Initial import

1 files changed, 214 insertions, 0 deletions

diff --git a/drivers/spi/spi-clps711x.c b/drivers/spi/spi-clps711x.c
new file mode 100644
index 000000000..8c30de031
--- /dev/null
+++ b/drivers/spi/spi-clps711x.c
@@ -0,0 +1,214 @@
+/*
+ *  CLPS711X SPI bus driver
+ *
+ *  Copyright (C) 2012-2014 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/clps711x.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_data/spi-clps711x.h>
+
+#define DRIVER_NAME	"spi-clps711x"
+
+#define SYNCIO_FRMLEN(x)	((x) << 8)
+#define SYNCIO_TXFRMEN		(1 << 14)
+
+struct spi_clps711x_data {
+	void __iomem		*syncio;
+	struct regmap		*syscon;
+	struct clk		*spi_clk;
+
+	u8			*tx_buf;
+	u8			*rx_buf;
+	unsigned int		bpw;
+	int			len;
+};
+
+static int spi_clps711x_setup(struct spi_device *spi)
+{
+	/* We are expect that SPI-device is not selected */
+	gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
+
+	return 0;
+}
+
+static int spi_clps711x_prepare_message(struct spi_master *master,
+					struct spi_message *msg)
+{
+	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+	struct spi_device *spi = msg->spi;
+
+	/* Setup mode for transfer */
+	return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
+				  (spi->mode & SPI_CPHA) ?
+				  SYSCON3_ADCCKNSEN : 0);
+}
+
+static int spi_clps711x_transfer_one(struct spi_master *master,
+				     struct spi_device *spi,
+				     struct spi_transfer *xfer)
+{
+	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+	u8 data;
+
+	clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
+
+	hw->len = xfer->len;
+	hw->bpw = xfer->bits_per_word;
+	hw->tx_buf = (u8 *)xfer->tx_buf;
+	hw->rx_buf = (u8 *)xfer->rx_buf;
+
+	/* Initiate transfer */
+	data = hw->tx_buf ? *hw->tx_buf++ : 0;
+	writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
+
+	return 1;
+}
+
+static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
+{
+	struct spi_master *master = dev_id;
+	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+	u8 data;
+
+	/* Handle RX */
+	data = readb(hw->syncio);
+	if (hw->rx_buf)
+		*hw->rx_buf++ = data;
+
+	/* Handle TX */
+	if (--hw->len > 0) {
+		data = hw->tx_buf ? *hw->tx_buf++ : 0;
+		writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
+		       hw->syncio);
+	} else
+		spi_finalize_current_transfer(master);
+
+	return IRQ_HANDLED;
+}
+
+static int spi_clps711x_probe(struct platform_device *pdev)
+{
+	struct spi_clps711x_data *hw;
+	struct spi_clps711x_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct spi_master *master;
+	struct resource *res;
+	int i, irq, ret;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform data supplied\n");
+		return -EINVAL;
+	}
+
+	if (pdata->num_chipselect < 1) {
+		dev_err(&pdev->dev, "At least one CS must be defined\n");
+		return -EINVAL;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*hw));
+	if (!master)
+		return -ENOMEM;
+
+	master->cs_gpios = devm_kzalloc(&pdev->dev, sizeof(int) *
+					pdata->num_chipselect, GFP_KERNEL);
+	if (!master->cs_gpios) {
+		ret = -ENOMEM;
+		goto err_out;
+	}
+
+	master->bus_num = pdev->id;
+	master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
+	master->bits_per_word_mask =  SPI_BPW_RANGE_MASK(1, 8);
+	master->num_chipselect = pdata->num_chipselect;
+	master->setup = spi_clps711x_setup;
+	master->prepare_message = spi_clps711x_prepare_message;
+	master->transfer_one = spi_clps711x_transfer_one;
+
+	hw = spi_master_get_devdata(master);
+
+	for (i = 0; i < master->num_chipselect; i++) {
+		master->cs_gpios[i] = pdata->chipselect[i];
+		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
+					DRIVER_NAME);
+		if (ret) {
+			dev_err(&pdev->dev, "Can't get CS GPIO %i\n", i);
+			goto err_out;
+		}
+	}
+
+	hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(hw->spi_clk)) {
+		ret = PTR_ERR(hw->spi_clk);
+		goto err_out;
+	}
+
+	hw->syscon = syscon_regmap_lookup_by_pdevname("syscon.3");
+	if (IS_ERR(hw->syscon)) {
+		ret = PTR_ERR(hw->syscon);
+		goto err_out;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	hw->syncio = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(hw->syncio)) {
+		ret = PTR_ERR(hw->syncio);
+		goto err_out;
+	}
+
+	/* Disable extended mode due hardware problems */
+	regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
+
+	/* Clear possible pending interrupt */
+	readl(hw->syncio);
+
+	ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
+			       dev_name(&pdev->dev), master);
+	if (ret)
+		goto err_out;
+
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (!ret) {
+		dev_info(&pdev->dev,
+			 "SPI bus driver initialized. Master clock %u Hz\n",
+			 master->max_speed_hz);
+		return 0;
+	}
+
+	dev_err(&pdev->dev, "Failed to register master\n");
+
+err_out:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static struct platform_driver clps711x_spi_driver = {
+	.driver	= {
+		.name	= DRIVER_NAME,
+	},
+	.probe	= spi_clps711x_probe,
+};
+module_platform_driver(clps711x_spi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("CLPS711X SPI bus driver");
+MODULE_ALIAS("platform:" DRIVER_NAME);