X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Finput%2Ftouchscreen%2Fad7879-spi.c;fp=kernel%2Fdrivers%2Finput%2Ftouchscreen%2Fad7879-spi.c;h=1a7b1143536e1d4a68dd6fb9e1c85cf992afee04;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/input/touchscreen/ad7879-spi.c b/kernel/drivers/input/touchscreen/ad7879-spi.c
new file mode 100644
index 000000000..1a7b11435
--- /dev/null
+++ b/kernel/drivers/input/touchscreen/ad7879-spi.c
@@ -0,0 +1,164 @@
+/*
+ * AD7879/AD7889 touchscreen (SPI bus)
+ *
+ * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/input.h>	/* BUS_SPI */
+#include <linux/pm.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+
+#include "ad7879.h"
+
+#define AD7879_DEVID		0x7A	/* AD7879/AD7889 */
+
+#define MAX_SPI_FREQ_HZ      5000000
+#define AD7879_CMD_MAGIC     0xE000
+#define AD7879_CMD_READ      (1 << 10)
+#define AD7879_CMD(reg)      (AD7879_CMD_MAGIC | ((reg) & 0xF))
+#define AD7879_WRITECMD(reg) (AD7879_CMD(reg))
+#define AD7879_READCMD(reg)  (AD7879_CMD(reg) | AD7879_CMD_READ)
+
+/*
+ * ad7879_read/write are only used for initial setup and for sysfs controls.
+ * The main traffic is done in ad7879_collect().
+ */
+
+static int ad7879_spi_xfer(struct spi_device *spi,
+			   u16 cmd, u8 count, u16 *tx_buf, u16 *rx_buf)
+{
+	struct spi_message msg;
+	struct spi_transfer *xfers;
+	void *spi_data;
+	u16 *command;
+	u16 *_rx_buf = _rx_buf; /* shut gcc up */
+	u8 idx;
+	int ret;
+
+	xfers = spi_data = kzalloc(sizeof(*xfers) * (count + 2), GFP_KERNEL);
+	if (!spi_data)
+		return -ENOMEM;
+
+	spi_message_init(&msg);
+
+	command = spi_data;
+	command[0] = cmd;
+	if (count == 1) {
+		/* ad7879_spi_{read,write} gave us buf on stack */
+		command[1] = *tx_buf;
+		tx_buf = &command[1];
+		_rx_buf = rx_buf;
+		rx_buf = &command[2];
+	}
+
+	++xfers;
+	xfers[0].tx_buf = command;
+	xfers[0].len = 2;
+	spi_message_add_tail(&xfers[0], &msg);
+	++xfers;
+
+	for (idx = 0; idx < count; ++idx) {
+		if (rx_buf)
+			xfers[idx].rx_buf = &rx_buf[idx];
+		if (tx_buf)
+			xfers[idx].tx_buf = &tx_buf[idx];
+		xfers[idx].len = 2;
+		spi_message_add_tail(&xfers[idx], &msg);
+	}
+
+	ret = spi_sync(spi, &msg);
+
+	if (count == 1)
+		_rx_buf[0] = command[2];
+
+	kfree(spi_data);
+
+	return ret;
+}
+
+static int ad7879_spi_multi_read(struct device *dev,
+				 u8 first_reg, u8 count, u16 *buf)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	return ad7879_spi_xfer(spi, AD7879_READCMD(first_reg), count, NULL, buf);
+}
+
+static int ad7879_spi_read(struct device *dev, u8 reg)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	u16 ret, dummy;
+
+	return ad7879_spi_xfer(spi, AD7879_READCMD(reg), 1, &dummy, &ret) ? : ret;
+}
+
+static int ad7879_spi_write(struct device *dev, u8 reg, u16 val)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	u16 dummy;
+
+	return ad7879_spi_xfer(spi, AD7879_WRITECMD(reg), 1, &val, &dummy);
+}
+
+static const struct ad7879_bus_ops ad7879_spi_bus_ops = {
+	.bustype	= BUS_SPI,
+	.read		= ad7879_spi_read,
+	.multi_read	= ad7879_spi_multi_read,
+	.write		= ad7879_spi_write,
+};
+
+static int ad7879_spi_probe(struct spi_device *spi)
+{
+	struct ad7879 *ts;
+	int err;
+
+	/* don't exceed max specified SPI CLK frequency */
+	if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
+		dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
+		return -EINVAL;
+	}
+
+	spi->bits_per_word = 16;
+	err = spi_setup(spi);
+	if (err) {
+	        dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
+	        return err;
+	}
+
+	ts = ad7879_probe(&spi->dev, AD7879_DEVID, spi->irq, &ad7879_spi_bus_ops);
+	if (IS_ERR(ts))
+		return PTR_ERR(ts);
+
+	spi_set_drvdata(spi, ts);
+
+	return 0;
+}
+
+static int ad7879_spi_remove(struct spi_device *spi)
+{
+	struct ad7879 *ts = spi_get_drvdata(spi);
+
+	ad7879_remove(ts);
+
+	return 0;
+}
+
+static struct spi_driver ad7879_spi_driver = {
+	.driver = {
+		.name	= "ad7879",
+		.owner	= THIS_MODULE,
+		.pm	= &ad7879_pm_ops,
+	},
+	.probe		= ad7879_spi_probe,
+	.remove		= ad7879_spi_remove,
+};
+
+module_spi_driver(ad7879_spi_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:ad7879");