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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 | // SPDX-License-Identifier: GPL-2.0-only /* * 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 * * 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, 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[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); wr_buf[0] = op + (((reg >> 8) & 0x1) ? CY_SPI_A8_BIT : 0); if (op == CY_SPI_WR_OP) { wr_buf[1] = reg & 0xFF; if (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, u16 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, 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 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); return PTR_ERR_OR_ZERO(ts); } static void cyttsp4_spi_remove(struct spi_device *spi) { struct cyttsp4 *ts = spi_get_drvdata(spi); cyttsp4_remove(ts); } static struct spi_driver cyttsp4_spi_driver = { .driver = { .name = CYTTSP4_SPI_NAME, .pm = pm_ptr(&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"); |