199 lines
5 KiB
C
199 lines
5 KiB
C
/*
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* Source for:
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* Cypress TrueTouch(TM) Standard Product (TTSP) SPI touchscreen driver.
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* For use with Cypress Txx3xx parts.
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* Supported parts include:
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* CY8CTST341
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* CY8CTMA340
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*
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* Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
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* Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2, and only version 2, as published by the
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* Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
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*
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*/
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#include "cyttsp_core.h"
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#include <linux/delay.h>
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#include <linux/input.h>
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#include <linux/spi/spi.h>
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#define CY_SPI_WR_OP 0x00 /* r/~w */
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#define CY_SPI_RD_OP 0x01
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#define CY_SPI_CMD_BYTES 4
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#define CY_SPI_SYNC_BYTE 2
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#define CY_SPI_SYNC_ACK1 0x62 /* from protocol v.2 */
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#define CY_SPI_SYNC_ACK2 0x9D /* from protocol v.2 */
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#define CY_SPI_DATA_SIZE 128
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#define CY_SPI_DATA_BUF_SIZE (CY_SPI_CMD_BYTES + CY_SPI_DATA_SIZE)
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#define CY_SPI_BITS_PER_WORD 8
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static int cyttsp_spi_xfer(struct cyttsp *ts,
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u8 op, u8 reg, u8 *buf, int length)
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{
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struct spi_device *spi = to_spi_device(ts->dev);
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struct spi_message msg;
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struct spi_transfer xfer[2];
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u8 *wr_buf = &ts->xfer_buf[0];
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u8 *rd_buf = &ts->xfer_buf[CY_SPI_DATA_BUF_SIZE];
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int retval;
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int i;
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if (length > CY_SPI_DATA_SIZE) {
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dev_err(ts->dev, "%s: length %d is too big.\n",
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__func__, length);
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return -EINVAL;
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}
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memset(wr_buf, 0, CY_SPI_DATA_BUF_SIZE);
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memset(rd_buf, 0, CY_SPI_DATA_BUF_SIZE);
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wr_buf[0] = 0x00; /* header byte 0 */
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wr_buf[1] = 0xFF; /* header byte 1 */
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wr_buf[2] = reg; /* reg index */
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wr_buf[3] = op; /* r/~w */
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if (op == CY_SPI_WR_OP)
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memcpy(wr_buf + CY_SPI_CMD_BYTES, buf, length);
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memset(xfer, 0, sizeof(xfer));
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spi_message_init(&msg);
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/*
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We set both TX and RX buffers because Cypress TTSP
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requires full duplex operation.
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*/
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xfer[0].tx_buf = wr_buf;
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xfer[0].rx_buf = rd_buf;
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switch (op) {
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case CY_SPI_WR_OP:
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xfer[0].len = length + CY_SPI_CMD_BYTES;
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spi_message_add_tail(&xfer[0], &msg);
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break;
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case CY_SPI_RD_OP:
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xfer[0].len = CY_SPI_CMD_BYTES;
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spi_message_add_tail(&xfer[0], &msg);
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xfer[1].rx_buf = buf;
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xfer[1].len = length;
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spi_message_add_tail(&xfer[1], &msg);
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break;
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default:
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dev_err(ts->dev, "%s: bad operation code=%d\n", __func__, op);
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return -EINVAL;
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}
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retval = spi_sync(spi, &msg);
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if (retval < 0) {
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dev_dbg(ts->dev, "%s: spi_sync() error %d, len=%d, op=%d\n",
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__func__, retval, xfer[1].len, op);
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/*
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* do not return here since was a bad ACK sequence
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* let the following ACK check handle any errors and
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* allow silent retries
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*/
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}
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if (rd_buf[CY_SPI_SYNC_BYTE] != CY_SPI_SYNC_ACK1 ||
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rd_buf[CY_SPI_SYNC_BYTE + 1] != CY_SPI_SYNC_ACK2) {
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dev_dbg(ts->dev, "%s: operation %d failed\n", __func__, op);
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for (i = 0; i < CY_SPI_CMD_BYTES; i++)
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dev_dbg(ts->dev, "%s: test rd_buf[%d]:0x%02x\n",
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__func__, i, rd_buf[i]);
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for (i = 0; i < length; i++)
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dev_dbg(ts->dev, "%s: test buf[%d]:0x%02x\n",
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__func__, i, buf[i]);
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return -EIO;
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}
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return 0;
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}
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static int cyttsp_spi_read_block_data(struct cyttsp *ts,
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u8 addr, u8 length, void *data)
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{
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return cyttsp_spi_xfer(ts, CY_SPI_RD_OP, addr, data, length);
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}
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static int cyttsp_spi_write_block_data(struct cyttsp *ts,
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u8 addr, u8 length, const void *data)
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{
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return cyttsp_spi_xfer(ts, CY_SPI_WR_OP, addr, (void *)data, length);
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}
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static const struct cyttsp_bus_ops cyttsp_spi_bus_ops = {
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.bustype = BUS_SPI,
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.write = cyttsp_spi_write_block_data,
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.read = cyttsp_spi_read_block_data,
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};
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static int cyttsp_spi_probe(struct spi_device *spi)
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{
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struct cyttsp *ts;
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int error;
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/* Set up SPI*/
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spi->bits_per_word = CY_SPI_BITS_PER_WORD;
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spi->mode = SPI_MODE_0;
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error = spi_setup(spi);
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if (error < 0) {
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dev_err(&spi->dev, "%s: SPI setup error %d\n",
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__func__, error);
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return error;
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}
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ts = cyttsp_probe(&cyttsp_spi_bus_ops, &spi->dev, spi->irq,
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CY_SPI_DATA_BUF_SIZE * 2);
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if (IS_ERR(ts))
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return PTR_ERR(ts);
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spi_set_drvdata(spi, ts);
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return 0;
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}
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static int cyttsp_spi_remove(struct spi_device *spi)
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{
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struct cyttsp *ts = spi_get_drvdata(spi);
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cyttsp_remove(ts);
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return 0;
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}
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static struct spi_driver cyttsp_spi_driver = {
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.driver = {
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.name = CY_SPI_NAME,
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.owner = THIS_MODULE,
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.pm = &cyttsp_pm_ops,
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},
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.probe = cyttsp_spi_probe,
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.remove = cyttsp_spi_remove,
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};
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module_spi_driver(cyttsp_spi_driver);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP) SPI driver");
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MODULE_AUTHOR("Cypress");
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MODULE_ALIAS("spi:cyttsp");
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