#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)
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,
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[] __counted_by(len);
} __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_host(&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;
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 },
{ }
};
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");
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");
