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ramips: improve rt2880 spi setup

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* check clock rate, SPI mode, and word sizes
* setup spi polarity
* enable spi1 hw if need

Signed-off-by: Michael Lee <igvtee@gmail.com>

SVN-Revision: 47577
This commit is contained in:
John Crispin 2015-11-22 11:48:51 +00:00
parent 2ce886f149
commit a58dec6275
1 changed files with 63 additions and 12 deletions
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75
target/linux/ramips/patches-3.18/0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch
View file

@ -41,7 +41,7 @@ Acked-by: John Crispin <blogic@openwrt.org>
spi-s3c24xx-hw-$(CONFIG_SPI_S3C24XX_FIQ) += spi-s3c24xx-fiq.o
--- /dev/null
+++ b/drivers/spi/spi-rt2880.c
@@ -0,0 +1,488 @@
@@ -0,0 +1,539 @@
+/*
+ * spi-rt2880.c -- Ralink RT288x/RT305x SPI controller driver
+ *
@ -175,6 +175,7 @@ Acked-by: John Crispin <blogic@openwrt.org>
+ unsigned int sys_freq;
+ unsigned int speed;
+ u16 wait_loops;
+ u16 mode;
+ struct clk *clk;
+};
+
@ -265,6 +266,17 @@ Acked-by: John Crispin <blogic@openwrt.org>
+ return 0;
+}
+
+static u32 get_arbiter_offset(struct spi_master *master)
+{
+ u32 offset;
+
+ offset = RAMIPS_SPI_ARBITER;
+ if (master->bus_num == 1)
+ offset -= RAMIPS_SPI_DEV_OFFSET;
+
+ return offset;
+}
+
+static void rt2880_spi_set_cs(struct rt2880_spi *rs, int enable)
+{
+ if (enable)
@ -396,21 +408,60 @@ Acked-by: John Crispin <blogic@openwrt.org>
+
+static int rt2880_spi_setup(struct spi_device *spi)
+{
+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
+ struct spi_master *master = spi->master;
+ struct rt2880_spi *rs = spi_master_get_devdata(master);
+ u32 reg, old_reg, arbit_off;
+
+ if ((spi->max_speed_hz == 0) ||
+ (spi->max_speed_hz > (rs->sys_freq / 2)))
+ spi->max_speed_hz = (rs->sys_freq / 2);
+
+ if (spi->max_speed_hz < (rs->sys_freq / 128)) {
+ dev_err(&spi->dev, "setup: requested speed is too low %d Hz\n",
+ spi->max_speed_hz);
+ if ((spi->max_speed_hz > master->max_speed_hz) ||
+ (spi->max_speed_hz < master->min_speed_hz)) {
+ dev_err(&spi->dev, "invalide requested speed %d Hz\n",
+ spi->max_speed_hz);
+ return -EINVAL;
+ }
+
+ /*
+ * baudrate & width will be set rt2880_spi_setup_transfer
+ */
+ if (!(master->bits_per_word_mask &
+ BIT(spi->bits_per_word - 1))) {
+ dev_err(&spi->dev, "invalide bits_per_word %d\n",
+ spi->bits_per_word);
+ return -EINVAL;
+ }
+
+ /* the hardware seems can't work on mode0 force it to mode3 */
+ if ((spi->mode & (SPI_CPOL | SPI_CPHA)) == SPI_MODE_0) {
+ dev_warn(&spi->dev, "force spi mode3\n");
+ spi->mode |= SPI_MODE_3;
+ }
+
+ /* chip polarity */
+ arbit_off = get_arbiter_offset(master);
+ reg = old_reg = rt2880_spi_read(rs, arbit_off);
+ if (spi->mode & SPI_CS_HIGH) {
+ switch (master->bus_num) {
+ case 1:
+ reg |= SPI1_POR;
+ break;
+ default:
+ reg |= SPI0_POR;
+ break;
+ }
+ } else {
+ switch (master->bus_num) {
+ case 1:
+ reg &= ~SPI1_POR;
+ break;
+ default:
+ reg &= ~SPI0_POR;
+ break;
+ }
+ }
+
+ /* enable spi1 */
+ if (master->bus_num == 1)
+ reg |= SPICTL_ARB_EN;
+
+ if (reg != old_reg)
+ rt2880_spi_write(rs, arbit_off, reg);
+
+ return 0;
+}
+