/* * 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 * * 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 "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 int cyttsp_spi_remove(struct spi_device *spi) { struct cyttsp *ts = spi_get_drvdata(spi); cyttsp_remove(ts); return 0; } static struct spi_driver cyttsp_spi_driver = { .driver = { .name = CY_SPI_NAME, .owner = THIS_MODULE, .pm = &cyttsp_pm_ops, }, .probe = cyttsp_spi_probe, .remove = cyttsp_spi_remove, }; 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");