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author | Dave Airlie <airlied@redhat.com> | 2015-04-20 11:32:26 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2015-04-20 13:05:20 +1000 |
commit | 2c33ce009ca2389dbf0535d0672214d09738e35e (patch) | |
tree | 6186a6458c3c160385d794a23eaf07c786a9e61b /drivers/spi/spi-fsl-dspi.c | |
parent | cec32a47010647e8b0603726ebb75b990a4057a4 (diff) | |
parent | 09d51602cf84a1264946711dd4ea0dddbac599a1 (diff) | |
download | linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.tar.gz linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.tar.bz2 linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.zip |
Merge Linus master into drm-next
The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.
I've included the patch into the merge to fix the build.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/spi/spi-fsl-dspi.c')
-rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 97 |
1 files changed, 81 insertions, 16 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index d1a39249704a..5fe54cda309f 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -20,6 +20,7 @@ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> +#include <linux/math64.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> @@ -29,6 +30,7 @@ #include <linux/sched.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> +#include <linux/time.h> #define DRIVER_NAME "fsl-dspi" @@ -51,7 +53,7 @@ #define SPI_CTAR_CPOL(x) ((x) << 26) #define SPI_CTAR_CPHA(x) ((x) << 25) #define SPI_CTAR_LSBFE(x) ((x) << 24) -#define SPI_CTAR_PCSSCR(x) (((x) & 0x00000003) << 22) +#define SPI_CTAR_PCSSCK(x) (((x) & 0x00000003) << 22) #define SPI_CTAR_PASC(x) (((x) & 0x00000003) << 20) #define SPI_CTAR_PDT(x) (((x) & 0x00000003) << 18) #define SPI_CTAR_PBR(x) (((x) & 0x00000003) << 16) @@ -59,6 +61,7 @@ #define SPI_CTAR_ASC(x) (((x) & 0x0000000f) << 8) #define SPI_CTAR_DT(x) (((x) & 0x0000000f) << 4) #define SPI_CTAR_BR(x) ((x) & 0x0000000f) +#define SPI_CTAR_SCALE_BITS 0xf #define SPI_CTAR0_SLAVE 0x0c @@ -148,23 +151,66 @@ static void hz_to_spi_baud(char *pbr, char *br, int speed_hz, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768 }; - int temp, i = 0, j = 0; + int scale_needed, scale, minscale = INT_MAX; + int i, j; + + scale_needed = clkrate / speed_hz; + if (clkrate % speed_hz) + scale_needed++; + + for (i = 0; i < ARRAY_SIZE(brs); i++) + for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) { + scale = brs[i] * pbr_tbl[j]; + if (scale >= scale_needed) { + if (scale < minscale) { + minscale = scale; + *br = i; + *pbr = j; + } + break; + } + } - temp = clkrate / 2 / speed_hz; + if (minscale == INT_MAX) { + pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n", + speed_hz, clkrate); + *pbr = ARRAY_SIZE(pbr_tbl) - 1; + *br = ARRAY_SIZE(brs) - 1; + } +} - for (i = 0; i < ARRAY_SIZE(pbr_tbl); i++) - for (j = 0; j < ARRAY_SIZE(brs); j++) { - if (pbr_tbl[i] * brs[j] >= temp) { - *pbr = i; - *br = j; - return; +static void ns_delay_scale(char *psc, char *sc, int delay_ns, + unsigned long clkrate) +{ + int pscale_tbl[4] = {1, 3, 5, 7}; + int scale_needed, scale, minscale = INT_MAX; + int i, j; + u32 remainder; + + scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC, + &remainder); + if (remainder) + scale_needed++; + + for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++) + for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) { + scale = pscale_tbl[i] * (2 << j); + if (scale >= scale_needed) { + if (scale < minscale) { + minscale = scale; + *psc = i; + *sc = j; + } + break; } } - pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld\ - ,we use the max prescaler value.\n", speed_hz, clkrate); - *pbr = ARRAY_SIZE(pbr_tbl) - 1; - *br = ARRAY_SIZE(brs) - 1; + if (minscale == INT_MAX) { + pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value", + delay_ns, clkrate); + *psc = ARRAY_SIZE(pscale_tbl) - 1; + *sc = SPI_CTAR_SCALE_BITS; + } } static int dspi_transfer_write(struct fsl_dspi *dspi) @@ -345,7 +391,10 @@ static int dspi_setup(struct spi_device *spi) { struct chip_data *chip; struct fsl_dspi *dspi = spi_master_get_devdata(spi->master); - unsigned char br = 0, pbr = 0, fmsz = 0; + u32 cs_sck_delay = 0, sck_cs_delay = 0; + unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0; + unsigned char pasc = 0, asc = 0, fmsz = 0; + unsigned long clkrate; if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) { fmsz = spi->bits_per_word - 1; @@ -362,18 +411,34 @@ static int dspi_setup(struct spi_device *spi) return -ENOMEM; } + of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay", + &cs_sck_delay); + + of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay", + &sck_cs_delay); + chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS | SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF; chip->void_write_data = 0; - hz_to_spi_baud(&pbr, &br, - spi->max_speed_hz, clk_get_rate(dspi->clk)); + clkrate = clk_get_rate(dspi->clk); + hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate); + + /* Set PCS to SCK delay scale values */ + ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate); + + /* Set After SCK delay scale values */ + ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate); chip->ctar_val = SPI_CTAR_FMSZ(fmsz) | SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0) | SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0) | SPI_CTAR_LSBFE(spi->mode & SPI_LSB_FIRST ? 1 : 0) + | SPI_CTAR_PCSSCK(pcssck) + | SPI_CTAR_CSSCK(cssck) + | SPI_CTAR_PASC(pasc) + | SPI_CTAR_ASC(asc) | SPI_CTAR_PBR(pbr) | SPI_CTAR_BR(br); |