spi: Add SuperH HSPI prototype driver

This patch adds SuperH HSPI driver.
It is still prototype driver, but has enough function at this point.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 364 insertions, 0 deletions

diff --git a/drivers/spi/spi-sh-hspi.c b/drivers/spi/spi-sh-hspi.c
new file mode 100644
index 0000000..8356ec8
--- /dev/null
+++ b/drivers/spi/spi-sh-hspi.c
@@ -0,0 +1,364 @@
+/*
+ * SuperH HSPI bus driver
+ *
+ * Copyright (C) 2011  Kuninori Morimoto
+ *
+ * Based on spi-sh.c:
+ * Based on pxa2xx_spi.c:
+ * Copyright (C) 2011 Renesas Solutions Corp.
+ * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/io.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/sh_hspi.h>
+
+#define SPCR	0x00
+#define SPSR	0x04
+#define SPSCR	0x08
+#define SPTBR	0x0C
+#define SPRBR	0x10
+#define SPCR2	0x14
+
+/* SPSR */
+#define RXFL	(1 << 2)
+
+#define hspi2info(h)	(h->dev->platform_data)
+
+struct hspi_priv {
+	void __iomem *addr;
+	struct spi_master *master;
+	struct list_head queue;
+	struct workqueue_struct *workqueue;
+	struct work_struct ws;
+	struct device *dev;
+	spinlock_t lock;
+};
+
+/*
+ *		basic function
+ */
+static void hspi_write(struct hspi_priv *hspi, int reg, u32 val)
+{
+	iowrite32(val, hspi->addr + reg);
+}
+
+static u32 hspi_read(struct hspi_priv *hspi, int reg)
+{
+	return ioread32(hspi->addr + reg);
+}
+
+/*
+ *		transfer function
+ */
+static int hspi_status_check_timeout(struct hspi_priv *hspi, u32 mask, u32 val)
+{
+	int t = 256;
+
+	while (t--) {
+		if ((mask & hspi_read(hspi, SPSR)) == val)
+			return 0;
+
+		msleep(20);
+	}
+
+	dev_err(hspi->dev, "timeout\n");
+	return -ETIMEDOUT;
+}
+
+static int hspi_push(struct hspi_priv *hspi, struct spi_message *msg,
+		     struct spi_transfer *t)
+{
+	int i, ret;
+	u8 *data = (u8 *)t->tx_buf;
+
+	/*
+	 * FIXME
+	 * very simple, but polling transfer
+	 */
+	for (i = 0; i < t->len; i++) {
+		/* wait remains */
+		ret = hspi_status_check_timeout(hspi, 0x1, 0x0);
+		if (ret < 0)
+			return ret;
+
+		hspi_write(hspi, SPTBR, (u32)data[i]);
+
+		/* wait recive */
+		ret = hspi_status_check_timeout(hspi, 0x4, 0x4);
+		if (ret < 0)
+			return ret;
+
+		/* dummy read */
+		hspi_read(hspi, SPRBR);
+	}
+
+	return 0;
+}
+
+static int hspi_pop(struct hspi_priv *hspi, struct spi_message *msg,
+		    struct spi_transfer *t)
+{
+	int i, ret;
+	u8 *data = (u8 *)t->rx_buf;
+
+	/*
+	 * FIXME
+	 * very simple, but polling receive
+	 */
+	for (i = 0; i < t->len; i++) {
+		/* wait remains */
+		ret = hspi_status_check_timeout(hspi, 0x1, 0);
+		if (ret < 0)
+			return ret;
+
+		/* dummy write */
+		hspi_write(hspi, SPTBR, 0x0);
+
+		/* wait recive */
+		ret = hspi_status_check_timeout(hspi, 0x4, 0x4);
+		if (ret < 0)
+			return ret;
+
+		data[i] = (u8)hspi_read(hspi, SPRBR);
+	}
+
+	return 0;
+}
+
+static void hspi_work(struct work_struct *work)
+{
+	struct hspi_priv *hspi = container_of(work, struct hspi_priv, ws);
+	struct sh_hspi_info *info = hspi2info(hspi);
+	struct spi_message *msg;
+	struct spi_transfer *t;
+	unsigned long flags;
+	u32 data;
+	int ret;
+
+	dev_dbg(hspi->dev, "%s\n", __func__);
+
+	/************************ pm enable ************************/
+	pm_runtime_get_sync(hspi->dev);
+
+	/* setup first of all in under pm_runtime */
+	data = SH_HSPI_CLK_DIVC(info->flags);
+
+	if (info->flags & SH_HSPI_FBS)
+		data |= 1 << 7;
+	if (info->flags & SH_HSPI_CLKP_HIGH)
+		data |= 1 << 6;
+	if (info->flags & SH_HSPI_IDIV_DIV128)
+		data |= 1 << 5;
+
+	hspi_write(hspi, SPCR, data);
+	hspi_write(hspi, SPSR, 0x0);
+	hspi_write(hspi, SPSCR, 0x1);	/* master mode */
+
+	while (1) {
+		msg = NULL;
+
+		/************************ spin lock ************************/
+		spin_lock_irqsave(&hspi->lock, flags);
+		if (!list_empty(&hspi->queue)) {
+			msg = list_entry(hspi->queue.next,
+					 struct spi_message, queue);
+			list_del_init(&msg->queue);
+		}
+		spin_unlock_irqrestore(&hspi->lock, flags);
+		/************************ spin unlock ************************/
+		if (!msg)
+			break;
+
+		ret = 0;
+		list_for_each_entry(t, &msg->transfers, transfer_list) {
+			if (t->tx_buf) {
+				ret = hspi_push(hspi, msg, t);
+				if (ret < 0)
+					goto error;
+			}
+			if (t->rx_buf) {
+				ret = hspi_pop(hspi, msg, t);
+				if (ret < 0)
+					goto error;
+			}
+			msg->actual_length += t->len;
+		}
+error:
+		msg->status = ret;
+		msg->complete(msg->context);
+	}
+
+	pm_runtime_put_sync(hspi->dev);
+	/************************ pm disable ************************/
+
+	return;
+}
+
+/*
+ *		spi master function
+ */
+static int hspi_setup(struct spi_device *spi)
+{
+	struct hspi_priv *hspi = spi_master_get_devdata(spi->master);
+	struct device *dev = hspi->dev;
+
+	if (8 != spi->bits_per_word) {
+		dev_err(dev, "bits_per_word should be 8\n");
+		return -EIO;
+	}
+
+	dev_dbg(dev, "%s setup\n", spi->modalias);
+
+	return 0;
+}
+
+static void hspi_cleanup(struct spi_device *spi)
+{
+	struct hspi_priv *hspi = spi_master_get_devdata(spi->master);
+	struct device *dev = hspi->dev;
+
+	dev_dbg(dev, "%s cleanup\n", spi->modalias);
+}
+
+static int hspi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+	struct hspi_priv *hspi = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	/************************ spin lock ************************/
+	spin_lock_irqsave(&hspi->lock, flags);
+
+	msg->actual_length	= 0;
+	msg->status		= -EINPROGRESS;
+	list_add_tail(&msg->queue, &hspi->queue);
+
+	spin_unlock_irqrestore(&hspi->lock, flags);
+	/************************ spin unlock ************************/
+
+	queue_work(hspi->workqueue, &hspi->ws);
+
+	return 0;
+}
+
+static int __devinit hspi_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct spi_master *master;
+	struct hspi_priv *hspi;
+	int ret;
+
+	/* get base addr */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "invalid resource\n");
+		return -EINVAL;
+	}
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*hspi));
+	if (!master) {
+		dev_err(&pdev->dev, "spi_alloc_master error.\n");
+		return -ENOMEM;
+	}
+
+	hspi = spi_master_get_devdata(master);
+	dev_set_drvdata(&pdev->dev, hspi);
+
+	/* init hspi */
+	hspi->master	= master;
+	hspi->dev	= &pdev->dev;
+	hspi->addr	= devm_ioremap(hspi->dev,
+				       res->start, resource_size(res));
+	if (!hspi->addr) {
+		dev_err(&pdev->dev, "ioremap error.\n");
+		ret = -ENOMEM;
+		goto error1;
+	}
+	hspi->workqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
+	if (!hspi->workqueue) {
+		dev_err(&pdev->dev, "create workqueue error\n");
+		ret = -EBUSY;
+		goto error2;
+	}
+
+	spin_lock_init(&hspi->lock);
+	INIT_LIST_HEAD(&hspi->queue);
+	INIT_WORK(&hspi->ws, hspi_work);
+
+	master->num_chipselect	= 1;
+	master->bus_num		= pdev->id;
+	master->setup		= hspi_setup;
+	master->transfer	= hspi_transfer;
+	master->cleanup		= hspi_cleanup;
+	master->mode_bits	= SPI_CPOL | SPI_CPHA;
+	ret = spi_register_master(master);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "spi_register_master error.\n");
+		goto error3;
+	}
+
+	pm_runtime_enable(&pdev->dev);
+
+	dev_info(&pdev->dev, "probed\n");
+
+	return 0;
+
+ error3:
+	destroy_workqueue(hspi->workqueue);
+ error2:
+	devm_iounmap(hspi->dev, hspi->addr);
+ error1:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int __devexit hspi_remove(struct platform_device *pdev)
+{
+	struct hspi_priv *hspi = dev_get_drvdata(&pdev->dev);
+
+	pm_runtime_disable(&pdev->dev);
+
+	spi_unregister_master(hspi->master);
+	destroy_workqueue(hspi->workqueue);
+	devm_iounmap(hspi->dev, hspi->addr);
+
+	return 0;
+}
+
+static struct platform_driver hspi_driver = {
+	.probe = hspi_probe,
+	.remove = __devexit_p(hspi_remove),
+	.driver = {
+		.name = "sh-hspi",
+		.owner = THIS_MODULE,
+	},
+};
+module_platform_driver(hspi_driver);
+
+MODULE_DESCRIPTION("SuperH HSPI bus driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
+MODULE_ALIAS("platform:sh_spi");