1 /* 2 * Source for: 3 * Cypress TrueTouch(TM) Standard Product (TTSP) SPI touchscreen driver. 4 * For use with Cypress Txx4xx parts. 5 * Supported parts include: 6 * TMA4XX 7 * TMA1036 8 * 9 * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc. 10 * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org> 11 * Copyright (C) 2013 Cypress Semiconductor 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * version 2, and only version 2, as published by the 16 * Free Software Foundation. 17 * 18 * This program is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 * GNU General Public License for more details. 22 * 23 * Contact Cypress Semiconductor at www.cypress.com <ttdrivers@cypress.com> 24 * 25 */ 26 27 #include "cyttsp4_core.h" 28 29 #include <linux/delay.h> 30 #include <linux/input.h> 31 #include <linux/spi/spi.h> 32 33 #define CY_SPI_WR_OP 0x00 /* r/~w */ 34 #define CY_SPI_RD_OP 0x01 35 #define CY_SPI_BITS_PER_WORD 8 36 #define CY_SPI_A8_BIT 0x02 37 #define CY_SPI_WR_HEADER_BYTES 2 38 #define CY_SPI_RD_HEADER_BYTES 1 39 #define CY_SPI_CMD_BYTES 2 40 #define CY_SPI_SYNC_BYTE 0 41 #define CY_SPI_SYNC_ACK 0x62 /* from TRM *A protocol */ 42 #define CY_SPI_DATA_SIZE (2 * 256) 43 44 #define CY_SPI_DATA_BUF_SIZE (CY_SPI_CMD_BYTES + CY_SPI_DATA_SIZE) 45 46 static int cyttsp_spi_xfer(struct device *dev, u8 *xfer_buf, 47 u8 op, u8 reg, u8 *buf, int length) 48 { 49 struct spi_device *spi = to_spi_device(dev); 50 struct spi_message msg; 51 struct spi_transfer xfer[2]; 52 u8 *wr_buf = &xfer_buf[0]; 53 u8 rd_buf[CY_SPI_CMD_BYTES]; 54 int retval; 55 int i; 56 57 if (length > CY_SPI_DATA_SIZE) { 58 dev_err(dev, "%s: length %d is too big.\n", 59 __func__, length); 60 return -EINVAL; 61 } 62 63 memset(wr_buf, 0, CY_SPI_DATA_BUF_SIZE); 64 memset(rd_buf, 0, CY_SPI_CMD_BYTES); 65 66 if (reg > 255) 67 wr_buf[0] = op + CY_SPI_A8_BIT; 68 else 69 wr_buf[0] = op; 70 if (op == CY_SPI_WR_OP) 71 wr_buf[1] = reg % 256; 72 if (op == CY_SPI_WR_OP && length > 0) 73 memcpy(wr_buf + CY_SPI_CMD_BYTES, buf, length); 74 75 memset(xfer, 0, sizeof(xfer)); 76 spi_message_init(&msg); 77 78 /* 79 We set both TX and RX buffers because Cypress TTSP 80 requires full duplex operation. 81 */ 82 xfer[0].tx_buf = wr_buf; 83 xfer[0].rx_buf = rd_buf; 84 switch (op) { 85 case CY_SPI_WR_OP: 86 xfer[0].len = length + CY_SPI_CMD_BYTES; 87 spi_message_add_tail(&xfer[0], &msg); 88 break; 89 90 case CY_SPI_RD_OP: 91 xfer[0].len = CY_SPI_RD_HEADER_BYTES; 92 spi_message_add_tail(&xfer[0], &msg); 93 94 xfer[1].rx_buf = buf; 95 xfer[1].len = length; 96 spi_message_add_tail(&xfer[1], &msg); 97 break; 98 99 default: 100 dev_err(dev, "%s: bad operation code=%d\n", __func__, op); 101 return -EINVAL; 102 } 103 104 retval = spi_sync(spi, &msg); 105 if (retval < 0) { 106 dev_dbg(dev, "%s: spi_sync() error %d, len=%d, op=%d\n", 107 __func__, retval, xfer[1].len, op); 108 109 /* 110 * do not return here since was a bad ACK sequence 111 * let the following ACK check handle any errors and 112 * allow silent retries 113 */ 114 } 115 116 if (rd_buf[CY_SPI_SYNC_BYTE] != CY_SPI_SYNC_ACK) { 117 dev_dbg(dev, "%s: operation %d failed\n", __func__, op); 118 119 for (i = 0; i < CY_SPI_CMD_BYTES; i++) 120 dev_dbg(dev, "%s: test rd_buf[%d]:0x%02x\n", 121 __func__, i, rd_buf[i]); 122 for (i = 0; i < length; i++) 123 dev_dbg(dev, "%s: test buf[%d]:0x%02x\n", 124 __func__, i, buf[i]); 125 126 return -EIO; 127 } 128 129 return 0; 130 } 131 132 static int cyttsp_spi_read_block_data(struct device *dev, u8 *xfer_buf, 133 u8 addr, u8 length, void *data) 134 { 135 int rc; 136 137 rc = cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_WR_OP, addr, NULL, 0); 138 if (rc) 139 return rc; 140 else 141 return cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_RD_OP, addr, data, 142 length); 143 } 144 145 static int cyttsp_spi_write_block_data(struct device *dev, u8 *xfer_buf, 146 u8 addr, u8 length, const void *data) 147 { 148 return cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_WR_OP, addr, (void *)data, 149 length); 150 } 151 152 static const struct cyttsp4_bus_ops cyttsp_spi_bus_ops = { 153 .bustype = BUS_SPI, 154 .write = cyttsp_spi_write_block_data, 155 .read = cyttsp_spi_read_block_data, 156 }; 157 158 static int cyttsp4_spi_probe(struct spi_device *spi) 159 { 160 struct cyttsp4 *ts; 161 int error; 162 163 /* Set up SPI*/ 164 spi->bits_per_word = CY_SPI_BITS_PER_WORD; 165 spi->mode = SPI_MODE_0; 166 error = spi_setup(spi); 167 if (error < 0) { 168 dev_err(&spi->dev, "%s: SPI setup error %d\n", 169 __func__, error); 170 return error; 171 } 172 173 ts = cyttsp4_probe(&cyttsp_spi_bus_ops, &spi->dev, spi->irq, 174 CY_SPI_DATA_BUF_SIZE); 175 176 if (IS_ERR(ts)) 177 return PTR_ERR(ts); 178 179 return 0; 180 } 181 182 static int cyttsp4_spi_remove(struct spi_device *spi) 183 { 184 struct cyttsp4 *ts = spi_get_drvdata(spi); 185 cyttsp4_remove(ts); 186 187 return 0; 188 } 189 190 static struct spi_driver cyttsp4_spi_driver = { 191 .driver = { 192 .name = CYTTSP4_SPI_NAME, 193 .owner = THIS_MODULE, 194 .pm = &cyttsp4_pm_ops, 195 }, 196 .probe = cyttsp4_spi_probe, 197 .remove = cyttsp4_spi_remove, 198 }; 199 200 module_spi_driver(cyttsp4_spi_driver); 201 202 MODULE_LICENSE("GPL"); 203 MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP) SPI driver"); 204 MODULE_AUTHOR("Cypress"); 205 MODULE_ALIAS("spi:cyttsp4"); 206