[PATCH - v2] spi: davinci: add OF support for the spi controller
Murali Karicheri
m-karicheri2 at ti.com
Wed Dec 12 08:20:39 EST 2012
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>
---
- 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
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