[PATCH 15/15] spi: add locomo SPI driver
Dmitry Eremin-Solenikov
dbaryshkov at gmail.com
Mon Oct 27 17:02:08 PDT 2014
LoCoMo chip has a built-in simple SPI controller. On Sharp SL-5500 PDDAs
it is connected to external MMC slot.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov at gmail.com>
---
drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-locomo.c | 370 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/locomo.h | 30 ++++
4 files changed, 409 insertions(+)
create mode 100644 drivers/spi/spi-locomo.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 84e7c9e..1395780 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -242,6 +242,14 @@ config SPI_LM70_LLP
which interfaces to an LM70 temperature sensor using
a parallel port.
+config SPI_LOCOMO
+ tristate "Locomo SPI master"
+ depends on MFD_LOCOMO
+ select SPI_BITBANG
+ help
+ This enables using the SPI controller as present in the LoCoMo
+ chips. It is probably only usefull on the Sharp SL-5x00 PDA family.
+
config SPI_MPC52xx
tristate "Freescale MPC52xx SPI (non-PSC) controller support"
depends on PPC_MPC52xx
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 78f24ca..4f96197 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_SPI_FSL_SPI) += spi-fsl-spi.o
obj-$(CONFIG_SPI_GPIO) += spi-gpio.o
obj-$(CONFIG_SPI_IMX) += spi-imx.o
obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o
+obj-$(CONFIG_SPI_LOCOMO) += spi-locomo.o
obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mpc512x-psc.o
obj-$(CONFIG_SPI_MPC52xx_PSC) += spi-mpc52xx-psc.o
obj-$(CONFIG_SPI_MPC52xx) += spi-mpc52xx.o
diff --git a/drivers/spi/spi-locomo.c b/drivers/spi/spi-locomo.c
new file mode 100644
index 0000000..8e9e5c4
--- /dev/null
+++ b/drivers/spi/spi-locomo.c
@@ -0,0 +1,370 @@
+/*
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/mfd/locomo.h>
+#include <linux/delay.h>
+
+struct locomospi_dev {
+ struct spi_bitbang bitbang;
+ void __iomem *base;
+ int clock_base;
+ int clock_div;
+
+ u16 save_ct;
+ u16 save_md;
+};
+
+static void locomospi_reg_open(struct locomospi_dev *spidev)
+{
+ u16 r;
+
+ spidev->clock_div = DIV_64;
+ spidev->clock_base = CLOCK_18MHZ;
+ writew(LOCOMO_SPIMD_MSB1ST | LOCOMO_SPIMD_DOSTAT | LOCOMO_SPIMD_RCPOL |
+ LOCOMO_SPIMD_TCPOL | (spidev->clock_base << 3) |
+ spidev->clock_div,
+ spidev->base + LOCOMO_SPIMD);
+
+ /* if (locomospi_carddetect()) { */
+ r = readw(spidev->base + LOCOMO_SPIMD);
+ r |= LOCOMO_SPIMD_XON;
+ writew(r, spidev->base + LOCOMO_SPIMD);
+
+ r = readw(spidev->base + LOCOMO_SPIMD);
+ r |= LOCOMO_SPIMD_XEN;
+ writew(r, spidev->base + LOCOMO_SPIMD);
+ /* } */
+
+ writew(LOCOMO_SPICT_CS, spidev->base + LOCOMO_SPICT);
+
+ r = readw(spidev->base + LOCOMO_SPICT);
+ r |= (LOCOMO_SPICT_CEN | LOCOMO_SPICT_RXUEN | LOCOMO_SPICT_ALIGNEN);
+ writew(r, spidev->base + LOCOMO_SPICT);
+
+ udelay(200);
+
+ r = readw(spidev->base + LOCOMO_SPICT);
+ writew(r, spidev->base + LOCOMO_SPICT);
+
+ r = readw(spidev->base + LOCOMO_SPICT);
+ r &= ~LOCOMO_SPICT_CS;
+ writew(r, spidev->base + LOCOMO_SPICT);
+}
+
+static void locomospi_reg_release(struct locomospi_dev *spidev)
+{
+ u16 r;
+
+ r = readw(spidev->base + LOCOMO_SPICT);
+ r &= ~LOCOMO_SPICT_CEN;
+ writew(r, spidev->base + LOCOMO_SPICT);
+
+ r = readw(spidev->base + LOCOMO_SPIMD);
+ r &= ~LOCOMO_SPIMD_XEN;
+ writew(r, spidev->base + LOCOMO_SPIMD);
+
+ r = readw(spidev->base + LOCOMO_SPIMD);
+ r &= ~LOCOMO_SPIMD_XON;
+ writew(r, spidev->base + LOCOMO_SPIMD);
+
+ r = readw(spidev->base + LOCOMO_SPICT);
+ r |= LOCOMO_SPIMD_XEN; /* FIXME */
+ writew(r, spidev->base + LOCOMO_SPICT);
+}
+
+
+static void locomospi_chipselect(struct spi_device *spi, int is_active)
+{
+ struct locomospi_dev *spidev;
+ u16 r;
+
+ dev_dbg(&spi->dev, "SPI cs: %d\n", is_active);
+
+ spidev = spi_master_get_devdata(spi->master);
+
+ r = readw(spidev->base + LOCOMO_SPICT);
+ if (!!is_active ^ !!(spi->mode & SPI_CS_HIGH))
+ r &= ~LOCOMO_SPICT_CS;
+ else
+ r |= LOCOMO_SPICT_CS;
+ writew(r, spidev->base + LOCOMO_SPICT);
+}
+
+static u32 locomospi_txrx_word(struct spi_device *spi,
+ unsigned nsecs,
+ u32 word, u8 bits)
+{
+ struct locomospi_dev *spidev;
+ int wait;
+ int j;
+ u32 rx;
+
+ spidev = spi_master_get_devdata(spi->master);
+
+ if (spidev->clock_div == 4)
+ wait = 0x10000;
+ else
+ wait = 8;
+
+ for (j = 0; j < wait; j++) {
+ if (readw(spidev->base + LOCOMO_SPIST) & LOCOMO_SPI_RFW)
+ break;
+ }
+
+ writeb(word, spidev->base + LOCOMO_SPITD);
+ ndelay(nsecs);
+
+ for (j = 0; j < wait; j++) {
+ if (readw(spidev->base + LOCOMO_SPIST) & LOCOMO_SPI_RFR)
+ break;
+ }
+
+ rx = readb(spidev->base + LOCOMO_SPIRD);
+ ndelay(nsecs);
+
+ dev_dbg(&spi->dev, "SPI txrx: %02x/%02x\n", word, rx);
+
+ return rx;
+}
+
+static void locomo_spi_set_speed(struct locomospi_dev *spidev, u32 hz)
+{
+ u16 r;
+
+ if (hz >= 24576000) {
+ spidev->clock_base = CLOCK_25MHZ;
+ spidev->clock_div = DIV_1;
+ } else if (hz >= 22579200) {
+ spidev->clock_base = CLOCK_22MHZ;
+ spidev->clock_div = DIV_1;
+ } else if (hz >= 18432000) {
+ spidev->clock_base = CLOCK_18MHZ;
+ spidev->clock_div = DIV_1;
+ } else if (hz >= 12288000) {
+ spidev->clock_base = CLOCK_25MHZ;
+ spidev->clock_div = DIV_2;
+ } else if (hz >= 11289600) {
+ spidev->clock_base = CLOCK_22MHZ;
+ spidev->clock_div = DIV_2;
+ } else if (hz >= 9216000) {
+ spidev->clock_base = CLOCK_18MHZ;
+ spidev->clock_div = DIV_2;
+ } else if (hz >= 6144000) {
+ spidev->clock_base = CLOCK_25MHZ;
+ spidev->clock_div = DIV_4;
+ } else if (hz >= 5644800) {
+ spidev->clock_base = CLOCK_22MHZ;
+ spidev->clock_div = DIV_4;
+ } else if (hz >= 4608000) {
+ spidev->clock_base = CLOCK_18MHZ;
+ spidev->clock_div = DIV_4;
+ } else if (hz >= 3072000) {
+ spidev->clock_base = CLOCK_25MHZ;
+ spidev->clock_div = DIV_8;
+ } else if (hz >= 2822400) {
+ spidev->clock_base = CLOCK_22MHZ;
+ spidev->clock_div = DIV_8;
+ } else if (hz >= 2304000) {
+ spidev->clock_base = CLOCK_18MHZ;
+ spidev->clock_div = DIV_8;
+ } else if (hz >= 384000) {
+ spidev->clock_base = CLOCK_25MHZ;
+ spidev->clock_div = DIV_64;
+ } else if (hz >= 352800) {
+ spidev->clock_base = CLOCK_22MHZ;
+ spidev->clock_div = DIV_64;
+ } else { /* set to 288 Khz */
+ spidev->clock_base = CLOCK_18MHZ;
+ spidev->clock_div = DIV_64;
+ }
+
+ r = readw(spidev->base + LOCOMO_SPIMD);
+ if ((r & LOCOMO_SPIMD_CLKSEL) == spidev->clock_div &&
+ (r & LOCOMO_SPIMD_XSEL) == (spidev->clock_div << 3))
+ return;
+
+ r &= ~(LOCOMO_SPIMD_XSEL | LOCOMO_SPIMD_CLKSEL | LOCOMO_SPIMD_XEN);
+ writew(r, spidev->base + LOCOMO_SPIMD);
+
+ r |= (spidev->clock_div | (spidev->clock_base << 3) | LOCOMO_SPIMD_XEN);
+ writew(r, spidev->base + LOCOMO_SPIMD);
+
+ udelay(300);
+}
+
+static int locomo_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct locomospi_dev *spidev;
+ u16 r;
+ u32 hz = 0;
+ int rc = spi_bitbang_setup_transfer(spi, t);
+
+ if (rc)
+ return rc;
+
+ if (t)
+ hz = t->speed_hz;
+ if (!hz)
+ hz = spi->max_speed_hz;
+
+ spidev = spi_master_get_devdata(spi->master);
+
+ r = readw(spidev->base + LOCOMO_SPIMD);
+ if (hz == 0) {
+ r &= ~LOCOMO_SPIMD_XON;
+ writew(r, spidev->base + LOCOMO_SPIMD);
+ } else {
+ r |= LOCOMO_SPIMD_XON;
+ writew(r, spidev->base + LOCOMO_SPIMD);
+ locomo_spi_set_speed(spidev, hz);
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int locomo_spi_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct locomospi_dev *spidev = spi_master_get_devdata(master);
+ int ret;
+
+ /* Stop the queue running */
+ ret = spi_master_suspend(master);
+ if (ret) {
+ dev_warn(dev, "cannot suspend master\n");
+ return ret;
+ }
+
+ spidev->save_ct = readw(spidev->base + LOCOMO_SPICT);
+ writew(0x40, spidev->base + LOCOMO_SPICT);
+
+ spidev->save_md = readw(spidev->base + LOCOMO_SPIMD);
+ writew(0x3c14, spidev->base + LOCOMO_SPIMD);
+
+ return 0;
+}
+
+static int locomo_spi_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct locomospi_dev *spidev = spi_master_get_devdata(master);
+ int ret;
+
+ writew(spidev->save_ct, spidev->base + LOCOMO_SPICT);
+ writew(spidev->save_md, spidev->base + LOCOMO_SPIMD);
+
+ /* Start the queue running */
+ ret = spi_master_resume(master);
+ if (ret)
+ dev_err(dev, "problem starting queue (%d)\n", ret);
+
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(locomo_spi_pm_ops,
+ locomo_spi_suspend, locomo_spi_resume);
+
+#define LOCOMO_SPI_PM_OPS (&locomo_spi_pm_ops)
+#else
+#define LOCOMO_SPI_PM_OPS NULL
+#endif
+
+static int locomo_spi_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct spi_master *master;
+ struct locomospi_dev *spidev;
+ int ret;
+
+ dev_info(&pdev->dev, "LoCoO SPI Driver\n");
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct locomospi_dev));
+ if (!master)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, master);
+
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 8);
+ master->bus_num = 0;
+ master->num_chipselect = 1;
+
+ spidev = spi_master_get_devdata(master);
+ spidev->bitbang.master = spi_master_get(master);
+
+ spidev->bitbang.setup_transfer = locomo_spi_setup_transfer;
+ spidev->bitbang.chipselect = locomospi_chipselect;
+ spidev->bitbang.txrx_word[SPI_MODE_0] = locomospi_txrx_word;
+ spidev->bitbang.txrx_word[SPI_MODE_1] = locomospi_txrx_word;
+ spidev->bitbang.txrx_word[SPI_MODE_2] = locomospi_txrx_word;
+ spidev->bitbang.txrx_word[SPI_MODE_3] = locomospi_txrx_word;
+
+ spidev->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+ spidev->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(spidev->base)) {
+ ret = PTR_ERR(spidev->base);
+ goto out_put;
+ }
+
+ locomospi_reg_open(spidev);
+
+ ret = spi_bitbang_start(&spidev->bitbang);
+ if (ret) {
+ dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
+ goto out_put;
+ }
+
+ return 0;
+
+out_put:
+ spi_master_put(master);
+ return ret;
+}
+
+static int locomo_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct locomospi_dev *spidev = spi_master_get_devdata(master);
+
+ spi_bitbang_stop(&spidev->bitbang);
+ locomospi_reg_release(spidev);
+ spi_master_put(master);
+
+
+ return 0;
+}
+
+static struct platform_driver locomo_spi_driver = {
+ .probe = locomo_spi_probe,
+ .remove = locomo_spi_remove,
+ .driver = {
+ .name = "locomo-spi",
+ .owner = THIS_MODULE,
+ .pm = LOCOMO_SPI_PM_OPS,
+ },
+};
+module_platform_driver(locomo_spi_driver);
+
+MODULE_AUTHOR("Thomas Kunze thommy at tabao.de");
+MODULE_DESCRIPTION("LoCoMo SPI driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:locomo-spi");
diff --git a/include/linux/mfd/locomo.h b/include/linux/mfd/locomo.h
index 1f54300..f822d77 100644
--- a/include/linux/mfd/locomo.h
+++ b/include/linux/mfd/locomo.h
@@ -53,7 +53,37 @@
/* SPI interface */
#define LOCOMO_SPI 0x60
#define LOCOMO_SPIMD 0x00 /* SPI mode setting */
+#define LOCOMO_SPIMD_LOOPBACK (1 << 15) /* loopback tx to rx */
+#define LOCOMO_SPIMD_MSB1ST (1 << 14) /* send MSB first */
+#define LOCOMO_SPIMD_DOSTAT (1 << 13) /* transmit line is idle high */
+#define LOCOMO_SPIMD_TCPOL (1 << 11) /* transmit CPOL (maybe affects CPHA too) */
+#define LOCOMO_SPIMD_RCPOL (1 << 10) /* receive CPOL (maybe affects CPHA too) */
+#define LOCOMO_SPIMD_TDINV (1 << 9) /* invert transmit line */
+#define LOCOMO_SPIMD_RDINV (1 << 8) /* invert receive line */
+#define LOCOMO_SPIMD_XON (1 << 7) /* enable spi controller clock */
+#define LOCOMO_SPIMD_XEN (1 << 6) /* clock bit write enable xon must be off, wait 300 us before xon->1 */
+#define LOCOMO_SPIMD_XSEL 0x0018 /* clock select */
+#define CLOCK_18MHZ 0 /* 18,432 MHz clock */
+#define CLOCK_22MHZ 1 /* 22,5792 MHz clock */
+#define CLOCK_25MHZ 2 /* 24,576 MHz clock */
+#define LOCOMO_SPIMD_CLKSEL 0x7
+#define DIV_1 0 /* don't divide clock */
+#define DIV_2 1 /* divide clock by two */
+#define DIV_4 2 /* divide clock by four */
+#define DIV_8 3 /* divide clock by eight*/
+#define DIV_64 4 /* divide clock by 64 */
+
#define LOCOMO_SPICT 0x04 /* SPI mode control */
+#define LOCOMO_SPICT_CRC16_7_B (1 << 15) /* 0: crc16 1: crc7 */
+#define LOCOMO_SPICT_CRCRX_TX_B (1 << 14)
+#define LOCOMO_SPICT_CRCRESET_B (1 << 13)
+#define LOCOMO_SPICT_CEN (1 << 7) /* ?? enable */
+#define LOCOMO_SPICT_CS (1 << 6) /* chip select */
+#define LOCOMO_SPICT_UNIT16 (1 << 5) /* 0: 8 bit units, 1: 16 bit unit */
+#define LOCOMO_SPICT_ALIGNEN (1 << 2) /* align transfer enable */
+#define LOCOMO_SPICT_RXWEN (1 << 1) /* continous receive */
+#define LOCOMO_SPICT_RXUEN (1 << 0) /* aligned receive */
+
#define LOCOMO_SPIST 0x08 /* SPI status */
#define LOCOMO_SPI_TEND (1 << 3) /* Transfer end bit */
#define LOCOMO_SPI_REND (1 << 2) /* Receive end bit */
--
2.1.1
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