From a700f2d8e79ff80041078f160fe1edccf89b0c66 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 23 Sep 2015 12:33:14 -0300
Subject: Linux-libre 4.2.1-gnu

---
 drivers/spi/spi-orion.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

(limited to 'drivers/spi/spi-orion.c')

diff --git a/drivers/spi/spi-orion.c b/drivers/spi/spi-orion.c
index 8cad107a5..a87cfd4ba 100644
--- a/drivers/spi/spi-orion.c
+++ b/drivers/spi/spi-orion.c
@@ -41,6 +41,11 @@
 #define ORION_SPI_DATA_OUT_REG		0x08
 #define ORION_SPI_DATA_IN_REG		0x0c
 #define ORION_SPI_INT_CAUSE_REG		0x10
+#define ORION_SPI_TIMING_PARAMS_REG	0x18
+
+#define ORION_SPI_TMISO_SAMPLE_MASK	(0x3 << 6)
+#define ORION_SPI_TMISO_SAMPLE_1	(1 << 6)
+#define ORION_SPI_TMISO_SAMPLE_2	(2 << 6)
 
 #define ORION_SPI_MODE_CPOL		(1 << 11)
 #define ORION_SPI_MODE_CPHA		(1 << 12)
@@ -70,6 +75,7 @@ struct orion_spi_dev {
 	unsigned int		min_divisor;
 	unsigned int		max_divisor;
 	u32			prescale_mask;
+	bool			is_errata_50mhz_ac;
 };
 
 struct orion_spi {
@@ -195,6 +201,41 @@ orion_spi_mode_set(struct spi_device *spi)
 	writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
 }
 
+static void
+orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
+{
+	u32 reg;
+	struct orion_spi *orion_spi;
+
+	orion_spi = spi_master_get_devdata(spi->master);
+
+	/*
+	 * Erratum description: (Erratum NO. FE-9144572) The device
+	 * SPI interface supports frequencies of up to 50 MHz.
+	 * However, due to this erratum, when the device core clock is
+	 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
+	 * clock and CPOL=CPHA=1 there might occur data corruption on
+	 * reads from the SPI device.
+	 * Erratum Workaround:
+	 * Work in one of the following configurations:
+	 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
+	 * Register".
+	 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
+	 * Register" before setting the interface.
+	 */
+	reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
+	reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
+
+	if (clk_get_rate(orion_spi->clk) == 250000000 &&
+			speed == 50000000 && spi->mode & SPI_CPOL &&
+			spi->mode & SPI_CPHA)
+		reg |= ORION_SPI_TMISO_SAMPLE_2;
+	else
+		reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
+
+	writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
+}
+
 /*
  * called only when no transfer is active on the bus
  */
@@ -216,6 +257,9 @@ orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 
 	orion_spi_mode_set(spi);
 
+	if (orion_spi->devdata->is_errata_50mhz_ac)
+		orion_spi_50mhz_ac_timing_erratum(spi, speed);
+
 	rc = orion_spi_baudrate_set(spi, speed);
 	if (rc)
 		return rc;
@@ -413,6 +457,14 @@ static const struct orion_spi_dev armada_375_spi_dev_data = {
 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
 };
 
+static const struct orion_spi_dev armada_380_spi_dev_data = {
+	.typ = ARMADA_SPI,
+	.max_hz = 50000000,
+	.max_divisor = 1920,
+	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
+	.is_errata_50mhz_ac = true,
+};
+
 static const struct of_device_id orion_spi_of_match_table[] = {
 	{
 		.compatible = "marvell,orion-spi",
@@ -428,7 +480,7 @@ static const struct of_device_id orion_spi_of_match_table[] = {
 	},
 	{
 		.compatible = "marvell,armada-380-spi",
-		.data = &armada_xp_spi_dev_data,
+		.data = &armada_380_spi_dev_data,
 	},
 	{
 		.compatible = "marvell,armada-390-spi",
-- 
cgit v1.2.3-54-g00ecf