[PATCH v3 4/4] Input: cyttsp4 - SPI driver for Cypress TMA4XX touchscreen devices

Ferruh Yigit
2013-06-04T09:36:13Z

Cypress TrueTouch(tm) Standard Product controllers,
Generation4 devices, SPI adapter module.

This driver adds communication support with TTSP controller
using SPI bus.

Signed-off-by: Ferruh Yigit <fery@cypress.com>
---
drivers/input/touchscreen/Kconfig | 9 ++
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/cyttsp4_spi.c | 205 +++++++++++++++++++++++++++++++
3 files changed, 215 insertions(+)
create mode 100644 drivers/input/touchscreen/cyttsp4_spi.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 1645e8e..2d70089 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -188,6 +188,15 @@ config TOUCHSCREEN_CYTTSP4_I2C
To compile this driver as a module, choose M here: the
module will be called cyttsp4_i2c.

+config TOUCHSCREEN_CYTTSP4_SPI
+ tristate "support SPI bus connection"
+ depends on TOUCHSCREEN_CYTTSP4_CORE && SPI_MASTER
+ help
+ Say Y here if the touchscreen is connected via SPI bus.
+
+ To compile this driver as a module, choose M here: the
+ module will be called cyttsp4_spi.
+
config TOUCHSCREEN_DA9034
tristate "Touchscreen support for Dialog Semiconductor DA9034"
depends on PMIC_DA903X
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 1ef807c..f5216c1 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_TOUCHSCREEN_CYTTSP_I2C) += cyttsp_i2c.o cyttsp_i2c_common.o
obj-$(CONFIG_TOUCHSCREEN_CYTTSP_SPI) += cyttsp_spi.o
obj-$(CONFIG_TOUCHSCREEN_CYTTSP4_CORE) += cyttsp4_core.o
obj-$(CONFIG_TOUCHSCREEN_CYTTSP4_I2C) += cyttsp4_i2c.o cyttsp_i2c_common.o
+obj-$(CONFIG_TOUCHSCREEN_CYTTSP4_SPI) += cyttsp4_spi.o
obj-$(CONFIG_TOUCHSCREEN_DA9034) += da9034-ts.o
obj-$(CONFIG_TOUCHSCREEN_DA9052) += da9052_tsi.o
obj-$(CONFIG_TOUCHSCREEN_DYNAPRO) += dynapro.o
diff --git a/drivers/input/touchscreen/cyttsp4_spi.c b/drivers/input/touchscreen/cyttsp4_spi.c
new file mode 100644
index 0000000..f8f891b
--- /dev/null
+++ b/drivers/input/touchscreen/cyttsp4_spi.c
@@ -0,0 +1,205 @@
+/*
+ * 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
+ *
+ * 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.
+ *
+ * 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, u8 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);
+
+ if (reg > 255)
+ wr_buf[0] = op + CY_SPI_A8_BIT;
+ else
+ wr_buf[0] = op;
+ if (op == CY_SPI_WR_OP)
+ wr_buf[1] = reg % 256;
+ if (op == CY_SPI_WR_OP && 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,
+ u8 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,
+ u8 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);
+
+ if (IS_ERR(ts))
+ return PTR_ERR(ts);
+
+ return 0;
+}
+
+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,
+ .owner = THIS_MODULE,
+ .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");
--
1.7.9.5