diff options
| author | John Crispin <john@openwrt.org> | 2015-11-22 11:48:34 +0000 |
|---|---|---|
| committer | John Crispin <john@openwrt.org> | 2015-11-22 11:48:34 +0000 |
| commit | bf89d139e1cf6029eeab39bd06f8ad2f5bc1c739 (patch) | |
| tree | 076a75fba9ab05b1830cb23765f6b3c2b6f36542 | |
| parent | 702c480dfe557087a1d4c534036fee4d59677f38 (diff) | |
| download | upstream-bf89d139e1cf6029eeab39bd06f8ad2f5bc1c739.tar.gz upstream-bf89d139e1cf6029eeab39bd06f8ad2f5bc1c739.tar.bz2 upstream-bf89d139e1cf6029eeab39bd06f8ad2f5bc1c739.zip | |
ramips: improve rt2880 spi wait ready function
use loops_per_jiffy, spi clock speed and write bytes to get the
spi loop count. if loop to 0 than spi operation timeout.
remove usleep. we only write 1 byte to spi device. use busy loop
would be better.
Signed-off-by: Michael Lee <igvtee@gmail.com>
SVN-Revision: 47575
| -rw-r--r-- | target/linux/ramips/patches-3.18/0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch | 31 |
1 files changed, 15 insertions, 16 deletions
diff --git a/target/linux/ramips/patches-3.18/0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch b/target/linux/ramips/patches-3.18/0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch index d6a462c586..00fdeedb87 100644 --- a/target/linux/ramips/patches-3.18/0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch +++ b/target/linux/ramips/patches-3.18/0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch @@ -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 +1,480 @@ +@@ -0,0 +1,479 @@ +/* + * spi-rt2880.c -- Ralink RT288x/RT305x SPI controller driver + * @@ -70,8 +70,6 @@ Acked-by: John Crispin <blogic@openwrt.org> +#define DRIVER_NAME "spi-rt2880" +/* only one slave is supported*/ +#define RALINK_NUM_CHIPSELECTS 1 -+/* in usec */ -+#define RALINK_SPI_WAIT_MAX_LOOP 2000 + +#define RAMIPS_SPI_STAT 0x00 +#define RAMIPS_SPI_CFG 0x10 @@ -173,6 +171,7 @@ Acked-by: John Crispin <blogic@openwrt.org> + void __iomem *base; + unsigned int sys_freq; + unsigned int speed; ++ u16 wait_loops; + struct clk *clk; +}; + @@ -238,6 +237,11 @@ Acked-by: John Crispin <blogic@openwrt.org> + reg = rt2880_spi_read(rs, RAMIPS_SPI_CFG); + reg = ((reg & ~SPICFG_SPICLK_PRESCALE_MASK) | prescale); + rt2880_spi_write(rs, RAMIPS_SPI_CFG, reg); ++ ++ /* some tolerance. double and add 100 */ ++ rs->wait_loops = (8 * HZ * loops_per_jiffy) / ++ (clk_get_rate(rs->clk) / rate); ++ rs->wait_loops = (rs->wait_loops << 1) + 100; + rs->speed = speed; + return 0; +} @@ -273,20 +277,15 @@ Acked-by: John Crispin <blogic@openwrt.org> + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA); +} + -+static inline int rt2880_spi_wait_till_ready(struct rt2880_spi *rs) ++static int rt2880_spi_wait_ready(struct rt2880_spi *rs, int len) +{ -+ int i; -+ -+ for (i = 0; i < RALINK_SPI_WAIT_MAX_LOOP; i++) { -+ u32 status; -+ -+ status = rt2880_spi_read(rs, RAMIPS_SPI_STAT); -+ if ((status & SPISTAT_BUSY) == 0) -+ return 0; ++ int loop = rs->wait_loops * len; + ++ while ((rt2880_spi_read(rs, RAMIPS_SPI_STAT) & SPISTAT_BUSY) && --loop) + cpu_relax(); -+ udelay(1); -+ } ++ ++ if (loop) ++ return 0; + + return -ETIMEDOUT; +} @@ -308,7 +307,7 @@ Acked-by: John Crispin <blogic@openwrt.org> + for (count = 0; count < xfer->len; count++) { + rt2880_spi_write(rs, RAMIPS_SPI_DATA, tx[count]); + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR); -+ err = rt2880_spi_wait_till_ready(rs); ++ err = rt2880_spi_wait_ready(rs, 1); + if (err) { + dev_err(&spi->dev, "TX failed, err=%d\n", err); + goto out; @@ -319,7 +318,7 @@ Acked-by: John Crispin <blogic@openwrt.org> + if (rx) { + for (count = 0; count < xfer->len; count++) { + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTRD); -+ err = rt2880_spi_wait_till_ready(rs); ++ err = rt2880_spi_wait_ready(rs, 1); + if (err) { + dev_err(&spi->dev, "RX failed, err=%d\n", err); + goto out; |