[OpenWrt-Devel] [PATCH 6/8] ramips: improve mt7621 spi chip select

Michael Lee igvtee at gmail.com
Sat Oct 10 23:54:32 EDT 2015


* use chip select register to control chip select function instead of
  use chip select polarity
* should support use gpio as cs pin
* deselected the spi device when setup and add debug info

Signed-off-by: Michael Lee <igvtee at gmail.com>
---
 ...0061-SPI-ralink-add-mt7621-SoC-spi-driver.patch | 95 ++++++++++++++++------
 1 file changed, 68 insertions(+), 27 deletions(-)

diff --git a/target/linux/ramips/patches-3.18/0061-SPI-ralink-add-mt7621-SoC-spi-driver.patch b/target/linux/ramips/patches-3.18/0061-SPI-ralink-add-mt7621-SoC-spi-driver.patch
index d1067ea..1b2476c 100644
--- a/target/linux/ramips/patches-3.18/0061-SPI-ralink-add-mt7621-SoC-spi-driver.patch
+++ b/target/linux/ramips/patches-3.18/0061-SPI-ralink-add-mt7621-SoC-spi-driver.patch
@@ -25,7 +25,7 @@
  obj-$(CONFIG_SPI_OC_TINY)		+= spi-oc-tiny.o
 --- /dev/null
 +++ b/drivers/spi/spi-mt7621.c
-@@ -0,0 +1,582 @@
+@@ -0,0 +1,623 @@
 +/*
 + * spi-mt7621.c -- MediaTek MT7621 SPI controller driver
 + *
@@ -53,6 +53,7 @@
 +#include <linux/of_device.h>
 +#include <linux/platform_device.h>
 +#include <linux/swab.h>
++#include <linux/gpio.h>
 +
 +#include <ralink_regs.h>
 +
@@ -208,30 +209,26 @@
 +	return (prescale << SPIMASTER_CLKSEL_OFFSET);
 +}
 +
-+static void mt7621_spi_reset(struct mt7621_spi *rs, int duplex)
++static void mt7621_spi_set_cs(struct spi_device *spi, bool enable)
 +{
-+	u32 master = mt7621_spi_read(rs, MT7621_SPI_MASTER);
-+
-+	master |= 7 << 29;
-+	master |= 1 << 2;
-+	if (duplex)
-+		master |= 1 << 10;
-+	else
-+		master &= ~(1 << 10);
++	struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
++	u32 reg;
 +
-+	mt7621_spi_write(rs, MT7621_SPI_MASTER, master);
-+}
++	if (spi->mode & SPI_CS_HIGH)
++		enable = !enable;
++	enable = !enable;
 +
-+static void mt7621_spi_set_cs(struct spi_device *spi, int enable)
-+{
-+	struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
-+	int cs = spi->chip_select;
-+	u32 polar = 0;
++	reg = mt7621_spi_read(rs, MT7621_SPI_MASTER);
++	reg &= ~(SPIMASTER_CS_MASK << SPIMASTER_CS_OFFSET);
 +
-+        mt7621_spi_reset(rs, cs);
 +	if (enable)
-+		polar = BIT(cs);
-+	mt7621_spi_write(rs, MT7621_SPI_POLAR, polar);
++		reg |= (spi->chip_select << SPIMASTER_CS_OFFSET);
++	else {
++		/* when disable just enable cs 8 instead */
++		reg |= (SPIMASTER_CS_MASK << SPIMASTER_CS_OFFSET);
++	}
++
++	mt7621_spi_write(rs, MT7621_SPI_MASTER, reg);
 +}
 +
 +static inline int mt7621_spi_wait_ready(struct mt7621_spi *rs, int len)
@@ -247,6 +244,47 @@
 +	return -ETIMEDOUT;
 +}
 +
++static void mt7621_dump_reg(struct spi_master *master, const char *func)
++{
++	struct mt7621_spi *rs = spi_master_get_devdata(master);
++
++	dev_dbg(&master->dev, "%s trans: %08x, opcode: %08x, data0: %08x, "
++			"data1: %08x, data2: %08x, data3: %08x, " \
++			"data4: %08x, data5: %08x, data6: %08x, " \
++			"data7: %08x, master: %08x, morebuf: %08x, " \
++			"qctl: %08x, status: %08x, polar: %08x, " \
++			"space: %08x\n",
++			func,
++			mt7621_spi_read(rs, MT7621_SPI_TRANS),
++			mt7621_spi_read(rs, MT7621_SPI_OPCODE),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0 + 4),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0 + 8),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0 + 12),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0 + 16),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0 + 20),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0 + 24),
++			mt7621_spi_read(rs, MT7621_SPI_DATA0 + 28),
++			mt7621_spi_read(rs, MT7621_SPI_MASTER),
++			mt7621_spi_read(rs, MT7621_SPI_MOREBUF),
++			mt7621_spi_read(rs, MT7621_SPI_QUEUE_CTL),
++			mt7621_spi_read(rs, MT7621_SPI_STATUS),
++			mt7621_spi_read(rs, MT7621_SPI_POLAR),
++			mt7621_spi_read(rs, MT7621_SPI_SPACE));
++}
++
++/* copy from spi.c */
++static void spi_set_cs(struct spi_device *spi, bool enable)
++{
++	if (spi->mode & SPI_CS_HIGH)
++		enable = !enable;
++
++	if (spi->cs_gpio >= 0)
++		gpio_set_value(spi->cs_gpio, !enable);
++	else if (spi->master->set_cs)
++		spi->master->set_cs(spi, !enable);
++}
++
 +static int mt7621_spi_transfer_half_duplex(struct spi_master *master,
 +					   struct spi_message *m)
 +{
@@ -297,7 +335,7 @@
 +	val |= (rx_len * 8) << 12;
 +	mt7621_spi_write(rs, MT7621_SPI_MOREBUF, val);
 +
-+	mt7621_spi_set_cs(spi, 1);
++	spi_set_cs(spi, true);
 +
 +	val = mt7621_spi_read(rs, MT7621_SPI_TRANS);
 +	val |= SPITRANS_START;
@@ -305,7 +343,7 @@
 +
 +	mt7621_spi_wait_ready(rs, 36);
 +
-+	mt7621_spi_set_cs(spi, 0);
++	spi_set_cs(spi, false);
 +
 +	for (i = 0; i < rx_len; i += 4)
 +		data[i / 4] = mt7621_spi_read(rs, MT7621_SPI_DATA0 + i);
@@ -377,7 +415,7 @@
 +	val |= (rx_len * 8) << 12;
 +	mt7621_spi_write(rs, MT7621_SPI_MOREBUF, val);
 +
-+	mt7621_spi_set_cs(spi, 1);
++	spi_set_cs(spi, true);
 +
 +	val = mt7621_spi_read(rs, MT7621_SPI_TRANS);
 +	val |= SPITRANS_START;
@@ -385,7 +423,7 @@
 +
 +	mt7621_spi_wait_ready(rs, 36);
 +
-+	mt7621_spi_set_cs(spi, 0);
++	spi_set_cs(spi, false);
 +
 +	for (i = 0; i < rx_len; i += 4)
 +		data[i / 4] = mt7621_spi_read(rs, MT7621_SPI_DATA4 + i);
@@ -451,6 +489,11 @@
 +	/* enable more buffer mode */
 +	mt7621_spi_setbits(rs, MT7621_SPI_MASTER, SPIMASTER_MB_MODE);
 +
++	/* deselected the spi device */
++	spi_set_cs(spi, false);
++
++	mt7621_dump_reg(master, __func__);
++
 +	return 0;
 +}
 +
@@ -547,8 +590,8 @@
 +	master->flags = SPI_MASTER_HALF_DUPLEX;
 +	master->setup = mt7621_spi_setup;
 +	master->prepare_message = mt7621_spi_prepare_message;
++	master->set_cs = mt7621_spi_set_cs;
 +	master->transfer_one_message = mt7621_spi_transfer_one_message;
-+	master->num_chipselect = 2;
 +
 +	dev_set_drvdata(&pdev->dev, master);
 +
@@ -559,8 +602,6 @@
 +
 +	device_reset(&pdev->dev);
 +
-+	mt7621_spi_reset(rs, 0);
-+
 +	ret = devm_spi_register_master(&pdev->dev, master);
 +	if (ret < 0) {
 +		dev_err(&pdev->dev, "devm_spi_register_master error.\n");
-- 
2.3.6
_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel



More information about the openwrt-devel mailing list