[PATCH 2/2] spi: davinci: support adding delay between transmission

@@ -24,6 +24,22 @@ Optional:
 	cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>;
 	where first three are internal CS and last two are GPIO CS.
 
+Optional properties for slave devices:
+SPI slave nodes can contain the following properties.
+Not all SPI Peripherals from Texas Instruments support this.
+Please check SPI peripheral documentation for a device before using these.
+
+- ti,davinci-spi-wdelay : delay between transmissions.
+- ti,davinci-spi-odd-parity : odd partity enabled
+   OR
+  ti,davinci-spi-even-parity : even parity enabled
+- ti,davinci-spi-io-type: io type (check platform_data/spi-davinci.h)
+- ti,davinci-spi-disable-timer: disable CS timer (SPIFMTn)
+- ti,davinci-spi-c2t-delay: c2t delay
+- ti,davinci-spi-t2c-delay: t2c delay
+- ti,davinci-spi-t2e-delay: t2e delay
+- ti,davinci-spi-c2e-delay: c2e delay
+
 Example of a NOR flash slave device (n25q032) connected to DaVinci
 SPI controller device over the SPI bus.
 

@@ -43,6 +59,8 @@ spi0:spi at 20BF0000 {
 		compatible = "st,m25p32";
 		spi-max-frequency = <25000000>;
 		reg = <0>;
+		ti,davinci-spi-c2t-delay = <8>;
+		ti,davinci-spi-t2c-delay = <8>;
 
 		partition at 0 {
 			label = "u-boot-spl";

@@ -65,6 +65,7 @@
 
 /* SPIDAT1 (upper 16 bit defines) */
 #define SPIDAT1_CSHOLD_MASK	BIT(12)
+#define SPIDAT1_WDEL		BIT(10)
 
 /* SPIGCR1 */
 #define SPIGCR1_CLKMOD_MASK	BIT(1)

@@ -209,6 +210,7 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value)
 {
 	struct davinci_spi *dspi;
 	struct davinci_spi_platform_data *pdata;
+	struct davinci_spi_config *spicfg = spi->controller_data;
 	u8 chip_sel = spi->chip_select;
 	u16 spidat1 = CS_DEFAULT;
 	bool gpio_chipsel = false;

@@ -223,6 +225,10 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value)
 		gpio = spi->cs_gpio;
 	}
 
+	/* program delay transfers if tx_delay is non zero */
+	if (spicfg->wdelay)
+		spidat1 |= SPIDAT1_WDEL;
+
 	/*
 	 * Board specific chip select logic decides the polarity and cs
 	 * line for the controller

@@ -237,9 +243,9 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value)
 			spidat1 |= SPIDAT1_CSHOLD_MASK;
 			spidat1 &= ~(0x1 << chip_sel);
 		}
-
-		iowrite16(spidat1, dspi->base + SPIDAT1 + 2);
 	}
+
+	iowrite16(spidat1, dspi->base + SPIDAT1 + 2);
 }
 
 /**

@@ -285,7 +291,7 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
 	int prescale;
 
 	dspi = spi_master_get_devdata(spi->master);
-	spicfg = (struct davinci_spi_config *)spi->controller_data;
+	spicfg = spi->controller_data;
 	if (!spicfg)
 		spicfg = &davinci_spi_default_cfg;
 

@@ -333,6 +339,14 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
 		spifmt |= SPIFMT_PHASE_MASK;
 
 	/*
+	* Assume wdelay is used only on SPI peripherals that has this field
+	* in SPIFMTn register and when it's configured from board file or DT.
+	*/
+	if (spicfg->wdelay)
+		spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
+				& SPIFMT_WDELAY_MASK);
+
+	/*
 	 * Version 1 hardware supports two basic SPI modes:
 	 *  - Standard SPI mode uses 4 pins, with chipselect
 	 *  - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)

@@ -349,9 +363,6 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
 
 		u32 delay = 0;
 
-		spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
-							& SPIFMT_WDELAY_MASK);
-
 		if (spicfg->odd_parity)
 			spifmt |= SPIFMT_ODD_PARITY_MASK;
 

@@ -383,6 +394,55 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
 	return 0;
 }
 
+static int davinci_spi_of_setup(struct spi_device *spi)
+{
+	struct davinci_spi_config *spicfg = spi->controller_data;
+	struct device_node *np = spi->dev.of_node;
+	u32 prop;
+	int len;
+
+	if (spicfg == NULL && np) {
+		spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL);
+		if (!spicfg)
+			return -ENOMEM;
+		*spicfg = davinci_spi_default_cfg;
+		/* override with dt configured values */
+		if (!of_property_read_u32(np,
+					  "ti,davinci-spi-wdelay", &prop))
+			spicfg->wdelay = (u8)prop;
+		if (of_find_property(np,
+				     "ti,davinci-spi-odd-parity", &len)) {
+			spicfg->parity_enable = 1;
+			spicfg->odd_parity = 1;
+		} else if (of_find_property(np, "ti,davinci-spi-even-parity",
+					    &len)) {
+			spicfg->parity_enable = 1;
+			spicfg->odd_parity = 0;
+		}
+		if (!of_property_read_u32(np, "ti,davinci-spi-io-type",
+					  &prop))
+			spicfg->io_type = (u8)prop;
+		if (of_find_property(np,
+				     "ti,davinci-spi-disable-timer", &len))
+			spicfg->timer_disable = 1;
+		if (!of_property_read_u32(np,
+					  "ti,davinci-spi-c2t-delay", &prop))
+			spicfg->c2tdelay = (u8)prop;
+		if (!of_property_read_u32(np,
+					  "ti,davinci-spi-t2c-delay", &prop))
+			spicfg->t2cdelay = (u8)prop;
+		if (!of_property_read_u32(np,
+					  "ti,davinci-spi-t2e-delay", &prop))
+			spicfg->t2edelay = (u8)prop;
+		if (!of_property_read_u32(np,
+					  "ti,davinci-spi-c2e-delay", &prop))
+			spicfg->c2edelay = (u8)prop;
+		spi->controller_data = spicfg;
+	}
+
+	return 0;
+}
+
 /**
  * davinci_spi_setup - This functions will set default transfer method
  * @spi: spi device on which data transfer to be done

@@ -436,11 +496,17 @@ static int davinci_spi_setup(struct spi_device *spi)
 	else
 		clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
 
-	return retval;
+	return davinci_spi_of_setup(spi);
 }
 
 static void davinci_spi_cleanup(struct spi_device *spi)
 {
+	struct davinci_spi_config *spicfg = spi->controller_data;
+
+	spi->controller_data = NULL;
+	if (spi->dev.of_node)
+		kfree(spicfg);
+
 	if (spi->cs_gpio >= 0)
 		gpio_free(spi->cs_gpio);
 }