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-rw-r--r--drivers/spi/spi-sh-hspi.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/drivers/spi/spi-sh-hspi.c b/drivers/spi/spi-sh-hspi.c
new file mode 100644
index 000000000..a62034e2a
--- /dev/null
+++ b/drivers/spi/spi-sh-hspi.c
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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
+ */
+
+#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)
+
+struct hspi_priv {
+ void __iomem *addr;
+ struct spi_controller *ctlr;
+ 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);
+}
+
+static void hspi_bit_set(struct hspi_priv *hspi, int reg, u32 mask, u32 set)
+{
+ u32 val = hspi_read(hspi, reg);
+
+ val &= ~mask;
+ val |= set & mask;
+
+ hspi_write(hspi, reg, val);
+}
+
+/*
+ * 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;
+
+ udelay(10);
+ }
+
+ dev_err(hspi->dev, "timeout\n");
+ return -ETIMEDOUT;
+}
+
+/*
+ * spi master function
+ */
+
+#define hspi_hw_cs_enable(hspi) hspi_hw_cs_ctrl(hspi, 0)
+#define hspi_hw_cs_disable(hspi) hspi_hw_cs_ctrl(hspi, 1)
+static void hspi_hw_cs_ctrl(struct hspi_priv *hspi, int hi)
+{
+ hspi_bit_set(hspi, SPSCR, (1 << 6), (hi) << 6);
+}
+
+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 spcr, idiv_clk;
+ u32 rate, best_rate, min, tmp;
+
+ /*
+ * 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(t->speed_hz - 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", t->speed_hz, best_rate);
+
+ hspi_write(hspi, SPCR, spcr);
+ hspi_write(hspi, SPSR, 0x0);
+ hspi_write(hspi, SPSCR, 0x21); /* master mode / CS control */
+}
+
+static int hspi_transfer_one_message(struct spi_controller *ctlr,
+ struct spi_message *msg)
+{
+ struct hspi_priv *hspi = spi_controller_get_devdata(ctlr);
+ struct spi_transfer *t;
+ u32 tx;
+ u32 rx;
+ int ret, i;
+ unsigned int cs_change;
+ const int nsecs = 50;
+
+ dev_dbg(hspi->dev, "%s\n", __func__);
+
+ cs_change = 1;
+ ret = 0;
+ list_for_each_entry(t, &msg->transfers, transfer_list) {
+
+ if (cs_change) {
+ hspi_hw_setup(hspi, msg, t);
+ hspi_hw_cs_enable(hspi);
+ ndelay(nsecs);
+ }
+ cs_change = t->cs_change;
+
+ 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 receive */
+ 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;
+
+ spi_transfer_delay_exec(t);
+
+ if (cs_change) {
+ ndelay(nsecs);
+ hspi_hw_cs_disable(hspi);
+ ndelay(nsecs);
+ }
+ }
+
+ msg->status = ret;
+ if (!cs_change) {
+ ndelay(nsecs);
+ hspi_hw_cs_disable(hspi);
+ }
+ spi_finalize_current_message(ctlr);
+
+ return ret;
+}
+
+static int hspi_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct spi_controller *ctlr;
+ 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;
+ }
+
+ ctlr = spi_alloc_master(&pdev->dev, sizeof(*hspi));
+ if (!ctlr)
+ return -ENOMEM;
+
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "couldn't get clock\n");
+ ret = -EINVAL;
+ goto error0;
+ }
+
+ hspi = spi_controller_get_devdata(ctlr);
+ platform_set_drvdata(pdev, hspi);
+
+ /* init hspi */
+ hspi->ctlr = ctlr;
+ hspi->dev = &pdev->dev;
+ hspi->clk = clk;
+ hspi->addr = devm_ioremap(hspi->dev,
+ res->start, resource_size(res));
+ if (!hspi->addr) {
+ ret = -ENOMEM;
+ goto error1;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+
+ ctlr->bus_num = pdev->id;
+ ctlr->mode_bits = SPI_CPOL | SPI_CPHA;
+ ctlr->dev.of_node = pdev->dev.of_node;
+ ctlr->auto_runtime_pm = true;
+ ctlr->transfer_one_message = hspi_transfer_one_message;
+ ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
+
+ ret = devm_spi_register_controller(&pdev->dev, ctlr);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "devm_spi_register_controller error.\n");
+ goto error2;
+ }
+
+ return 0;
+
+ error2:
+ pm_runtime_disable(&pdev->dev);
+ error1:
+ clk_put(clk);
+ error0:
+ spi_controller_put(ctlr);
+
+ return ret;
+}
+
+static int hspi_remove(struct platform_device *pdev)
+{
+ struct hspi_priv *hspi = platform_get_drvdata(pdev);
+
+ pm_runtime_disable(&pdev->dev);
+
+ clk_put(hspi->clk);
+
+ return 0;
+}
+
+static const struct of_device_id hspi_of_match[] = {
+ { .compatible = "renesas,hspi", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, hspi_of_match);
+
+static struct platform_driver hspi_driver = {
+ .probe = hspi_probe,
+ .remove = hspi_remove,
+ .driver = {
+ .name = "sh-hspi",
+ .of_match_table = hspi_of_match,
+ },
+};
+module_platform_driver(hspi_driver);
+
+MODULE_DESCRIPTION("SuperH HSPI bus driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
+MODULE_ALIAS("platform:sh-hspi");