| Message ID | 1406827995-30913-3-git-send-email-grygorii.strashko@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jul 31, 2014 at 08:33:15PM +0300, Grygorii Strashko wrote: > + if (np && master->cs_gpios != NULL && spi->cs_gpio >= 0) { > + /* SPI core parse and update master->cs_gpio */ > gpio_chipsel = true; > + gpio = spi->cs_gpio; > + } else if (pdata->chip_sel && > + chip_sel < pdata->num_chipselect && > + pdata->chip_sel[chip_sel] != SPI_INTERN_CS) { > + /* platform data defines chip_sel */ > + gpio_chipsel = true; > + gpio = pdata->chip_sel[chip_sel]; > + } This would all be a lot simpler and more direct if you were to arrange to use cs_gpio in the struct spi_device, and move you closer to converting to use more of the core functionality. > + if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) { > + retval = > + gpio_request(spi->cs_gpio, dev_name(&spi->dev)); > + if (retval) { > + dev_err(&spi->dev, > + "GPIO %d request failed\n", > + spi->cs_gpio); > + return -ENODEV; > + } > + gpio_direction_output(spi->cs_gpio, > + !(spi->mode & SPI_CS_HIGH)); > + internal_cs = false; It's much better to use gpio_request_one() rather than using gpio_request(), it's one function apart from anything else. The above is also discarding the return code of gpio_request() meaning it's broken for deferred probe. The error code should also appear in the error message.
Hi Mark, On 07/31/2014 10:35 PM, Mark Brown wrote: > On Thu, Jul 31, 2014 at 08:33:15PM +0300, Grygorii Strashko wrote: > >> + if (np && master->cs_gpios != NULL && spi->cs_gpio >= 0) { >> + /* SPI core parse and update master->cs_gpio */ >> gpio_chipsel = true; >> + gpio = spi->cs_gpio; >> + } else if (pdata->chip_sel && >> + chip_sel < pdata->num_chipselect && >> + pdata->chip_sel[chip_sel] != SPI_INTERN_CS) { >> + /* platform data defines chip_sel */ >> + gpio_chipsel = true; >> + gpio = pdata->chip_sel[chip_sel]; >> + } > > This would all be a lot simpler and more direct if you were to arrange > to use cs_gpio in the struct spi_device, and move you closer to > converting to use more of the core functionality. Unfortunately, I'm not sure this is good idea, because this part of code is used by Davinci arch which is non-DT platform. As result, this code was kept mostly unchanged. I can try to rework it, but I'd like to do it as standalone patch. Is it ok for you? > >> + if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) { >> + retval = >> + gpio_request(spi->cs_gpio, dev_name(&spi->dev)); >> + if (retval) { >> + dev_err(&spi->dev, >> + "GPIO %d request failed\n", >> + spi->cs_gpio); >> + return -ENODEV; >> + } >> + gpio_direction_output(spi->cs_gpio, >> + !(spi->mode & SPI_CS_HIGH)); >> + internal_cs = false; > > It's much better to use gpio_request_one() rather than using > gpio_request(), it's one function apart from anything else. The above > is also discarding the return code of gpio_request() meaning it's broken > for deferred probe. The error code should also appear in the error > message. > Thanks, will update. Regards, -grygorii -- 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
Hi Mark, On 08/01/2014 06:28 PM, Grygorii Strashko wrote: > Hi Mark, > On 07/31/2014 10:35 PM, Mark Brown wrote: >> On Thu, Jul 31, 2014 at 08:33:15PM +0300, Grygorii Strashko wrote: >> >>> + if (np && master->cs_gpios != NULL && spi->cs_gpio >= 0) { >>> + /* SPI core parse and update master->cs_gpio */ >>> gpio_chipsel = true; >>> + gpio = spi->cs_gpio; >>> + } else if (pdata->chip_sel && >>> + chip_sel < pdata->num_chipselect && >>> + pdata->chip_sel[chip_sel] != SPI_INTERN_CS) { >>> + /* platform data defines chip_sel */ >>> + gpio_chipsel = true; >>> + gpio = pdata->chip_sel[chip_sel]; >>> + } >> >> This would all be a lot simpler and more direct if you were to arrange >> to use cs_gpio in the struct spi_device, and move you closer to >> converting to use more of the core functionality. > > Unfortunately, I'm not sure this is good idea, because this part of > code is used by Davinci arch which is non-DT platform. > As result, this code was kept mostly unchanged. > > I can try to rework it, but I'd like to do it as standalone patch. > Is it ok for you? I've just sent updated version with additional patch where I reworked driver for using cs_gpio for both DT and non-DT cases. http://www.spinics.net/lists/arm-kernel/msg352382.html Regards, -grygorii -- 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/spi-davinci.txt b/Documentation/devicetree/bindings/spi/spi-davinci.txt index 6d0ac8d..f80887b 100644 --- a/Documentation/devicetree/bindings/spi/spi-davinci.txt +++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt @@ -8,7 +8,8 @@ Required properties: - "ti,dm6441-spi" for SPI used similar to that on DM644x SoC family - "ti,da830-spi" for SPI used similar to that on DA8xx SoC family - reg: Offset and length of SPI controller register space -- num-cs: Number of chip selects +- num-cs: Number of chip selects. This includes internal as well as + GPIO chip selects. - ti,davinci-spi-intr-line: interrupt line used to connect the SPI IP to the interrupt controller within the SoC. Possible values are 0 and 1. Manual says one of the two possible interrupt @@ -17,6 +18,12 @@ Required properties: - interrupts: interrupt number mapped to CPU. - clocks: spi clk phandle +Optional: +- cs-gpios: gpio chip selects + For example to have 3 internal CS and 2 GPIO CS, user could define + cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>; + where first three are internal CS and last two are GPIO CS. + Example of a NOR flash slave device (n25q032) connected to DaVinci SPI controller device over the SPI bus. diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index 2477af4..6aa04d1 100644 --- a/drivers/spi/spi-davinci.c +++ b/drivers/spi/spi-davinci.c @@ -30,6 +30,7 @@ #include <linux/edma.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/of_gpio.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> #include <linux/slab.h> @@ -207,17 +208,28 @@ static inline void clear_io_bits(void __iomem *addr, u32 bits) static void davinci_spi_chipselect(struct spi_device *spi, int value) { struct davinci_spi *dspi; + struct device_node *np = spi->dev.of_node; struct davinci_spi_platform_data *pdata; + struct spi_master *master = spi->master; u8 chip_sel = spi->chip_select; u16 spidat1 = CS_DEFAULT; bool gpio_chipsel = false; + int gpio; dspi = spi_master_get_devdata(spi->master); pdata = &dspi->pdata; - if (pdata->chip_sel && chip_sel < pdata->num_chipselect && - pdata->chip_sel[chip_sel] != SPI_INTERN_CS) + if (np && master->cs_gpios != NULL && spi->cs_gpio >= 0) { + /* SPI core parse and update master->cs_gpio */ gpio_chipsel = true; + gpio = spi->cs_gpio; + } else if (pdata->chip_sel && + chip_sel < pdata->num_chipselect && + pdata->chip_sel[chip_sel] != SPI_INTERN_CS) { + /* platform data defines chip_sel */ + gpio_chipsel = true; + gpio = pdata->chip_sel[chip_sel]; + } /* * Board specific chip select logic decides the polarity and cs @@ -225,9 +237,9 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) */ if (gpio_chipsel) { if (value == BITBANG_CS_ACTIVE) - gpio_set_value(pdata->chip_sel[chip_sel], 0); + gpio_set_value(gpio, 0); else - gpio_set_value(pdata->chip_sel[chip_sel], 1); + gpio_set_value(gpio, 1); } else { if (value == BITBANG_CS_ACTIVE) { spidat1 |= SPIDAT1_CSHOLD_MASK; @@ -390,17 +402,36 @@ static int davinci_spi_setup(struct spi_device *spi) int retval = 0; struct davinci_spi *dspi; struct davinci_spi_platform_data *pdata; + struct spi_master *master = spi->master; + struct device_node *np = spi->dev.of_node; + bool internal_cs = true; dspi = spi_master_get_devdata(spi->master); pdata = &dspi->pdata; if (!(spi->mode & SPI_NO_CS)) { - if ((pdata->chip_sel == NULL) || - (pdata->chip_sel[spi->chip_select] == SPI_INTERN_CS)) - set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select); - + if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) { + retval = + gpio_request(spi->cs_gpio, dev_name(&spi->dev)); + if (retval) { + dev_err(&spi->dev, + "GPIO %d request failed\n", + spi->cs_gpio); + return -ENODEV; + } + gpio_direction_output(spi->cs_gpio, + !(spi->mode & SPI_CS_HIGH)); + internal_cs = false; + } else if (pdata->chip_sel && + spi->chip_select < pdata->num_chipselect && + pdata->chip_sel[spi->chip_select] != SPI_INTERN_CS) { + internal_cs = false; + } } + if (internal_cs) + set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select); + if (spi->mode & SPI_READY) set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK); @@ -412,6 +443,15 @@ static int davinci_spi_setup(struct spi_device *spi) return retval; } +static void davinci_spi_cleanup(struct spi_device *spi) +{ + struct spi_master *master = spi->master; + struct device_node *np = spi->dev.of_node; + + if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) + gpio_free(spi->cs_gpio); +} + static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status) { struct device *sdev = dspi->bitbang.master->dev.parent; @@ -810,6 +850,8 @@ static int spi_davinci_get_pdata(struct platform_device *pdev, /* * default num_cs is 1 and all chipsel are internal to the chip + * indicated by chip_sel being NULL or cs_gpios being NULL or + * set to -ENOENT. num-cs includes internal as well as gpios. * indicated by chip_sel being NULL. GPIO based CS is not * supported yet in DT bindings. */ @@ -921,6 +963,7 @@ static int davinci_spi_probe(struct platform_device *pdev) master->num_chipselect = pdata->num_chipselect; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16); master->setup = davinci_spi_setup; + master->cleanup = davinci_spi_cleanup; dspi->bitbang.chipselect = davinci_spi_chipselect; dspi->bitbang.setup_transfer = davinci_spi_setup_transfer;