On Mon, 12 Nov 2012 16:28:22 -0500, Murali Karicheri <m-karicheri2@xxxxxx> wrote:
This adds OF support to DaVinci SPI controller to configure platform
data through device bindings.
Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
Hi Murali,
Comments below...
---
.../devicetree/bindings/spi/spi-davinci.txt | 50 ++++++++++++
drivers/spi/spi-davinci.c | 80 +++++++++++++++++++-
2 files changed, 126 insertions(+), 4 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..0369369
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt
@@ -0,0 +1,50 @@
+Davinci SPI controller device bindings
+
+Required properties:
+- #address-cells: number of cells required to define a chip select
+ address on the SPI bus.
Will this *ever* be something other than '1'?
+- #size-cells: should be zero.
+- compatible:
+ - "ti,davinci-spi"
Please use the actual model of the chip here. Don't try to be generic
with the compatible string. A driver can bind against more than one
compatible value and new devices can claim compatiblity with old by
including the old compatible string in this list.
+- reg: Offset and length of SPI controller register space
+- ti,davinci-spi-version: SPI version :- "1.0" or "2.0"
Usually this is determined from the compatible value directly (which is
why compatible strings shouldn't be generic). Don't use a separate
property for it.
+- ti,davinci-spi-num-cs: Number of chip selects
+- ti,davinci-spi-intr-line: interrupt line used to connect the SPI
+ IP to the ARM interrupt controller withn the SoC. Possible values
+ are 0 and 1.
? Isn't that what the interrupts property is for? I don't understand why
this is needed from the description.
+- 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.
+
+spi:spi0@20BF0000 {
spi@20BF0000 (use 'spi' not 'spi0')
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "ti,davinci-spi";
+ reg = <0x20BF0000 0x1000>;
+ ti,davinci-spi-version = "1.0";
+ ti,davinci-spi-num-cs = <4>;
+ ti,davinci-spi-intr-line = <0>;
+ interrupts = <338>;
+ clocks = <&clkspi>;
+
+ flash: n25q032@0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "st,m25p32";
+ spi-max-frequency = <25000000>;
+ reg = <0>;
+
+ partition@0 {
+ label = "u-boot-spl";
+ reg = <0x0 0x80000>;
+ read-only;
+ };
+
+ partition@1 {
+ label = "test";
+ reg = <0x80000 0x380000>;
+ };
+ };
+};
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index 71a6423..0f50319 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -26,6 +26,9 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/slab.h>
@@ -788,6 +791,69 @@ rx_dma_failed:
return r;
}
+#if defined(CONFIG_OF)
+static const struct of_device_id davinci_spi_of_match[] = {
+ {
+ .compatible = "ti,davinci-spi",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, davini_spi_of_match);
+
+/**
+ * spi_davinci_get_pdata - Get platform_data from DTS binding
+ * @pdev: ptr to platform data
+ *
+ * Parses and populate platform_data from device tree bindings.
+ *
+ * NOTE: Not all platform_data params are supported currently.
+ */
+static struct davinci_spi_platform_data
+ *spi_davinci_get_pdata(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct davinci_spi_platform_data *pdata;
+ unsigned int num_cs, intr_line = 0;
+ const char *version;
+
+ if (pdev->dev.platform_data)
+ return pdev->dev.platform_data;
+
+ if (!pdev->dev.of_node)
+ return NULL;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ pdev->dev.platform_data = pdata;
+ if (!pdata)
+ return NULL;
Since pdata must always be present, roll it directly into struct
spi_davinci and get rid of the kzmalloc here. It is less expensive and
is simpler code.
+
+ /* default version is 1.0 */
+ pdata->version = SPI_VERSION_1;
+ of_property_read_string(node, "ti,davinci-spi-version", &version);
+ if (!strcmp(version, "2.0"))
+ 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, "ti,davinci-spi-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 pdev->dev.platform_data;
+}
+#else
+#define davinci_spi_of_match NULL
+static struct davinci_spi_platform_data
+ *spi_davinci_get_pdata(struct platform_device *pdev)
+{
+ return pdev->dev.platform_data;
+}
+#endif
+
/**
* davinci_spi_probe - probe function for SPI Master Controller
* @pdev: platform_device structure which contains plateform specific data
@@ -801,16 +867,16 @@ rx_dma_failed:
*/
static int __devinit davinci_spi_probe(struct platform_device *pdev)
{
+ resource_size_t dma_rx_chan = SPI_NO_RESOURCE;
+ resource_size_t dma_tx_chan = SPI_NO_RESOURCE;
+ struct davinci_spi_platform_data *pdata;
struct spi_master *master;
struct davinci_spi *dspi;
- struct davinci_spi_platform_data *pdata;
struct resource *r, *mem;
- resource_size_t dma_rx_chan = SPI_NO_RESOURCE;
- resource_size_t dma_tx_chan = SPI_NO_RESOURCE;
int i = 0, ret = 0;
u32 spipc0;
- pdata = pdev->dev.platform_data;
+ pdata = spi_davinci_get_pdata(pdev);
if (pdata == NULL) {
ret = -ENODEV;
goto err;
@@ -851,7 +917,11 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
goto release_region;
}
+ /* first get irq through resource table, else try of irq method */
dspi->irq = platform_get_irq(pdev, 0);
+ if (dspi->irq <= 0)
+ dspi->irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+
This should never be needed. The irq should already be populated in the
platform_device.
if (dspi->irq <= 0) {
ret = -EINVAL;
goto unmap_io;
@@ -875,6 +945,7 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
}
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;
@@ -1010,6 +1081,7 @@ 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
