[PATCH - v2] spi: davinci: add OF support for the spi controller
Grant Likely
grant.likely at secretlab.ca
Sat Dec 15 11:27:58 EST 2012
On Tue, 11 Dec 2012 16:20:39 -0500, Murali Karicheri <m-karicheri2 at ti.com> wrote:
> This adds OF support to DaVinci SPI controller to configure platform
> data through device bindings. Also replaces clk_enable() with
> of clk_prepare_enable() as well as clk_disable() with
> clk_disable_unprepare().
>
> Signed-off-by: Murali Karicheri <m-karicheri2 at ti.com>
> Reviewed-by : Grant Likely <grant.likely at secretlab.ca>
Applied, thanks.
I did remove the OF_ALIAS_N property though. I know the COMPATIBLE one
uses it, but it is actually kind of redundant since it can also be
determined by counting the number of OF_ALIAS_* entries, and having the
_N one in there means extra work needs to be done to filter it out.
Also, I had to add a #ifndef _LINUX_OF_PRIVATE_H wrapper around the
whole header file. This is needed for all header files to protect
against multiple includes.
g.
> ---
> - Change log
> - v2 - changed the compatibility strings to include soc name
> - changed ti,davinci-num-cs to num-cs
> v1 - removed attribute for spi version. instead, compatibility string is
> modified to include version info.
> - pdata ptr in davinci_spi_platform_data is replaced with struct itself.
> - spi_davinci_get_pdata() now populates the pdata in the above structure
> with parsed values from DT bindings.
> - rebased to v3.7 rc7 of linux-next
> - replaces clk_* APIs with their prepare/unprepare version
> .../devicetree/bindings/spi/spi-davinci.txt | 51 ++++++++++
> drivers/spi/spi-davinci.c | 102 +++++++++++++++++---
> 2 files changed, 139 insertions(+), 14 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/spi/spi-davinci.txt
>
> diff --git a/Documentation/devicetree/bindings/spi/spi-davinci.txt b/Documentation/devicetree/bindings/spi/spi-davinci.txt
> new file mode 100644
> index 0000000..8cb3fee
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt
> @@ -0,0 +1,51 @@
> +Davinci SPI controller device bindings
> +
> +Required properties:
> +- #address-cells: number of cells required to define a chip select
> + address on the SPI bus. Should be set to 1.
> +- #size-cells: should be zero.
> +- compatible:
> + - "ti,dm644x-spi" for SPI used similar to that on DM644x SoC family
> + - "ti,da8xx-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
> +- ti,davinci-spi-intr-line: interrupt line used to connect the SPI
> + IP to the interrupt controller withn the SoC. Possible values
> + are 0 and 1. Manual says one of the two possible interrupt
> + lines can be tied to the interrupt controller. Set this
> + based on a specifc SoC configuration.
> +- interrupts: interrupt number offset at the irq parent
> +- clocks: spi clk phandle
> +
> +Example of a NOR flash slave device (n25q032) connected to DaVinci
> +SPI controller device over the SPI bus.
> +
> +spi0:spi at 20BF0000 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + compatible = "ti,dm644x-spi";
> + reg = <0x20BF0000 0x1000>;
> + num-cs = <4>;
> + ti,davinci-spi-intr-line = <0>;
> + interrupts = <338>;
> + clocks = <&clkspi>;
> +
> + flash: n25q032 at 0 {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + compatible = "st,m25p32";
> + spi-max-frequency = <25000000>;
> + reg = <0>;
> +
> + partition at 0 {
> + label = "u-boot-spl";
> + reg = <0x0 0x80000>;
> + read-only;
> + };
> +
> + partition at 1 {
> + label = "test";
> + reg = <0x80000 0x380000>;
> + };
> + };
> +};
> diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
> index 147dfa8..e5d8489 100644
> --- a/drivers/spi/spi-davinci.c
> +++ b/drivers/spi/spi-davinci.c
> @@ -28,6 +28,8 @@
> #include <linux/dmaengine.h>
> #include <linux/dma-mapping.h>
> #include <linux/edma.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> #include <linux/spi/spi.h>
> #include <linux/spi/spi_bitbang.h>
> #include <linux/slab.h>
> @@ -135,7 +137,7 @@ struct davinci_spi {
> int dma_rx_chnum;
> int dma_tx_chnum;
>
> - struct davinci_spi_platform_data *pdata;
> + struct davinci_spi_platform_data pdata;
>
> void (*get_rx)(u32 rx_data, struct davinci_spi *);
> u32 (*get_tx)(struct davinci_spi *);
> @@ -213,7 +215,7 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value)
> bool gpio_chipsel = false;
>
> dspi = spi_master_get_devdata(spi->master);
> - pdata = dspi->pdata;
> + pdata = &dspi->pdata;
>
> if (pdata->chip_sel && chip_sel < pdata->num_chipselect &&
> pdata->chip_sel[chip_sel] != SPI_INTERN_CS)
> @@ -392,7 +394,7 @@ static int davinci_spi_setup(struct spi_device *spi)
> struct davinci_spi_platform_data *pdata;
>
> dspi = spi_master_get_devdata(spi->master);
> - pdata = dspi->pdata;
> + pdata = &dspi->pdata;
>
> /* if bits per word length is zero then set it default 8 */
> if (!spi->bits_per_word)
> @@ -534,7 +536,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
> struct scatterlist sg_rx, sg_tx;
>
> dspi = spi_master_get_devdata(spi->master);
> - pdata = dspi->pdata;
> + pdata = &dspi->pdata;
> spicfg = (struct davinci_spi_config *)spi->controller_data;
> if (!spicfg)
> spicfg = &davinci_spi_default_cfg;
> @@ -758,6 +760,70 @@ rx_dma_failed:
> return r;
> }
>
> +#if defined(CONFIG_OF)
> +static const struct of_device_id davinci_spi_of_match[] = {
> + {
> + .compatible = "ti,dm644x-spi",
> + },
> + {
> + .compatible = "ti,da8xx-spi",
> + .data = (void *)SPI_VERSION_2,
> + },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, davini_spi_of_match);
> +
> +/**
> + * spi_davinci_get_pdata - Get platform data from DTS binding
> + * @pdev: ptr to platform data
> + * @dspi: ptr to driver data
> + *
> + * Parses and populates pdata in dspi from device tree bindings.
> + *
> + * NOTE: Not all platform data params are supported currently.
> + */
> +static int spi_davinci_get_pdata(struct platform_device *pdev,
> + struct davinci_spi *dspi)
> +{
> + struct device_node *node = pdev->dev.of_node;
> + struct davinci_spi_platform_data *pdata;
> + unsigned int num_cs, intr_line = 0;
> + const struct of_device_id *match;
> +
> + pdata = &dspi->pdata;
> +
> + pdata->version = SPI_VERSION_1;
> + match = of_match_device(of_match_ptr(davinci_spi_of_match),
> + &pdev->dev);
> + if (!match)
> + return -ENODEV;
> +
> + /* match data has the SPI version number for SPI_VERSION_2 */
> + if (match->data == (void *)SPI_VERSION_2)
> + pdata->version = SPI_VERSION_2;
> +
> + /*
> + * default num_cs is 1 and all chipsel are internal to the chip
> + * indicated by chip_sel being NULL. GPIO based CS is not
> + * supported yet in DT bindings.
> + */
> + num_cs = 1;
> + of_property_read_u32(node, "num-cs", &num_cs);
> + pdata->num_chipselect = num_cs;
> + of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line);
> + pdata->intr_line = intr_line;
> + return 0;
> +}
> +#else
> +#define davinci_spi_of_match NULL
> +static struct davinci_spi_platform_data
> + *spi_davinci_get_pdata(struct platform_device *pdev,
> + struct davinci_spi *dspi)
> +{
> + return -ENODEV;
> +}
> +#endif
> +
> /**
> * davinci_spi_probe - probe function for SPI Master Controller
> * @pdev: platform_device structure which contains plateform specific data
> @@ -780,12 +846,6 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
> int i = 0, ret = 0;
> u32 spipc0;
>
> - pdata = pdev->dev.platform_data;
> - if (pdata == NULL) {
> - ret = -ENODEV;
> - goto err;
> - }
> -
> master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
> if (master == NULL) {
> ret = -ENOMEM;
> @@ -800,6 +860,19 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
> goto free_master;
> }
>
> + if (pdev->dev.platform_data) {
> + pdata = pdev->dev.platform_data;
> + dspi->pdata = *pdata;
> + } else {
> + /* update dspi pdata with that from the DT */
> + ret = spi_davinci_get_pdata(pdev, dspi);
> + if (ret < 0)
> + goto free_master;
> + }
> +
> + /* pdata in dspi is now updated and point pdata to that */
> + pdata = &dspi->pdata;
> +
> r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (r == NULL) {
> ret = -ENOENT;
> @@ -807,7 +880,6 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
> }
>
> dspi->pbase = r->start;
> - dspi->pdata = pdata;
>
> mem = request_mem_region(r->start, resource_size(r), pdev->name);
> if (mem == NULL) {
> @@ -843,8 +915,9 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
> ret = -ENODEV;
> goto put_master;
> }
> - clk_enable(dspi->clk);
> + clk_prepare_enable(dspi->clk);
>
> + master->dev.of_node = pdev->dev.of_node;
> master->bus_num = pdev->id;
> master->num_chipselect = pdata->num_chipselect;
> master->setup = davinci_spi_setup;
> @@ -927,7 +1000,7 @@ free_dma:
> dma_release_channel(dspi->dma_rx);
> dma_release_channel(dspi->dma_tx);
> free_clk:
> - clk_disable(dspi->clk);
> + clk_disable_unprepare(dspi->clk);
> clk_put(dspi->clk);
> put_master:
> spi_master_put(master);
> @@ -963,7 +1036,7 @@ static int __devexit davinci_spi_remove(struct platform_device *pdev)
>
> spi_bitbang_stop(&dspi->bitbang);
>
> - clk_disable(dspi->clk);
> + clk_disable_unprepare(dspi->clk);
> clk_put(dspi->clk);
> spi_master_put(master);
> free_irq(dspi->irq, dspi);
> @@ -978,6 +1051,7 @@ static struct platform_driver davinci_spi_driver = {
> .driver = {
> .name = "spi_davinci",
> .owner = THIS_MODULE,
> + .of_match_table = davinci_spi_of_match,
> },
> .probe = davinci_spi_probe,
> .remove = __devexit_p(davinci_spi_remove),
> --
> 1.7.9.5
>
--
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.
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