[PATCH v2 3/3] Input: cyttsp4 - SPI driver for Cypress TMA4XX touchscreen devices

From: Ferruh Yigit
Date: Fri Sep 14 2012 - 13:49:25 EST

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@xxxxxxxxxxx>
---
drivers/input/touchscreen/Kconfig | 12 ++
drivers/input/touchscreen/Makefile | 3 +
drivers/input/touchscreen/cyttsp4_spi.c | 318 +++++++++++++++++++++++++++++++
drivers/input/touchscreen/cyttsp4_spi.h | 34 ++++
4 files changed, 367 insertions(+)
create mode 100644 drivers/input/touchscreen/cyttsp4_spi.c
create mode 100644 drivers/input/touchscreen/cyttsp4_spi.h

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index fcc1c82..59706e8 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -224,6 +224,18 @@ config TOUCHSCREEN_CYPRESS_CYTTSP4_I2C
Say Y here to enable I2C bus interface to TTSP
touchscreen controller.

+config TOUCHSCREEN_CYPRESS_CYTTSP4_SPI
+ tristate "Cypress TrueTouch Gen4 SPI"
+ depends on TOUCHSCREEN_CYPRESS_CYTTSP4
+ depends on SPI
+ default n
+ help
+ Cypress TrueTouch(tm) Standard Product Generation4
+ SPI bus interface.
+
+ Say Y here to enable SPI bus interface to TTSP
+ touchscreen controller.
+
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 8f5e8ff..585be70 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -75,12 +75,15 @@ obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o
obj-$(CONFIG_TOUCHSCREEN_TPS6507X) += tps6507x-ts.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4) += cyttsp4_core.o
obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_I2C) += cyttsp4_i2c.o
+obj-$(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_SPI) += cyttsp4_spi.o
ifeq ($(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_DEBUG),y)
CFLAGS_cyttsp4_core.o += -DDEBUG
CFLAGS_cyttsp4_i2c.o += -DDEBUG
+CFLAGS_cyttsp4_spi.o += -DDEBUG
endif

ifeq ($(CONFIG_TOUCHSCREEN_CYPRESS_CYTTSP4_VDEBUG),y)
CFLAGS_cyttsp4_core.o += -DVERBOSE_DEBUG
CFLAGS_cyttsp4_i2c.o += -DVERBOSE_DEBUG
+CFLAGS_cyttsp4_spi.o += -DVERBOSE_DEBUG
endif
diff --git a/drivers/input/touchscreen/cyttsp4_spi.c b/drivers/input/touchscreen/cyttsp4_spi.c
new file mode 100644
index 0000000..4aa036e
--- /dev/null
+++ b/drivers/input/touchscreen/cyttsp4_spi.c
@@ -0,0 +1,318 @@
+/*
+ * cyttsp4_spi.c
+ * Cypress TrueTouch(TM) Standard Product V4 SPI Driver module.
+ * Supported parts include:
+ * TMA4XX
+ * TMA1036
+ *
+ * Copyright (C) 2012 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contact Cypress Semiconductor at www.cypress.com <ttdrivers@xxxxxxxxxxx>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/input/cyttsp4.h>
+#include "cyttsp4_core.h"
+#include "cyttsp4_spi.h"
+
+#define CY_SPI_WR_OP 0x00 /* r/~w */
+#define CY_SPI_RD_OP 0x01
+#define CY_SPI_A8_BIT 0x02
+#define CY_SPI_WR_HEADER_BYTES 2
+#define CY_SPI_RD_HEADER_BYTES 1
+#define CY_SPI_SYNC_BYTE 0
+#define CY_SPI_SYNC_ACK 0x62 /* from TRM *A protocol */
+#define CY_SPI_DATA_SIZE (3 * 256)
+#define CY_SPI_BITS_PER_WORD 8
+#define CY_SPI_MAX_REG 512
+
+#define CY_SPI_MAX_HEADER_BYTES \
+ max(CY_SPI_WR_HEADER_BYTES, CY_SPI_RD_HEADER_BYTES)
+
+static int cyttsp4_spi_xfer(u8 op, struct spi_device *spi,
+ u8 reg, u8 *buf, int length)
+{
+ struct device *dev = &spi->dev;
+ struct spi_message msg;
+ struct spi_transfer xfer[2];
+ u8 wr_hdr_buf[CY_SPI_MAX_HEADER_BYTES];
+ u8 rd_hdr_buf[CY_SPI_MAX_HEADER_BYTES];
+ int rc;
+
+ memset(wr_hdr_buf, 0, CY_SPI_MAX_HEADER_BYTES);
+ memset(rd_hdr_buf, 0, CY_SPI_MAX_HEADER_BYTES);
+ memset(xfer, 0, sizeof(xfer));
+
+ spi_message_init(&msg);
+
+ /* Header buffer */
+ xfer[0].tx_buf = wr_hdr_buf;
+ xfer[0].rx_buf = rd_hdr_buf;
+
+ switch (op) {
+ case CY_SPI_WR_OP:
+ if (length + CY_SPI_WR_HEADER_BYTES > CY_SPI_DATA_SIZE) {
+ dev_vdbg(dev,
+ "%s: length+%d=%d is greater than SPI max=%d\n",
+ __func__, CY_SPI_WR_HEADER_BYTES,
+ length + CY_SPI_WR_HEADER_BYTES,
+ CY_SPI_DATA_SIZE);
+ rc = -EINVAL;
+ goto cyttsp4_spi_xfer_exit;
+ }
+
+ /* Header byte 0 */
+ if (reg > 255)
+ wr_hdr_buf[0] = CY_SPI_WR_OP + CY_SPI_A8_BIT;
+ else
+ wr_hdr_buf[0] = CY_SPI_WR_OP;
+
+ /* Header byte 1 */
+ wr_hdr_buf[1] = reg % 256;
+
+ xfer[0].len = CY_SPI_WR_HEADER_BYTES;
+
+ spi_message_add_tail(&xfer[0], &msg);
+
+ /* Data buffer */
+ if (buf) {
+ xfer[1].tx_buf = buf;
+ xfer[1].len = length;
+
+ spi_message_add_tail(&xfer[1], &msg);
+ }
+ break;
+
+ case CY_SPI_RD_OP:
+ if (!buf) {
+ dev_err(dev, "%s: No read buffer\n", __func__);
+ rc = -EINVAL;
+ goto cyttsp4_spi_xfer_exit;
+ }
+
+ if ((length + CY_SPI_RD_HEADER_BYTES) > CY_SPI_DATA_SIZE) {
+ dev_vdbg(dev,
+ "%s: length+%d=%d is greater than SPI max=%d\n",
+ __func__, CY_SPI_RD_HEADER_BYTES,
+ length + CY_SPI_RD_HEADER_BYTES,
+ CY_SPI_DATA_SIZE);
+ rc = -EINVAL;
+ goto cyttsp4_spi_xfer_exit;
+ }
+
+ /* Header byte 0 */
+ wr_hdr_buf[0] = CY_SPI_RD_OP;
+
+ xfer[0].len = CY_SPI_RD_HEADER_BYTES;
+
+ spi_message_add_tail(&xfer[0], &msg);
+
+ /* Data buffer */
+ xfer[1].rx_buf = buf;
+ xfer[1].len = length;
+
+ spi_message_add_tail(&xfer[1], &msg);
+ break;
+
+ default:
+ dev_dbg(dev, "%s: bad op code=%d\n", __func__, op);
+ rc = -EINVAL;
+ goto cyttsp4_spi_xfer_exit;
+ }
+
+ rc = spi_sync(spi, &msg);
+ if (rc < 0) {
+ dev_vdbg(dev, "%s: spi_sync() error %d, len=%d, op=%d\n",
+ __func__, rc, xfer[0].len, op);
+ /*
+ * do not return here since probably a bad ACK sequence
+ * let the following ACK check handle any errors and
+ * allow silent retries
+ */
+ }
+
+ if (rd_hdr_buf[CY_SPI_SYNC_BYTE] != CY_SPI_SYNC_ACK)
+ /* signal ACK error so silent retry */
+ rc = 1;
+ else
+ rc = 0;
+
+cyttsp4_spi_xfer_exit:
+ return rc;
+}
+
+static s32 cyttsp4_spi_read_block_data(struct spi_device *spi, u8 addr,
+ size_t length, void *data)
+{
+ int rc = 0;
+ struct device *dev = &spi->dev;
+
+ dev_vdbg(dev, "%s: Enter\n", __func__);
+
+ /* Write address */
+ rc = cyttsp4_spi_xfer(CY_SPI_WR_OP, spi, addr, NULL, 0);
+ if (rc < 0) {
+ dev_err(dev, "%s: Fail write address r=%d\n", __func__, rc);
+ return rc;
+ }
+
+ /* Read data */
+ rc = cyttsp4_spi_xfer(CY_SPI_RD_OP, spi, addr, data, length);
+ if (rc < 0) {
+ dev_err(dev, "%s: Fail read r=%d\n", __func__, rc);
+ /*
+ * Do not print the above error if the data sync bytes
+ * were not found.
+ * This is a normal condition for the bootloader loader
+ * startup and need to retry until data sync bytes are found.
+ */
+ } else if (rc > 0)
+ /* Now signal fail; so retry can be done */
+ rc = -EIO;
+
+ return rc;
+}
+
+static s32 cyttsp4_spi_write_block_data(struct spi_device *spi, u8 addr,
+ size_t length, const void *data)
+{
+ int rc = 0;
+ struct device *dev = &spi->dev;
+
+ dev_vdbg(dev, "%s: Enter\n", __func__);
+
+ rc = cyttsp4_spi_xfer(CY_SPI_WR_OP, spi, addr, (void *)data, length);
+ if (rc < 0) {
+ dev_err(dev, "%s: Fail write r=%d\n", __func__, rc);
+ /*
+ * Do not print the above error if the data sync bytes
+ * were not found.
+ * This is a normal condition for the bootloader loader
+ * startup and need to retry until data sync bytes are found.
+ */
+ } else if (rc > 0)
+ /* Now signal fail; so retry can be done */
+ rc = -EIO;
+
+ return rc;
+}
+
+static int cyttsp4_spi_write(struct device *dev, u8 addr,
+ const void *buf, int size)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ int rc;
+
+ rc = cyttsp4_spi_write_block_data(spi, addr, size, buf);
+
+ return rc;
+}
+
+static int cyttsp4_spi_read(struct device *dev, u8 addr,
+ void *buf, int size)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ int rc;
+
+ rc = cyttsp4_spi_read_block_data(spi, addr, size, buf);
+
+ return rc;
+}
+
+static struct cyttsp4_bus_ops ops = {
+ .bustype = BUS_SPI,
+ .write = cyttsp4_spi_write,
+ .read = cyttsp4_spi_read,
+};
+
+static int __devinit cyttsp4_spi_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ int rc = 0;
+
+ dev_dbg(dev, "%s: Probing ...\n", __func__);
+
+ spi->bits_per_word = CY_SPI_BITS_PER_WORD;
+ spi->mode = SPI_MODE_0;
+
+ rc = spi_setup(spi);
+ if (rc < 0) {
+ dev_err(dev, "%s: SPI setup error %d\n", __func__, rc);
+ return rc;
+ }
+
+ rc = cyttsp4_probe(dev, &ops, NULL);
+ if (rc) {
+ dev_err(dev, "%s: Error on probe %s\n", __func__,
+ CYTTSP4_SPI_NAME);
+ goto probe_err;
+ }
+
+ dev_info(dev, "%s: Successful prob %s\n", __func__, CYTTSP4_SPI_NAME);
+
+ return 0;
+
+probe_err:
+ return rc;
+}
+
+static int __devexit cyttsp4_spi_remove(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+
+ dev_info(dev, "%s\n", __func__);
+ cyttsp4_remove(dev);
+ return 0;
+}
+
+static struct spi_driver cyttsp4_spi_driver = {
+ .driver = {
+ .name = CYTTSP4_SPI_NAME,
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ .pm = &cyttsp4_pm_ops,
+ },
+ .probe = cyttsp4_spi_probe,
+ .remove = __devexit_p(cyttsp4_spi_remove),
+};
+
+static int __init cyttsp4_spi_init(void)
+{
+ int err;
+
+ err = spi_register_driver(&cyttsp4_spi_driver);
+ pr_info("%s: Cypress TTSP SPI Touchscreen Driver (Built %s) returned %d\n",
+ __func__, CY_DRIVER_DATE, err);
+
+ return err;
+}
+module_init(cyttsp4_spi_init);
+
+static void __exit cyttsp4_spi_exit(void)
+{
+ spi_unregister_driver(&cyttsp4_spi_driver);
+ pr_info("%s: module exit\n", __func__);
+}
+module_exit(cyttsp4_spi_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP) SPI driver");
+MODULE_AUTHOR("Cypress");
diff --git a/drivers/input/touchscreen/cyttsp4_spi.h b/drivers/input/touchscreen/cyttsp4_spi.h
new file mode 100644
index 0000000..82dc065
--- /dev/null
+++ b/drivers/input/touchscreen/cyttsp4_spi.h
@@ -0,0 +1,34 @@
+/*
+ * cyttsp4_spi.h
+ * Cypress TrueTouch(TM) Standard Product V4 SPI Driver module.
+ * For use with Cypress Txx4xx parts.
+ * Supported parts include:
+ * TMA4XX
+ * TMA1036
+ *
+ * Copyright (C) 2012 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contact Cypress Semiconductor at www.cypress.com <ttdrivers@xxxxxxxxxxx>
+ *
+ */
+
+#ifndef _LINUX_CYTTSP4_SPI_H
+#define _LINUX_CYTTSP4_SPI_H
+
+#define CYTTSP4_SPI_NAME "cyttsp4_spi_adapter"
+
+#endif /* _LINUX_CYTTSP4_SPI_H */
--
1.7.9.5


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