linux/drivers/input/touchscreen/cyttsp4_spi.c
Thomas Gleixner 97fb5e8d9b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 and
  only version 2 as published by the free software foundation this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 294 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.825281744@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00

190 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Source for:
* Cypress TrueTouch(TM) Standard Product (TTSP) SPI touchscreen driver.
* For use with Cypress Txx4xx parts.
* Supported parts include:
* TMA4XX
* TMA1036
*
* 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 "cyttsp4_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_BITS_PER_WORD 8
#define CY_SPI_A8_BIT 0x02
#define CY_SPI_WR_HEADER_BYTES 2
#define CY_SPI_RD_HEADER_BYTES 1
#define CY_SPI_CMD_BYTES 2
#define CY_SPI_SYNC_BYTE 0
#define CY_SPI_SYNC_ACK 0x62 /* from TRM *A protocol */
#define CY_SPI_DATA_SIZE (2 * 256)
#define CY_SPI_DATA_BUF_SIZE (CY_SPI_CMD_BYTES + CY_SPI_DATA_SIZE)
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[CY_SPI_CMD_BYTES];
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_CMD_BYTES);
wr_buf[0] = op + (((reg >> 8) & 0x1) ? CY_SPI_A8_BIT : 0);
if (op == CY_SPI_WR_OP) {
wr_buf[1] = reg & 0xFF;
if (length > 0)
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_RD_HEADER_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_ACK) {
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)
{
int rc;
rc = cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_WR_OP, addr, NULL, 0);
if (rc)
return rc;
else
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 cyttsp4_bus_ops cyttsp_spi_bus_ops = {
.bustype = BUS_SPI,
.write = cyttsp_spi_write_block_data,
.read = cyttsp_spi_read_block_data,
};
static int cyttsp4_spi_probe(struct spi_device *spi)
{
struct cyttsp4 *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 = cyttsp4_probe(&cyttsp_spi_bus_ops, &spi->dev, spi->irq,
CY_SPI_DATA_BUF_SIZE);
return PTR_ERR_OR_ZERO(ts);
}
static int cyttsp4_spi_remove(struct spi_device *spi)
{
struct cyttsp4 *ts = spi_get_drvdata(spi);
cyttsp4_remove(ts);
return 0;
}
static struct spi_driver cyttsp4_spi_driver = {
.driver = {
.name = CYTTSP4_SPI_NAME,
.pm = &cyttsp4_pm_ops,
},
.probe = cyttsp4_spi_probe,
.remove = cyttsp4_spi_remove,
};
module_spi_driver(cyttsp4_spi_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP) SPI driver");
MODULE_AUTHOR("Cypress");
MODULE_ALIAS("spi:cyttsp4");