word_delay_xfer; + int cs_word_delay_spi; + int delay; + int cs_hold; + int cs_inactive; + int cs_change_delay; + + cs_setup = spi_delay_to_ns(&spi->cs_setup, xfer); + if (cs_setup < 0) { + dev_warn(&spi->dev, "Cannot convert cs_setup\n"); + return cs_setup; + } + th->cs_setup_ns = cpu_to_le32(cs_setup); + + cs_word_delay_xfer = spi_delay_to_ns(&xfer->word_delay, xfer); + if (cs_word_delay_xfer < 0) { + dev_warn(&spi->dev, "Cannot convert cs_word_delay_xfer\n"); + return cs_word_delay_xfer; + } + cs_word_delay_spi = spi_delay_to_ns(&spi->word_delay, xfer); + if (cs_word_delay_spi < 0) { + dev_warn(&spi->dev, "Cannot convert cs_word_delay_spi\n"); + return cs_word_delay_spi; + } + + th->word_delay_ns = cpu_to_le32(max(cs_word_delay_spi, cs_word_delay_xfer)); + + delay = spi_delay_to_ns(&xfer->delay, xfer); + if (delay < 0) { + dev_warn(&spi->dev, "Cannot convert delay\n"); + return delay; + } + cs_hold = spi_delay_to_ns(&spi->cs_hold, xfer); + if (cs_hold < 0) { + dev_warn(&spi->dev, "Cannot convert cs_hold\n"); + return cs_hold; + } + th->cs_delay_hold_ns = cpu_to_le32(delay + cs_hold); + + cs_inactive = spi_delay_to_ns(&spi->cs_inactive, xfer); + if (cs_inactive < 0) { + dev_warn(&spi->dev, "Cannot convert cs_inactive\n"); + return cs_inactive; + } + cs_change_delay = spi_delay_to_ns(&xfer->cs_change_delay, xfer); + if (cs_change_delay < 0) { + dev_warn(&spi->dev, "Cannot convert cs_change_delay\n"); + return cs_change_delay; + } + th->cs_change_delay_inactive_ns = + cpu_to_le32(cs_inactive + cs_change_delay); + + return 0; +} + +static int virtio_spi_transfer_one(struct spi_controller *ctrl, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct virtio_spi_priv *priv = spi_controller_get_devdata(ctrl); + struct virtio_spi_req *spi_req __free(kfree) = NULL; + struct spi_transfer_head *th; + struct scatterlist sg_out_head, sg_out_payload; + struct scatterlist sg_in_result, sg_in_payload; + struct scatterlist *sgs[4]; + unsigned int outcnt = 0; + unsigned int incnt = 0; + int ret; + + spi_req = kzalloc(sizeof(*spi_req), GFP_KERNEL); + if (!spi_req) + return -ENOMEM; + + init_completion(&spi_req->completion); + + th = &spi_req->transfer_head; + + /* Fill struct spi_transfer_head */ + th->chip_select_id = spi_get_chipselect(spi, 0); + th->bits_per_word = spi->bits_per_word; + th->cs_change = xfer->cs_change; + th->tx_nbits = xfer->tx_nbits; + th->rx_nbits = xfer->rx_nbits; + th->reserved[0] = 0; + th->reserved[1] = 0; + th->reserved[2] = 0; + + static_assert(VIRTIO_SPI_CPHA == SPI_CPHA, + "VIRTIO_SPI_CPHA must match SPI_CPHA"); + static_assert(VIRTIO_SPI_CPOL == SPI_CPOL, + "VIRTIO_SPI_CPOL must match SPI_CPOL"); + static_assert(VIRTIO_SPI_CS_HIGH == SPI_CS_HIGH, + "VIRTIO_SPI_CS_HIGH must match SPI_CS_HIGH"); + static_assert(VIRTIO_SPI_MODE_LSB_FIRST == SPI_LSB_FIRST, + "VIRTIO_SPI_MODE_LSB_FIRST must match SPI_LSB_FIRST"); + + th->mode = cpu_to_le32(spi->mode & VIRTIO_SPI_MODE_MASK); + if (spi->mode & SPI_LOOP) + th->mode |= cpu_to_le32(VIRTIO_SPI_MODE_LOOP); + + th->freq = cpu_to_le32(xfer->speed_hz); + + ret = virtio_spi_set_delays(th, spi, xfer); + if (ret) + goto msg_done; + + /* Set buffers */ + spi_req->tx_buf = xfer->tx_buf; + spi_req->rx_buf = xfer->rx_buf; + + /* Prepare sending of virtio message */ + init_completion(&spi_req->completion); + + sg_init_one(&sg_out_head, th, sizeof(*th)); + sgs[outcnt] = &sg_out_head; + outcnt++; + + if (spi_req->tx_buf) { + sg_init_one(&sg_out_payload, spi_req->tx_buf, xfer->len); + sgs[outcnt] = &sg_out_payload; + outcnt++; + } + + if (spi_req->rx_buf) { + sg_init_one(&sg_in_payload, spi_req->rx_buf, xfer->len); + sgs[outcnt] = &sg_in_payload; + incnt++; + } + + sg_init_one(&sg_in_result, &spi_req->result, + sizeof(struct spi_transfer_result)); + sgs[outcnt + incnt] = &sg_in_result; + incnt++; + + ret = virtqueue_add_sgs(priv->vq, sgs, outcnt, incnt, spi_req, + GFP_KERNEL); + if (ret) + goto msg_done; + + /* Simple implementation: There can be only one transfer in flight */ + virtqueue_kick(priv->vq); + + wait_for_completion(&spi_req->completion); + + /* Read result from message and translate return code */ + switch (spi_req->result.result) { + case VIRTIO_SPI_TRANS_OK: + break; + case VIRTIO_SPI_PARAM_ERR: + ret = -EINVAL; + break; + case VIRTIO_SPI_TRANS_ERR: + ret = -EIO; + break; + default: + ret = -EIO; + break; + } + +msg_done: + if (ret) + ctrl->cur_msg->status = ret; + + return ret; +} + +static void virtio_spi_read_config(struct virtio_device *vdev) +{ + struct spi_controller *ctrl = dev_get_drvdata(&vdev->dev); + struct virtio_spi_priv *priv = vdev->priv; + u8 cs_max_number; + u8 tx_nbits_supported; + u8 rx_nbits_supported; + + cs_max_number = virtio_cread8(vdev, offsetof(struct virtio_spi_config, + cs_max_number)); + ctrl->num_chipselect = cs_max_number; + + /* Set the mode bits which are understood by this driver */ + priv->mode_func_supported = + virtio_cread32(vdev, offsetof(struct virtio_spi_config, + mode_func_supported)); + ctrl->mode_bits = priv->mode_func_supported & + (VIRTIO_SPI_CS_HIGH | VIRTIO_SPI_MODE_LSB_FIRST); + if (priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_CPHA_1) + ctrl->mode_bits |= VIRTIO_SPI_CPHA; + if (priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_CPOL_1) + ctrl->mode_bits |= VIRTIO_SPI_CPOL; + if (priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_LSB_FIRST) + ctrl->mode_bits |= SPI_LSB_FIRST; + if (priv->mode_func_supported & VIRTIO_SPI_MF_SUPPORT_LOOPBACK) + ctrl->mode_bits |= SPI_LOOP; + tx_nbits_supported = + virtio_cread8(vdev, offsetof(struct virtio_spi_config, + tx_nbits_supported)); + if (tx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_DUAL) + ctrl->mode_bits |= SPI_TX_DUAL; + if (tx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_QUAD) + ctrl->mode_bits |= SPI_TX_QUAD; + if (tx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_OCTAL) + ctrl->mode_bits |= SPI_TX_OCTAL; + rx_nbits_supported = + virtio_cread8(vdev, offsetof(struct virtio_spi_config, + rx_nbits_supported)); + if (rx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_DUAL) + ctrl->mode_bits |= SPI_RX_DUAL; + if (rx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_QUAD) + ctrl->mode_bits |= SPI_RX_QUAD; + if (rx_nbits_supported & VIRTIO_SPI_RX_TX_SUPPORT_OCTAL) + ctrl->mode_bits |= SPI_RX_OCTAL; + + ctrl->bits_per_word_mask = + virtio_cread32(vdev, offsetof(struct virtio_spi_config, + bits_per_word_mask)); + + priv->max_freq_hz = + virtio_cread32(vdev, offsetof(struct virtio_spi_config, + max_freq_hz)); +} + +static int virtio_spi_find_vqs(struct virtio_spi_priv *priv) +{ + struct virtqueue *vq; + + vq = virtio_find_single_vq(priv->vdev, virtio_spi_msg_done, "spi-rq"); + if (IS_ERR(vq)) + return PTR_ERR(vq); + priv->vq = vq; + return 0; +} + +/* Function must not be called before virtio_spi_find_vqs() has been run */ +static void virtio_spi_del_vq(void *data) +{ + struct virtio_device *vdev = data; + + virtio_reset_device(vdev); + vdev->config->del_vqs(vdev); +} + +static int virtio_spi_probe(struct virtio_device *vdev) +{ + struct virtio_spi_priv *priv; + struct spi_controller *ctrl; + int ret; + + ctrl = devm_spi_alloc_host(&vdev->dev, sizeof(*priv)); + if (!ctrl) + return -ENOMEM; + + priv = spi_controller_get_devdata(ctrl); + priv->vdev = vdev; + vdev->priv = priv; + + device_set_node(&ctrl->dev, dev_fwnode(&vdev->dev)); + + dev_set_drvdata(&vdev->dev, ctrl); + + virtio_spi_read_config(vdev); + + ctrl->transfer_one = virtio_spi_transfer_one; + + ret = virtio_spi_find_vqs(priv); + if (ret) + return dev_err_probe(&vdev->dev, ret, "Cannot setup virtqueues\n"); + + /* Register cleanup for virtqueues using devm */ + ret = devm_add_action_or_reset(&vdev->dev, virtio_spi_del_vq, vdev); + if (ret) + return dev_err_probe(&vdev->dev, ret, "Cannot register virtqueue cleanup\n"); + + /* Use devm version to register controller */ + ret = devm_spi_register_controller(&vdev->dev, ctrl); + if (ret) + return dev_err_probe(&vdev->dev, ret, "Cannot register controller\n"); + + return 0; +} + +static int virtio_spi_freeze(struct device *dev) +{ + struct spi_controller *ctrl = dev_get_drvdata(dev); + struct virtio_device *vdev = dev_to_virtio(dev); + int ret; + + ret = spi_controller_suspend(ctrl); + if (ret) { + dev_warn(dev, "cannot suspend controller (%d)\n", ret); + return ret; + } + + virtio_spi_del_vq(vdev); + return 0; +} + +static int virtio_spi_restore(struct device *dev) +{ + struct spi_controller *ctrl = dev_get_drvdata(dev); + struct virtio_device *vdev = dev_to_virtio(dev); + int ret; + + ret = virtio_spi_find_vqs(vdev->priv); + if (ret) { + dev_err(dev, "problem starting vqueue (%d)\n", ret); + return ret; + } + + ret = spi_controller_resume(ctrl); + if (ret) + dev_err(dev, "problem resuming controller (%d)\n", ret); + + return ret; +} + +static struct virtio_device_id virtio_spi_id_table[] = { + { VIRTIO_ID_SPI, VIRTIO_DEV_ANY_ID }, + {} +}; +MODULE_DEVICE_TABLE(virtio, virtio_spi_id_table); + +static const struct dev_pm_ops virtio_spi_pm_ops = { + .freeze = pm_sleep_ptr(virtio_spi_freeze), + .restore = pm_sleep_ptr(virtio_spi_restore), +}; + +static struct virtio_driver virtio_spi_driver = { + .driver = { + .name = KBUILD_MODNAME, + .pm = &virtio_spi_pm_ops, + }, + .id_table = virtio_spi_id_table, + .probe = virtio_spi_probe, +}; +module_virtio_driver(virtio_spi_driver); + +MODULE_AUTHOR("OpenSynergy GmbH"); +MODULE_AUTHOR("Haixu Cui <quic_haixcui@quicinc.com>"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Virtio SPI bus driver"); diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h index 7aa2eb766205..6c12db16faa3 100644 --- a/include/uapi/linux/virtio_ids.h +++ b/include/uapi/linux/virtio_ids.h @@ -68,6 +68,7 @@ #define VIRTIO_ID_AUDIO_POLICY 39 /* virtio audio policy */ #define VIRTIO_ID_BT 40 /* virtio bluetooth */ #define VIRTIO_ID_GPIO 41 /* virtio gpio */ +#define VIRTIO_ID_SPI 45 /* virtio spi */ /* * Virtio Transitional IDs diff --git a/include/uapi/linux/virtio_spi.h b/include/uapi/linux/virtio_spi.h new file mode 100644 index 000000000000..8ab3c970cdd3 --- /dev/null +++ b/include/uapi/linux/virtio_spi.h @@ -0,0 +1,181 @@ +/* SPDX-License-Identifier: BSD-3-Clause */ +/* + * Copyright (C) 2023 OpenSynergy GmbH + * Copyright (C) 2025 Qualcomm Innovation Center, Inc. All rights reserved. + */ +#ifndef _LINUX_VIRTIO_VIRTIO_SPI_H +#define _LINUX_VIRTIO_VIRTIO_SPI_H + +#include <linux/types.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_types.h> + +/* Sample data on trailing clock edge */ +#define VIRTIO_SPI_CPHA _BITUL(0) +/* Clock is high when IDLE */ +#define VIRTIO_SPI_CPOL _BITUL(1) +/* Chip Select is active high */ +#define VIRTIO_SPI_CS_HIGH _BITUL(2) +/* Transmit LSB first */ +#define VIRTIO_SPI_MODE_LSB_FIRST _BITUL(3) +/* Loopback mode */ +#define VIRTIO_SPI_MODE_LOOP _BITUL(4) + +/** + * struct virtio_spi_config - All config fields are read-only for the + * Virtio SPI driver + * @cs_max_number: maximum number of chipselect the host SPI controller + * supports. + * @cs_change_supported: indicates if the host SPI controller supports to toggle + * chipselect after each transfer in one message: + * 0: unsupported, chipselect will be kept in active state throughout the + * message transaction; + * 1: supported. + * Note: Message here contains a sequence of SPI transfers. + * @tx_nbits_supported: indicates the supported number of bit for writing: + * bit 0: DUAL (2-bit transfer), 1 for supported + * bit 1: QUAD (4-bit transfer), 1 for supported + * bit 2: OCTAL (8-bit transfer), 1 for supported + * other bits are reserved as 0, 1-bit transfer is always supported. + * @rx_nbits_supported: indicates the supported number of bit for reading: + * bit 0: DUAL (2-bit transfer), 1 for supported + * bit 1: QUAD (4-bit transfer), 1 for supported + * bit 2: OCTAL (8-bit transfer), 1 for supported + * other bits are reserved as 0, 1-bit transfer is always supported. + * @bits_per_word_mask: mask indicating which values of bits_per_word are + * supported. If not set, no limitation for bits_per_word. + * @mode_func_supported: indicates the following features are supported or not: + * bit 0-1: CPHA feature + * 0b00: invalid, should support as least one CPHA setting + * 0b01: supports CPHA=0 only + * 0b10: supports CPHA=1 only + * 0b11: supports CPHA=0 and CPHA=1. + * bit 2-3: CPOL feature + * 0b00: invalid, should support as least one CPOL setting + * 0b01: supports CPOL=0 only + * 0b10: supports CPOL=1 only + * 0b11: supports CPOL=0 and CPOL=1. + * bit 4: chipselect active high feature, 0 for unsupported and 1 for + * supported, chipselect active low is supported by default. + * bit 5: LSB first feature, 0 for unsupported and 1 for supported, + * MSB first is supported by default. + * bit 6: loopback mode feature, 0 for unsupported and 1 for supported, + * normal mode is supported by default. + * @max_freq_hz: the maximum clock rate supported in Hz unit, 0 means no + * limitation for transfer speed. + * @max_word_delay_ns: the maximum word delay supported, in nanoseconds. + * A value of 0 indicates that word delay is unsupported. + * Each transfer may consist of a sequence of words. + * @max_cs_setup_ns: the maximum delay supported after chipselect is asserted, + * in ns unit, 0 means delay is not supported to introduce after chipselect is + * asserted. + * @max_cs_hold_ns: the maximum delay supported before chipselect is deasserted, + * in ns unit, 0 means delay is not supported to introduce before chipselect + * is deasserted. + * @max_cs_incative_ns: maximum delay supported after chipselect is deasserted, + * in ns unit, 0 means delay is not supported to introduce after chipselect is + * deasserted. + */ +struct virtio_spi_config { + __u8 cs_max_number; + __u8 cs_change_supported; +#define VIRTIO_SPI_RX_TX_SUPPORT_DUAL _BITUL(0) +#define VIRTIO_SPI_RX_TX_SUPPORT_QUAD _BITUL(1) +#define VIRTIO_SPI_RX_TX_SUPPORT_OCTAL _BITUL(2) + __u8 tx_nbits_supported; + __u8 rx_nbits_supported; + __le32 bits_per_word_mask; +#define VIRTIO_SPI_MF_SUPPORT_CPHA_0 _BITUL(0) +#define VIRTIO_SPI_MF_SUPPORT_CPHA_1 _BITUL(1) +#define VIRTIO_SPI_MF_SUPPORT_CPOL_0 _BITUL(2) +#define VIRTIO_SPI_MF_SUPPORT_CPOL_1 _BITUL(3) +#define VIRTIO_SPI_MF_SUPPORT_CS_HIGH _BITUL(4) +#define VIRTIO_SPI_MF_SUPPORT_LSB_FIRST _BITUL(5) +#define VIRTIO_SPI_MF_SUPPORT_LOOPBACK _BITUL(6) + __le32 mode_func_supported; + __le32 max_freq_hz; + __le32 max_word_delay_ns; + __le32 max_cs_setup_ns; + __le32 max_cs_hold_ns; + __le32 max_cs_inactive_ns; +}; + +/** + * struct spi_transfer_head - virtio SPI transfer descriptor + * @chip_select_id: chipselect index the SPI transfer used. + * @bits_per_word: the number of bits in each SPI transfer word. + * @cs_change: whether to deselect device after finishing this transfer + * before starting the next transfer, 0 means cs keep asserted and + * 1 means cs deasserted then asserted again. + * @tx_nbits: bus width for write transfer. + * 0,1: bus width is 1, also known as SINGLE + * 2 : bus width is 2, also known as DUAL + * 4 : bus width is 4, also known as QUAD + * 8 : bus width is 8, also known as OCTAL + * other values are invalid. + * @rx_nbits: bus width for read transfer. + * 0,1: bus width is 1, also known as SINGLE + * 2 : bus width is 2, also known as DUAL + * 4 : bus width is 4, also known as QUAD + * 8 : bus width is 8, also known as OCTAL + * other values are invalid. + * @reserved: for future use. + * @mode: SPI transfer mode. + * bit 0: CPHA, determines the timing (i.e. phase) of the data + * bits relative to the clock pulses.For CPHA=0, the + * "out" side changes the data on the trailing edge of the + * preceding clock cycle, while the "in" side captures the data + * on (or shortly after) the leading edge of the clock cycle. + * For CPHA=1, the "out" side changes the data on the leading + * edge of the current clock cycle, while the "in" side + * captures the data on (or shortly after) the trailing edge of + * the clock cycle. + * bit 1: CPOL, determines the polarity of the clock. CPOL=0 is a + * clock which idles at 0, and each cycle consists of a pulse + * of 1. CPOL=1 is a clock which idles at 1, and each cycle + * consists of a pulse of 0. + * bit 2: CS_HIGH, if 1, chip select active high, else active low. + * bit 3: LSB_FIRST, determines per-word bits-on-wire, if 0, MSB + * first, else LSB first. + * bit 4: LOOP, loopback mode. + * @freq: the transfer speed in Hz. + * @word_delay_ns: delay to be inserted between consecutive words of a + * transfer, in ns unit. + * @cs_setup_ns: delay to be introduced after CS is asserted, in ns + * unit. + * @cs_delay_hold_ns: delay to be introduced before CS is deasserted + * for each transfer, in ns unit. + * @cs_change_delay_inactive_ns: delay to be introduced after CS is + * deasserted and before next asserted, in ns unit. + */ +struct spi_transfer_head { + __u8 chip_select_id; + __u8 bits_per_word; + __u8 cs_change; + __u8 tx_nbits; + __u8 rx_nbits; + __u8 reserved[3]; + __le32 mode; + __le32 freq; + __le32 word_delay_ns; + __le32 cs_setup_ns; + __le32 cs_delay_hold_ns; + __le32 cs_change_delay_inactive_ns; +}; + +/** + * struct spi_transfer_result - virtio SPI transfer result + * @result: Transfer result code. + * VIRTIO_SPI_TRANS_OK: Transfer successful. + * VIRTIO_SPI_PARAM_ERR: Parameter error. + * VIRTIO_SPI_TRANS_ERR: Transfer error. + */ +struct spi_transfer_result { +#define VIRTIO_SPI_TRANS_OK 0 +#define VIRTIO_SPI_PARAM_ERR 1 +#define VIRTIO_SPI_TRANS_ERR 2 + __u8 result; +}; + +#endif /* #ifndef _LINUX_VIRTIO_VIRTIO_SPI_H */ |