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// SPDX-License-Identifier: GPL-2.0-only
/*
* Source for:
* Cypress TrueTouch(TM) Standard Product (TTSP) SPI touchscreen driver.
* For use with Cypress Txx3xx parts.
* Supported parts include:
* CY8CTST341
* CY8CTMA340
*
* Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
* Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
* Copyright (C) 2013 Cypress Semiconductor
*
* Contact Cypress Semiconductor at www.cypress.com <ttdrivers@cypress.com>
*/
#include "cyttsp_core.h"
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/spi/spi.h>
#define CY_SPI_WR_OP 0x00 /* r/~w */
#define CY_SPI_RD_OP 0x01
#define CY_SPI_CMD_BYTES 4
#define CY_SPI_SYNC_BYTE 2
#define CY_SPI_SYNC_ACK1 0x62 /* from protocol v.2 */
#define CY_SPI_SYNC_ACK2 0x9D /* from protocol v.2 */
#define CY_SPI_DATA_SIZE 128
#define CY_SPI_DATA_BUF_SIZE (CY_SPI_CMD_BYTES + CY_SPI_DATA_SIZE)
#define CY_SPI_BITS_PER_WORD 8
static int cyttsp_spi_xfer(struct device *dev, u8 *xfer_buf,
u8 op, u16 reg, u8 *buf, int length)
{
struct spi_device *spi = to_spi_device(dev);
struct spi_message msg;
struct spi_transfer xfer[2];
u8 *wr_buf = &xfer_buf[0];
u8 *rd_buf = &xfer_buf[CY_SPI_DATA_BUF_SIZE];
int retval;
int i;
if (length > CY_SPI_DATA_SIZE) {
dev_err(dev, "%s: length %d is too big.\n",
__func__, length);
return -EINVAL;
}
memset(wr_buf, 0, CY_SPI_DATA_BUF_SIZE);
memset(rd_buf, 0, CY_SPI_DATA_BUF_SIZE);
wr_buf[0] = 0x00; /* header byte 0 */
wr_buf[1] = 0xFF; /* header byte 1 */
wr_buf[2] = reg; /* reg index */
wr_buf[3] = op; /* r/~w */
if (op == CY_SPI_WR_OP)
memcpy(wr_buf + CY_SPI_CMD_BYTES, buf, length);
memset(xfer, 0, sizeof(xfer));
spi_message_init(&msg);
/*
We set both TX and RX buffers because Cypress TTSP
requires full duplex operation.
*/
xfer[0].tx_buf = wr_buf;
xfer[0].rx_buf = rd_buf;
switch (op) {
case CY_SPI_WR_OP:
xfer[0].len = length + CY_SPI_CMD_BYTES;
spi_message_add_tail(&xfer[0], &msg);
break;
case CY_SPI_RD_OP:
xfer[0].len = CY_SPI_CMD_BYTES;
spi_message_add_tail(&xfer[0], &msg);
xfer[1].rx_buf = buf;
xfer[1].len = length;
spi_message_add_tail(&xfer[1], &msg);
break;
default:
dev_err(dev, "%s: bad operation code=%d\n", __func__, op);
return -EINVAL;
}
retval = spi_sync(spi, &msg);
if (retval < 0) {
dev_dbg(dev, "%s: spi_sync() error %d, len=%d, op=%d\n",
__func__, retval, xfer[1].len, op);
/*
* do not return here since was a bad ACK sequence
* let the following ACK check handle any errors and
* allow silent retries
*/
}
if (rd_buf[CY_SPI_SYNC_BYTE] != CY_SPI_SYNC_ACK1 ||
rd_buf[CY_SPI_SYNC_BYTE + 1] != CY_SPI_SYNC_ACK2) {
dev_dbg(dev, "%s: operation %d failed\n", __func__, op);
for (i = 0; i < CY_SPI_CMD_BYTES; i++)
dev_dbg(dev, "%s: test rd_buf[%d]:0x%02x\n",
__func__, i, rd_buf[i]);
for (i = 0; i < length; i++)
dev_dbg(dev, "%s: test buf[%d]:0x%02x\n",
__func__, i, buf[i]);
return -EIO;
}
return 0;
}
static int cyttsp_spi_read_block_data(struct device *dev, u8 *xfer_buf,
u16 addr, u8 length, void *data)
{
return cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_RD_OP, addr, data,
length);
}
static int cyttsp_spi_write_block_data(struct device *dev, u8 *xfer_buf,
u16 addr, u8 length, const void *data)
{
return cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_WR_OP, addr, (void *)data,
length);
}
static const struct cyttsp_bus_ops cyttsp_spi_bus_ops = {
.bustype = BUS_SPI,
.write = cyttsp_spi_write_block_data,
.read = cyttsp_spi_read_block_data,
};
static int cyttsp_spi_probe(struct spi_device *spi)
{
struct cyttsp *ts;
int error;
/* Set up SPI*/
spi->bits_per_word = CY_SPI_BITS_PER_WORD;
spi->mode = SPI_MODE_0;
error = spi_setup(spi);
if (error < 0) {
dev_err(&spi->dev, "%s: SPI setup error %d\n",
__func__, error);
return error;
}
ts = cyttsp_probe(&cyttsp_spi_bus_ops, &spi->dev, spi->irq,
CY_SPI_DATA_BUF_SIZE * 2);
if (IS_ERR(ts))
return PTR_ERR(ts);
spi_set_drvdata(spi, ts);
return 0;
}
static struct spi_driver cyttsp_spi_driver = {
.driver = {
.name = CY_SPI_NAME,
.pm = &cyttsp_pm_ops,
},
.probe = cyttsp_spi_probe,
};
module_spi_driver(cyttsp_spi_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP) SPI driver");
MODULE_AUTHOR("Cypress");
MODULE_ALIAS("spi:cyttsp");
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