| Message ID | 20170423111837.19460-1-Leif.Middelschulte@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 23 April 2017 at 13:18, Leif Middelschulte <leif.middelschulte@gmail.com> wrote: > From: Leif Middelschulte <leif.middelschulte@gmail.com> > > This patch implements consideration of the SPI_READY mode flag as > defined in spi.h. It extends the device tree bindings to support > the values defined by the reference manual for the DRCTL field. > > Thus supporting edge-triggered and level-triggered bursts. > > Signed-off-by: Leif Middelschulte <Leif.Middelschulte@gmail.com> > --- > .../devicetree/bindings/spi/fsl-imx-cspi.txt | 5 +++++ > drivers/spi/spi-imx.c | 23 ++++++++++++++++++++-- > 2 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt > index 8bc95e2fc47f..890b3ff3325f 100644 > --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt > +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt You are modifying device tree documentation, you need to CC the appropriate mailing list as well (as I now did). > @@ -23,6 +23,10 @@ See the clock consumer binding, > Obsolete properties: > - fsl,spi-num-chipselects : Contains the number of the chipselect > > +Optional properties: > +- fsl,spi-drctl: Integer, representing the value of DRCTL. Note that to > +enable the DRCTL consideration, the SPI_READY mode-flag needs to be set. Maybe document the valid values here as well? Also spi-drctl isn't really a nice name, maybe something human understandable that doesn't require looking into the datasheet? > + > Example: > > ecspi@70010000 { > @@ -35,4 +39,5 @@ ecspi@70010000 { > <&gpio3 25 0>; /* GPIO3_25 */ > dmas = <&sdma 3 7 1>, <&sdma 4 7 2>; > dma-names = "rx", "tx"; > + fsl,spi-drctl = <1>; > }; > diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c > index 9a7c62f471dc..647a4bf18705 100644 > --- a/drivers/spi/spi-imx.c > +++ b/drivers/spi/spi-imx.c > @@ -95,6 +95,7 @@ struct spi_imx_data { > unsigned int spi_bus_clk; > > unsigned int bytes_per_word; > + unsigned int spi_drctl; > > unsigned int count; > void (*tx)(struct spi_imx_data *); > @@ -246,6 +247,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, > #define MX51_ECSPI_CTRL_XCH (1 << 2) > #define MX51_ECSPI_CTRL_SMC (1 << 3) > #define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4) > +#define MX51_ECSPI_CTRL_DRCTL(drctl) ((drctl) << 16) > #define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8 > #define MX51_ECSPI_CTRL_PREDIV_OFFSET 12 > #define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18) > @@ -355,6 +357,12 @@ static int mx51_ecspi_config(struct spi_device *spi, > */ > ctrl |= MX51_ECSPI_CTRL_MODE_MASK; > > + /* > + * Enable SPI_RDY handling (falling edge/level triggered). > + */ > + if (spi->mode & SPI_READY) > + ctrl |= MX51_ECSPI_CTRL_DRCTL(spi_imx->spi_drctl); > + > /* set clock speed */ > ctrl |= mx51_ecspi_clkdiv(spi_imx, config->speed_hz, &clk); > spi_imx->spi_bus_clk = clk; > @@ -1173,7 +1181,7 @@ static int spi_imx_probe(struct platform_device *pdev) > struct spi_master *master; > struct spi_imx_data *spi_imx; > struct resource *res; > - int i, ret, irq; > + int i, ret, irq, spi_drctl; > > if (!np && !mxc_platform_info) { > dev_err(&pdev->dev, "can't get the platform data\n"); > @@ -1181,6 +1189,15 @@ static int spi_imx_probe(struct platform_device *pdev) > } > > master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data)); > + ret = of_property_read_u32(np, "fsl,spi-drctl", &spi_drctl); > + if ((ret < 0) || (spi_drctl == 0x3)) { > + // '11' is reserved Don't use C99 comments, use /* */ comments. > + spi_drctl = 0; Here you say '11' is reserved and force 0 if set > + } else { > + // only the values '00', '01' and '11' are valid And here you say '11' is valid. So which is it? Did you mean '10'? > + spi_drctl &= 0x3; Also with this code flow if fsl,spi-drctl is set to <7>, it will cause spi_drctl set to '11' / 0x3. Maybe it would be easier to do if (ret < 0 || spi_drctl >= 0x3) spi_drctl = 0; to only accept valid values. Assuming '11' is the invalid one and not '10'. Regards Jonas -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt index 8bc95e2fc47f..890b3ff3325f 100644 --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt @@ -23,6 +23,10 @@ See the clock consumer binding, Obsolete properties: - fsl,spi-num-chipselects : Contains the number of the chipselect +Optional properties: +- fsl,spi-drctl: Integer, representing the value of DRCTL. Note that to +enable the DRCTL consideration, the SPI_READY mode-flag needs to be set. + Example: ecspi@70010000 { @@ -35,4 +39,5 @@ ecspi@70010000 { <&gpio3 25 0>; /* GPIO3_25 */ dmas = <&sdma 3 7 1>, <&sdma 4 7 2>; dma-names = "rx", "tx"; + fsl,spi-drctl = <1>; }; diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 9a7c62f471dc..647a4bf18705 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -95,6 +95,7 @@ struct spi_imx_data { unsigned int spi_bus_clk; unsigned int bytes_per_word; + unsigned int spi_drctl; unsigned int count; void (*tx)(struct spi_imx_data *); @@ -246,6 +247,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, #define MX51_ECSPI_CTRL_XCH (1 << 2) #define MX51_ECSPI_CTRL_SMC (1 << 3) #define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4) +#define MX51_ECSPI_CTRL_DRCTL(drctl) ((drctl) << 16) #define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8 #define MX51_ECSPI_CTRL_PREDIV_OFFSET 12 #define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18) @@ -355,6 +357,12 @@ static int mx51_ecspi_config(struct spi_device *spi, */ ctrl |= MX51_ECSPI_CTRL_MODE_MASK; + /* + * Enable SPI_RDY handling (falling edge/level triggered). + */ + if (spi->mode & SPI_READY) + ctrl |= MX51_ECSPI_CTRL_DRCTL(spi_imx->spi_drctl); + /* set clock speed */ ctrl |= mx51_ecspi_clkdiv(spi_imx, config->speed_hz, &clk); spi_imx->spi_bus_clk = clk; @@ -1173,7 +1181,7 @@ static int spi_imx_probe(struct platform_device *pdev) struct spi_master *master; struct spi_imx_data *spi_imx; struct resource *res; - int i, ret, irq; + int i, ret, irq, spi_drctl; if (!np && !mxc_platform_info) { dev_err(&pdev->dev, "can't get the platform data\n"); @@ -1181,6 +1189,15 @@ static int spi_imx_probe(struct platform_device *pdev) } master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data)); + ret = of_property_read_u32(np, "fsl,spi-drctl", &spi_drctl); + if ((ret < 0) || (spi_drctl == 0x3)) { + // '11' is reserved + spi_drctl = 0; + } else { + // only the values '00', '01' and '11' are valid + spi_drctl &= 0x3; + } + if (!master) return -ENOMEM; @@ -1216,7 +1233,9 @@ static int spi_imx_probe(struct platform_device *pdev) spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message; spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx)) - spi_imx->bitbang.master->mode_bits |= SPI_LOOP; + spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY; + + spi_imx->spi_drctl = spi_drctl; init_completion(&spi_imx->xfer_done);