Re: [PATCH v17 3/4] spi: Add support for Intel LJCA USB SPI driver

[Hans de Goede <hdegoede@redhat.com>]

Hi Wentong,

On 9/14/23 14:45, Wentong Wu wrote:
> Implements the SPI function of Intel USB-I2C/GPIO/SPI adapter device
> named "La Jolla Cove Adapter" (LJCA). It communicate with LJCA SPI
> module with specific protocol through interfaces exported by LJCA USB
> driver.
> 
> Signed-off-by: Wentong Wu <wentong.wu@intel.com>
> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
> Tested-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/spi/Kconfig    |  11 ++
>  drivers/spi/Makefile   |   1 +
>  drivers/spi/spi-ljca.c | 297 +++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 309 insertions(+)
>  create mode 100644 drivers/spi/spi-ljca.c
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 8962b25..ad18864 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -583,6 +583,17 @@ config SPI_FSL_ESPI
>  	  From MPC8536, 85xx platform uses the controller, and all P10xx,
>  	  P20xx, P30xx,P40xx, P50xx uses this controller.
>  
> +config SPI_LJCA
> +	tristate "Intel La Jolla Cove Adapter SPI support"
> +	depends on USB_LJCA
> +	default USB_LJCA
> +	help
> +	  Select this option to enable SPI driver for the Intel
> +	  La Jolla Cove Adapter (LJCA) board.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called spi-ljca.
> +
>  config SPI_MESON_SPICC
>  	tristate "Amlogic Meson SPICC controller"
>  	depends on COMMON_CLK
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index 080c2c1..0847962 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -70,6 +70,7 @@ obj-$(CONFIG_SPI_INTEL_PCI)		+= spi-intel-pci.o
>  obj-$(CONFIG_SPI_INTEL_PLATFORM)	+= spi-intel-platform.o
>  obj-$(CONFIG_SPI_LANTIQ_SSC)		+= spi-lantiq-ssc.o
>  obj-$(CONFIG_SPI_JCORE)			+= spi-jcore.o
> +obj-$(CONFIG_SPI_LJCA)			+= spi-ljca.o
>  obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
>  obj-$(CONFIG_SPI_LP8841_RTC)		+= spi-lp8841-rtc.o
>  obj-$(CONFIG_SPI_MESON_SPICC)		+= spi-meson-spicc.o

I don't know what you are using as a base commit for these
patches, but this does not apply cleanly on top of v6.6-rc1.

For the next version of these patches please rebases this on top
of v6.6-rc1; or on Linus' master branch.

Regards,

Hans




> diff --git a/drivers/spi/spi-ljca.c b/drivers/spi/spi-ljca.c
> new file mode 100644
> index 0000000..6b6d000d
> --- /dev/null
> +++ b/drivers/spi/spi-ljca.c
> @@ -0,0 +1,297 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Intel La Jolla Cove Adapter USB-SPI driver
> + *
> + * Copyright (c) 2023, Intel Corporation.
> + */
> +
> +#include <linux/auxiliary_bus.h>
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/dev_printk.h>
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +#include <linux/usb/ljca.h>
> +
> +#define LJCA_SPI_BUS_MAX_HZ		48000000
> +
> +#define LJCA_SPI_BUF_SIZE		60u
> +#define LJCA_SPI_MAX_XFER_SIZE		\
> +	(LJCA_SPI_BUF_SIZE - sizeof(struct ljca_spi_xfer_packet))
> +
> +#define LJCA_SPI_CLK_MODE_POLARITY	BIT(0)
> +#define LJCA_SPI_CLK_MODE_PHASE		BIT(1)
> +
> +#define LJCA_SPI_XFER_INDICATOR_ID	GENMASK(5, 0)
> +#define LJCA_SPI_XFER_INDICATOR_CMPL	BIT(6)
> +#define LJCA_SPI_XFER_INDICATOR_INDEX	BIT(7)
> +
> +/* SPI commands */
> +enum ljca_spi_cmd {
> +	LJCA_SPI_INIT = 1,
> +	LJCA_SPI_READ,
> +	LJCA_SPI_WRITE,
> +	LJCA_SPI_WRITEREAD,
> +	LJCA_SPI_DEINIT,
> +};
> +
> +enum {
> +	LJCA_SPI_BUS_SPEED_24M,
> +	LJCA_SPI_BUS_SPEED_12M,
> +	LJCA_SPI_BUS_SPEED_8M,
> +	LJCA_SPI_BUS_SPEED_6M,
> +	LJCA_SPI_BUS_SPEED_4_8M, /*4.8MHz*/
> +	LJCA_SPI_BUS_SPEED_MIN = LJCA_SPI_BUS_SPEED_4_8M,
> +};
> +
> +enum {
> +	LJCA_SPI_CLOCK_LOW_POLARITY,
> +	LJCA_SPI_CLOCK_HIGH_POLARITY,
> +};
> +
> +enum {
> +	LJCA_SPI_CLOCK_FIRST_PHASE,
> +	LJCA_SPI_CLOCK_SECOND_PHASE,
> +};
> +
> +struct ljca_spi_init_packet {
> +	u8 index;
> +	u8 speed;
> +	u8 mode;
> +} __packed;
> +
> +struct ljca_spi_xfer_packet {
> +	u8 indicator;
> +	u8 len;
> +	u8 data[];
> +} __packed;
> +
> +struct ljca_spi_dev {
> +	struct ljca_client *ljca;
> +	struct spi_controller *controller;
> +	struct ljca_spi_info *spi_info;
> +	u8 speed;
> +	u8 mode;
> +
> +	u8 obuf[LJCA_SPI_BUF_SIZE];
> +	u8 ibuf[LJCA_SPI_BUF_SIZE];
> +};
> +
> +static int ljca_spi_read_write(struct ljca_spi_dev *ljca_spi, const u8 *w_data,
> +			       u8 *r_data, int len, int id, int complete,
> +			       int cmd)
> +{
> +	struct ljca_spi_xfer_packet *w_packet =
> +			(struct ljca_spi_xfer_packet *)ljca_spi->obuf;
> +	struct ljca_spi_xfer_packet *r_packet =
> +			(struct ljca_spi_xfer_packet *)ljca_spi->ibuf;
> +	int ret;
> +
> +	w_packet->indicator = FIELD_PREP(LJCA_SPI_XFER_INDICATOR_ID, id) |
> +			      FIELD_PREP(LJCA_SPI_XFER_INDICATOR_CMPL, complete) |
> +			      FIELD_PREP(LJCA_SPI_XFER_INDICATOR_INDEX,
> +					 ljca_spi->spi_info->id);
> +
> +	if (cmd == LJCA_SPI_READ) {
> +		w_packet->len = sizeof(u16);
> +		*(__le16 *)&w_packet->data[0] = cpu_to_le16(len);
> +	} else {
> +		w_packet->len = len;
> +		memcpy(w_packet->data, w_data, len);
> +	}
> +
> +	ret = ljca_transfer(ljca_spi->ljca, cmd, (u8 *)w_packet,
> +			    struct_size(w_packet, data, w_packet->len),
> +			    (u8 *)r_packet, LJCA_SPI_BUF_SIZE);
> +	if (ret < 0)
> +		return ret;
> +	else if (ret < sizeof(*r_packet) || r_packet->len <= 0)
> +		return -EIO;
> +
> +	if (r_data)
> +		memcpy(r_data, r_packet->data, r_packet->len);
> +
> +	return 0;
> +}
> +
> +static int ljca_spi_init(struct ljca_spi_dev *ljca_spi, u8 div, u8 mode)
> +{
> +	struct ljca_spi_init_packet w_packet = {};
> +	int ret;
> +
> +	if (ljca_spi->mode == mode && ljca_spi->speed == div)
> +		return 0;
> +
> +	w_packet.index = ljca_spi->spi_info->id;
> +	w_packet.speed = div;
> +	w_packet.mode = FIELD_PREP(LJCA_SPI_CLK_MODE_POLARITY,
> +				   (mode & SPI_CPOL) ? LJCA_SPI_CLOCK_HIGH_POLARITY :
> +						       LJCA_SPI_CLOCK_LOW_POLARITY) |
> +			FIELD_PREP(LJCA_SPI_CLK_MODE_PHASE,
> +				   (mode & SPI_CPHA) ? LJCA_SPI_CLOCK_SECOND_PHASE :
> +						       LJCA_SPI_CLOCK_FIRST_PHASE);
> +
> +	ret = ljca_transfer(ljca_spi->ljca, LJCA_SPI_INIT, (u8 *)&w_packet,
> +			    sizeof(w_packet), NULL, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	ljca_spi->mode = mode;
> +	ljca_spi->speed = div;
> +
> +	return 0;
> +}
> +
> +static int ljca_spi_deinit(struct ljca_spi_dev *ljca_spi)
> +{
> +	struct ljca_spi_init_packet w_packet = {};
> +	int ret;
> +
> +	w_packet.index = ljca_spi->spi_info->id;
> +
> +	ret = ljca_transfer(ljca_spi->ljca, LJCA_SPI_DEINIT, (u8 *)&w_packet,
> +			    sizeof(w_packet), NULL, 0);
> +
> +	return ret < 0 ? ret : 0;
> +}
> +
> +static inline int ljca_spi_transfer(struct ljca_spi_dev *ljca_spi,
> +				    const u8 *tx_data, u8 *rx_data, u16 len)
> +{
> +	int complete, cur_len;
> +	int remaining = len;
> +	int cmd, ret, i;
> +	int offset = 0;
> +
> +	if (tx_data && rx_data)
> +		cmd = LJCA_SPI_WRITEREAD;
> +	else if (tx_data)
> +		cmd = LJCA_SPI_WRITE;
> +	else if (rx_data)
> +		cmd = LJCA_SPI_READ;
> +	else
> +		return -EINVAL;
> +
> +	for (i = 0; remaining > 0; i++) {
> +		cur_len = min_t(unsigned int, remaining, LJCA_SPI_MAX_XFER_SIZE);
> +		complete = (cur_len == remaining);
> +
> +		ret = ljca_spi_read_write(ljca_spi,
> +					  tx_data ? tx_data + offset : NULL,
> +					  rx_data ? rx_data + offset : NULL,
> +					  cur_len, i, complete, cmd);
> +		if (ret)
> +			return ret;
> +
> +		offset += cur_len;
> +		remaining -= cur_len;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ljca_spi_transfer_one(struct spi_controller *controller,
> +				 struct spi_device *spi,
> +				 struct spi_transfer *xfer)
> +{
> +	u8 div = DIV_ROUND_UP(controller->max_speed_hz, xfer->speed_hz) / 2 - 1;
> +	struct ljca_spi_dev *ljca_spi = spi_controller_get_devdata(controller);
> +	int ret;
> +
> +	div = min_t(u8, LJCA_SPI_BUS_SPEED_MIN, div);
> +
> +	ret = ljca_spi_init(ljca_spi, div, spi->mode);
> +	if (ret) {
> +		dev_err(&ljca_spi->ljca->auxdev.dev,
> +			"cannot initialize transfer ret %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = ljca_spi_transfer(ljca_spi, xfer->tx_buf, xfer->rx_buf, xfer->len);
> +	if (ret)
> +		dev_err(&ljca_spi->ljca->auxdev.dev,
> +			"transfer failed len: %d\n", xfer->len);
> +
> +	return ret;
> +}
> +
> +static int ljca_spi_probe(struct auxiliary_device *auxdev,
> +			  const struct auxiliary_device_id *aux_dev_id)
> +{
> +	struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
> +	struct spi_controller *controller;
> +	struct ljca_spi_dev *ljca_spi;
> +	int ret;
> +
> +	controller = devm_spi_alloc_master(&auxdev->dev, sizeof(*ljca_spi));
> +	if (!controller)
> +		return -ENOMEM;
> +
> +	ljca_spi = spi_controller_get_devdata(controller);
> +	ljca_spi->ljca = ljca;
> +	ljca_spi->spi_info = dev_get_platdata(&auxdev->dev);
> +	ljca_spi->controller = controller;
> +
> +	controller->bus_num = -1;
> +	controller->mode_bits = SPI_CPHA | SPI_CPOL;
> +	controller->transfer_one = ljca_spi_transfer_one;
> +	controller->auto_runtime_pm = false;
> +	controller->max_speed_hz = LJCA_SPI_BUS_MAX_HZ;
> +
> +	device_set_node(&ljca_spi->controller->dev, dev_fwnode(&auxdev->dev));
> +	auxiliary_set_drvdata(auxdev, controller);
> +
> +	ret = spi_register_controller(controller);
> +	if (ret)
> +		dev_err(&auxdev->dev, "Failed to register controller\n");
> +
> +	return ret;
> +}
> +
> +static void ljca_spi_dev_remove(struct auxiliary_device *auxdev)
> +{
> +	struct spi_controller *controller = auxiliary_get_drvdata(auxdev);
> +	struct ljca_spi_dev *ljca_spi = spi_controller_get_devdata(controller);
> +
> +	spi_unregister_controller(controller);
> +	ljca_spi_deinit(ljca_spi);
> +}
> +
> +static int ljca_spi_dev_suspend(struct device *dev)
> +{
> +	struct spi_controller *controller = dev_get_drvdata(dev);
> +
> +	return spi_controller_suspend(controller);
> +}
> +
> +static int ljca_spi_dev_resume(struct device *dev)
> +{
> +	struct spi_controller *controller = dev_get_drvdata(dev);
> +
> +	return spi_controller_resume(controller);
> +}
> +
> +static const struct dev_pm_ops ljca_spi_pm = {
> +	SYSTEM_SLEEP_PM_OPS(ljca_spi_dev_suspend, ljca_spi_dev_resume)
> +};
> +
> +static const struct auxiliary_device_id ljca_spi_id_table[] = {
> +	{ "usb_ljca.ljca-spi", 0 },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(auxiliary, ljca_spi_id_table);
> +
> +static struct auxiliary_driver ljca_spi_driver = {
> +	.driver.pm	= &ljca_spi_pm,
> +	.probe		= ljca_spi_probe,
> +	.remove		= ljca_spi_dev_remove,
> +	.id_table	= ljca_spi_id_table,
> +};
> +module_auxiliary_driver(ljca_spi_driver);
> +
> +MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
> +MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
> +MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
> +MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-SPI driver");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS(LJCA);