[OpenWrt-Devel] [PATCH 6/8] ramips: improve mt7621 spi chip select
John Crispin
blogic at openwrt.org
Wed Oct 14 00:24:21 EDT 2015
2 comments inline
On 11/10/2015 05:54, Michael Lee wrote:
> * 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));
> ++}
this is an unrelated part in the patch.
> ++
> ++/* 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;
i dont think you really want to remove that line.
> +
> + 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");
>
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