@@ -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.
@@ -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 +402,41 @@ 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)) {
+ unsigned long flags;
+
+ flags = GPIOF_DIR_OUT;
+ if (spi->mode & SPI_CS_HIGH)
+ flags |= GPIOF_INIT_LOW;
+ else
+ flags |= GPIOF_INIT_HIGH;
+ retval = gpio_request_one(spi->cs_gpio,
+ flags, dev_name(&spi->dev));
+ if (retval) {
+ dev_err(&spi->dev,
+ "GPIO %d request failed (%d)\n",
+ spi->cs_gpio, retval);
+ return retval;
+ }
+ 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 +448,15 @@ 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 +855,8 @@ 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 +968,7 @@ 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;