aboutsummaryrefslogtreecommitdiff
path: root/drivers/spi/spi-sh-hspi.c
diff options
context:
space:
mode:
authorKuninori Morimoto <kuninori.morimoto.gx@renesas.com>2012-03-01 17:10:17 -0800
committerGrant Likely <grant.likely@secretlab.ca>2012-03-09 09:50:09 -0700
commitd1c8bbd793e4c2f346f8788ad312f5b5b530aff5 (patch)
tree136cf736f0a21f4414fa26ea480848e48e9aadbe /drivers/spi/spi-sh-hspi.c
parentffbbdd21329f3e15eeca6df2d4bc11c04d9d91c0 (diff)
downloadlinux-linaro-stable-d1c8bbd793e4c2f346f8788ad312f5b5b530aff5.tar.gz
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>
Diffstat (limited to 'drivers/spi/spi-sh-hspi.c')
-rw-r--r--drivers/spi/spi-sh-hspi.c364
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 000000000000..8356ec8cfda2
--- /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");