summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-sh-hspi.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/spi/spi-sh-hspi.c')
-rw-r--r--drivers/spi/spi-sh-hspi.c331
1 files changed, 331 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..934138c7b3d3
--- /dev/null
+++ b/drivers/spi/spi-sh-hspi.c
@@ -0,0 +1,331 @@
+/*
+ * 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/clk.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/delay.h>
+#include <linux/list.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 device *dev;
+ struct clk *clk;
+};
+
+/*
+ * 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;
+}
+
+/*
+ * spi master function
+ */
+static int hspi_prepare_transfer(struct spi_master *master)
+{
+ struct hspi_priv *hspi = spi_master_get_devdata(master);
+
+ pm_runtime_get_sync(hspi->dev);
+ return 0;
+}
+
+static int hspi_unprepare_transfer(struct spi_master *master)
+{
+ struct hspi_priv *hspi = spi_master_get_devdata(master);
+
+ pm_runtime_put_sync(hspi->dev);
+ return 0;
+}
+
+static void hspi_hw_setup(struct hspi_priv *hspi,
+ struct spi_message *msg,
+ struct spi_transfer *t)
+{
+ struct spi_device *spi = msg->spi;
+ struct device *dev = hspi->dev;
+ u32 target_rate;
+ u32 spcr, idiv_clk;
+ u32 rate, best_rate, min, tmp;
+
+ target_rate = t ? t->speed_hz : 0;
+ if (!target_rate)
+ target_rate = spi->max_speed_hz;
+
+ /*
+ * find best IDIV/CLKCx settings
+ */
+ min = ~0;
+ best_rate = 0;
+ spcr = 0;
+ for (idiv_clk = 0x00; idiv_clk <= 0x3F; idiv_clk++) {
+ rate = clk_get_rate(hspi->clk);
+
+ /* IDIV calculation */
+ if (idiv_clk & (1 << 5))
+ rate /= 128;
+ else
+ rate /= 16;
+
+ /* CLKCx calculation */
+ rate /= (((idiv_clk & 0x1F) + 1) * 2) ;
+
+ /* save best settings */
+ tmp = abs(target_rate - rate);
+ if (tmp < min) {
+ min = tmp;
+ spcr = idiv_clk;
+ best_rate = rate;
+ }
+ }
+
+ if (spi->mode & SPI_CPHA)
+ spcr |= 1 << 7;
+ if (spi->mode & SPI_CPOL)
+ spcr |= 1 << 6;
+
+ dev_dbg(dev, "speed %d/%d\n", target_rate, best_rate);
+
+ hspi_write(hspi, SPCR, spcr);
+ hspi_write(hspi, SPSR, 0x0);
+ hspi_write(hspi, SPSCR, 0x1); /* master mode */
+}
+
+static int hspi_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct hspi_priv *hspi = spi_master_get_devdata(master);
+ struct spi_transfer *t;
+ u32 tx;
+ u32 rx;
+ int ret, i;
+
+ dev_dbg(hspi->dev, "%s\n", __func__);
+
+ ret = 0;
+ list_for_each_entry(t, &msg->transfers, transfer_list) {
+ hspi_hw_setup(hspi, msg, t);
+
+ for (i = 0; i < t->len; i++) {
+
+ /* wait remains */
+ ret = hspi_status_check_timeout(hspi, 0x1, 0);
+ if (ret < 0)
+ break;
+
+ tx = 0;
+ if (t->tx_buf)
+ tx = (u32)((u8 *)t->tx_buf)[i];
+
+ hspi_write(hspi, SPTBR, tx);
+
+ /* wait recive */
+ ret = hspi_status_check_timeout(hspi, 0x4, 0x4);
+ if (ret < 0)
+ break;
+
+ rx = hspi_read(hspi, SPRBR);
+ if (t->rx_buf)
+ ((u8 *)t->rx_buf)[i] = (u8)rx;
+
+ }
+
+ msg->actual_length += t->len;
+ }
+
+ msg->status = ret;
+ spi_finalize_current_message(master);
+
+ return ret;
+}
+
+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 __devinit hspi_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct spi_master *master;
+ struct hspi_priv *hspi;
+ struct clk *clk;
+ 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;
+ }
+
+ clk = clk_get(NULL, "shyway_clk");
+ if (!clk) {
+ dev_err(&pdev->dev, "shyway_clk is required\n");
+ ret = -EINVAL;
+ goto error0;
+ }
+
+ hspi = spi_master_get_devdata(master);
+ dev_set_drvdata(&pdev->dev, hspi);
+
+ /* init hspi */
+ hspi->master = master;
+ hspi->dev = &pdev->dev;
+ hspi->clk = clk;
+ 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;
+ }
+
+ master->num_chipselect = 1;
+ master->bus_num = pdev->id;
+ master->setup = hspi_setup;
+ master->cleanup = hspi_cleanup;
+ master->mode_bits = SPI_CPOL | SPI_CPHA;
+ master->prepare_transfer_hardware = hspi_prepare_transfer;
+ master->transfer_one_message = hspi_transfer_one_message;
+ master->unprepare_transfer_hardware = hspi_unprepare_transfer;
+ ret = spi_register_master(master);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "spi_register_master error.\n");
+ goto error2;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+
+ dev_info(&pdev->dev, "probed\n");
+
+ return 0;
+
+ error2:
+ devm_iounmap(hspi->dev, hspi->addr);
+ error1:
+ clk_put(clk);
+ error0:
+ 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);
+
+ clk_put(hspi->clk);
+ spi_unregister_master(hspi->master);
+ 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");