[PATCH 0/2 v4] SPI: spi-pxa2xx: Add support for Intel Quark X1000 SPI controller

[PATCH 0/2 v4] SPI: spi-pxa2xx: Add support for Intel Quark X1000 SPI controller

[Weike Chen]

Hi,
Intel Quark X1000 consists of two SPI controllers which can be PCI enumerated.
SPI-PXA2XX PCI layer doesn't support it. Thus, we add support for Intel Quark
X1000 SPI as well.

---
v4:
[PATCH 1/2]
* No changes.
[PATCH 2/2]
* Move all Quark specific macros out of #ifdef 'CONFIG_ARCH_PXA'.

v3:
[PATCH 1/2]
* Improve the commit message.
* A couple of minor fixes.
[PATCH 2/2]
* Set '.num_chipselect' to '1' instead of '4'.
* A couple of minor fixes.

v2:
  Split into two patches: one is for helper functions,
  and another is for quark supporting.

[PATCH 1/2]
* Add helper functions to access registers.
* Use 'switch' instead of 'if-else'.
[PATCH 2/2]
* Use 'switch' instead of 'if-else'.
* Add comments for the 'dds'&'clk_div' caculation.
* A couple of minor fixes.

Weike Chen (2):
  SPI: spi-pxa2xx: Add helpers for regiseters' accessing
  SPI: spi-pxa2xx: SPI support for Intel Quark X1000

 drivers/spi/spi-pxa2xx-pci.c |    8 ++
 drivers/spi/spi-pxa2xx.c     |  304 ++++++++++++++++++++++++++++++++++++------
 drivers/spi/spi-pxa2xx.h     |   16 ++-
 include/linux/pxa2xx_ssp.h   |   20 +++
 4 files changed, 303 insertions(+), 45 deletions(-)

-- 
1.7.9.5

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[PATCH 1/2 v4] SPI: spi-pxa2xx: Add helpers for regiseters' accessing

[Weike Chen]

There are several registers for SPI, and the registers of 'SSCR0' and 'SSCR1'
are accessed frequently. This path is to introduce helper functions to
simplify the accessing of 'SSCR0' and 'SSCR1'.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Weike Chen <alvin.chen@intel.com>
---
 drivers/spi/spi-pxa2xx.c |  107 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 84 insertions(+), 23 deletions(-)

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index d8a105f..770b581 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -80,6 +80,73 @@ static bool is_lpss_ssp(const struct driver_data *drv_data)
 	return drv_data->ssp_type == LPSS_SSP;
 }
 
+static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
+{
+	switch (drv_data->ssp_type) {
+	default:
+		return SSCR1_CHANGE_MASK;
+	}
+}
+
+static u32
+pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
+{
+	switch (drv_data->ssp_type) {
+	default:
+		return RX_THRESH_DFLT;
+	}
+}
+
+static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+	u32 mask;
+
+	switch (drv_data->ssp_type) {
+	default:
+		mask = SSSR_TFL_MASK;
+		break;
+	}
+
+	return (read_SSSR(reg) & mask) == mask;
+}
+
+static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
+				     u32 *sccr1_reg)
+{
+	u32 mask;
+
+	switch (drv_data->ssp_type) {
+	default:
+		mask = SSCR1_RFT;
+		break;
+	}
+	*sccr1_reg &= ~mask;
+}
+
+static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
+				   u32 *sccr1_reg, u32 threshold)
+{
+	switch (drv_data->ssp_type) {
+	default:
+		*sccr1_reg |= SSCR1_RxTresh(threshold);
+		break;
+	}
+}
+
+static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
+				  u32 clk_div, u8 bits)
+{
+	switch (drv_data->ssp_type) {
+	default:
+		return clk_div
+			| SSCR0_Motorola
+			| SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
+			| SSCR0_SSE
+			| (bits > 16 ? SSCR0_EDSS : 0);
+	}
+}
+
 /*
  * Read and write LPSS SSP private registers. Caller must first check that
  * is_lpss_ssp() returns true before these can be called.
@@ -234,7 +301,7 @@ static int null_writer(struct driver_data *drv_data)
 	void __iomem *reg = drv_data->ioaddr;
 	u8 n_bytes = drv_data->n_bytes;
 
-	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+	if (pxa2xx_spi_txfifo_full(drv_data)
 		|| (drv_data->tx == drv_data->tx_end))
 		return 0;
 
@@ -262,7 +329,7 @@ static int u8_writer(struct driver_data *drv_data)
 {
 	void __iomem *reg = drv_data->ioaddr;
 
-	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+	if (pxa2xx_spi_txfifo_full(drv_data)
 		|| (drv_data->tx == drv_data->tx_end))
 		return 0;
 
@@ -289,7 +356,7 @@ static int u16_writer(struct driver_data *drv_data)
 {
 	void __iomem *reg = drv_data->ioaddr;
 
-	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+	if (pxa2xx_spi_txfifo_full(drv_data)
 		|| (drv_data->tx == drv_data->tx_end))
 		return 0;
 
@@ -316,7 +383,7 @@ static int u32_writer(struct driver_data *drv_data)
 {
 	void __iomem *reg = drv_data->ioaddr;
 
-	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+	if (pxa2xx_spi_txfifo_full(drv_data)
 		|| (drv_data->tx == drv_data->tx_end))
 		return 0;
 
@@ -508,8 +575,9 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 		 * remaining RX bytes.
 		 */
 		if (pxa25x_ssp_comp(drv_data)) {
+			u32 rx_thre;
 
-			sccr1_reg &= ~SSCR1_RFT;
+			pxa2xx_spi_clear_rx_thre(drv_data, &sccr1_reg);
 
 			bytes_left = drv_data->rx_end - drv_data->rx;
 			switch (drv_data->n_bytes) {
@@ -519,10 +587,11 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 				bytes_left >>= 1;
 			}
 
-			if (bytes_left > RX_THRESH_DFLT)
-				bytes_left = RX_THRESH_DFLT;
+			rx_thre = pxa2xx_spi_get_rx_default_thre(drv_data);
+			if (rx_thre > bytes_left)
+				rx_thre = bytes_left;
 
-			sccr1_reg |= SSCR1_RxTresh(bytes_left);
+			pxa2xx_spi_set_rx_thre(drv_data, &sccr1_reg, rx_thre);
 		}
 		write_SSCR1(sccr1_reg, reg);
 	}
@@ -613,6 +682,7 @@ static void pump_transfers(unsigned long data)
 	u32 cr1;
 	u32 dma_thresh = drv_data->cur_chip->dma_threshold;
 	u32 dma_burst = drv_data->cur_chip->dma_burst_size;
+	u32 change_mask = pxa2xx_spi_get_ssrc1_change_mask(drv_data);
 
 	/* Get current state information */
 	message = drv_data->cur_msg;
@@ -731,11 +801,7 @@ static void pump_transfers(unsigned long data)
 						     "pump_transfers: DMA burst size reduced to match bits_per_word\n");
 		}
 
-		cr0 = clk_div
-			| SSCR0_Motorola
-			| SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
-			| SSCR0_SSE
-			| (bits > 16 ? SSCR0_EDSS : 0);
+		cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
 	}
 
 	message->state = RUNNING_STATE;
@@ -772,16 +838,15 @@ static void pump_transfers(unsigned long data)
 	}
 
 	/* see if we need to reload the config registers */
-	if ((read_SSCR0(reg) != cr0)
-		|| (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
-			(cr1 & SSCR1_CHANGE_MASK)) {
+	if ((read_SSCR0(reg) != cr0) ||
+	    (read_SSCR1(reg) & change_mask) != (cr1 & change_mask)) {
 
 		/* stop the SSP, and update the other bits */
 		write_SSCR0(cr0 & ~SSCR0_SSE, reg);
 		if (!pxa25x_ssp_comp(drv_data))
 			write_SSTO(chip->timeout, reg);
 		/* first set CR1 without interrupt and service enables */
-		write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg);
+		write_SSCR1(cr1 & change_mask, reg);
 		/* restart the SSP */
 		write_SSCR0(cr0, reg);
 
@@ -959,12 +1024,8 @@ static int setup(struct spi_device *spi)
 	clk_div = ssp_get_clk_div(drv_data, spi->max_speed_hz);
 	chip->speed_hz = spi->max_speed_hz;
 
-	chip->cr0 = clk_div
-			| SSCR0_Motorola
-			| SSCR0_DataSize(spi->bits_per_word > 16 ?
-				spi->bits_per_word - 16 : spi->bits_per_word)
-			| SSCR0_SSE
-			| (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
+	chip->cr0 = pxa2xx_configure_sscr0(drv_data, clk_div,
+					   spi->bits_per_word);
 	chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
 	chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
 			| (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
-- 
1.7.9.5

[PATCH 2/2 v4] SPI: spi-pxa2xx: SPI support for Intel Quark X1000

[Weike Chen]

There are two SPI controllers exported by PCI subsystem for Intel Quark X1000.
The SPI memory mapped I/O registers supported by Quark are different from
the current implementation, and Quark only supports the registers of 'SSCR0',
'SSCR1', 'SSSR', 'SSDR', and 'DDS_RATE'. This patch is to enable the SPI for
Intel Quark X1000.

This piece of work is derived from Dan O'Donovan's initial work for Intel Quark
X1000 SPI enabling.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Weike Chen <alvin.chen@intel.com>
---
 drivers/spi/spi-pxa2xx-pci.c |    8 ++
 drivers/spi/spi-pxa2xx.c     |  197 ++++++++++++++++++++++++++++++++++++++----
 drivers/spi/spi-pxa2xx.h     |   16 ++--
 include/linux/pxa2xx_ssp.h   |   20 +++++
 4 files changed, 219 insertions(+), 22 deletions(-)

diff --git a/drivers/spi/spi-pxa2xx-pci.c b/drivers/spi/spi-pxa2xx-pci.c
index 6beee8c..fa7399e 100644
--- a/drivers/spi/spi-pxa2xx-pci.c
+++ b/drivers/spi/spi-pxa2xx-pci.c
@@ -19,6 +19,7 @@ enum {
 	PORT_BSW0,
 	PORT_BSW1,
 	PORT_BSW2,
+	PORT_QUARK_X1000,
 };
 
 struct pxa_spi_info {
@@ -92,6 +93,12 @@ static struct pxa_spi_info spi_info_configs[] = {
 		.tx_param = &bsw2_tx_param,
 		.rx_param = &bsw2_rx_param,
 	},
+	[PORT_QUARK_X1000] = {
+		.type = QUARK_X1000_SSP,
+		.port_id = -1,
+		.num_chipselect = 1,
+		.max_clk_rate = 50000000,
+	},
 };
 
 static int pxa2xx_spi_pci_probe(struct pci_dev *dev,
@@ -191,6 +198,7 @@ static void pxa2xx_spi_pci_remove(struct pci_dev *dev)
 
 static const struct pci_device_id pxa2xx_spi_pci_devices[] = {
 	{ PCI_VDEVICE(INTEL, 0x2e6a), PORT_CE4100 },
+	{ PCI_VDEVICE(INTEL, 0x0935), PORT_QUARK_X1000 },
 	{ PCI_VDEVICE(INTEL, 0x0f0e), PORT_BYT },
 	{ PCI_VDEVICE(INTEL, 0x228e), PORT_BSW0 },
 	{ PCI_VDEVICE(INTEL, 0x2290), PORT_BSW1 },
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 770b581..d8ed3e0 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -63,10 +63,64 @@ MODULE_ALIAS("platform:pxa2xx-spi");
 				| SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
 				| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
 
+#define QUARK_X1000_SSCR1_CHANGE_MASK (QUARK_X1000_SSCR1_STRF	\
+				| QUARK_X1000_SSCR1_EFWR	\
+				| QUARK_X1000_SSCR1_RFT		\
+				| QUARK_X1000_SSCR1_TFT		\
+				| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+
 #define LPSS_RX_THRESH_DFLT	64
 #define LPSS_TX_LOTHRESH_DFLT	160
 #define LPSS_TX_HITHRESH_DFLT	224
 
+struct quark_spi_rate {
+	u32 bitrate;
+	u32 dds_clk_rate;
+	u32 clk_div;
+};
+
+/*
+ * 'rate', 'dds', 'clk_div' lookup table, which is defined in
+ * the Quark SPI datasheet.
+ */
+static const struct quark_spi_rate quark_spi_rate_table[] = {
+/*	bitrate,	dds_clk_rate,	clk_div */
+	{50000000,	0x800000,	0},
+	{40000000,	0x666666,	0},
+	{25000000,	0x400000,	0},
+	{20000000,	0x666666,	1},
+	{16667000,	0x800000,	2},
+	{13333000,	0x666666,	2},
+	{12500000,	0x200000,	0},
+	{10000000,	0x800000,	4},
+	{8000000,	0x666666,	4},
+	{6250000,	0x400000,	3},
+	{5000000,	0x400000,	4},
+	{4000000,	0x666666,	9},
+	{3125000,	0x80000,	0},
+	{2500000,	0x400000,	9},
+	{2000000,	0x666666,	19},
+	{1563000,	0x40000,	0},
+	{1250000,	0x200000,	9},
+	{1000000,	0x400000,	24},
+	{800000,	0x666666,	49},
+	{781250,	0x20000,	0},
+	{625000,	0x200000,	19},
+	{500000,	0x400000,	49},
+	{400000,	0x666666,	99},
+	{390625,	0x10000,	0},
+	{250000,	0x400000,	99},
+	{200000,	0x666666,	199},
+	{195313,	0x8000,		0},
+	{125000,	0x100000,	49},
+	{100000,	0x200000,	124},
+	{50000,		0x100000,	124},
+	{25000,		0x80000,	124},
+	{10016,		0x20000,	77},
+	{5040,		0x20000,	154},
+	{1002,		0x8000,		194},
+};
+
 /* Offset from drv_data->lpss_base */
 #define GENERAL_REG		0x08
 #define GENERAL_REG_RXTO_HOLDOFF_DISABLE BIT(24)
@@ -80,9 +134,16 @@ static bool is_lpss_ssp(const struct driver_data *drv_data)
 	return drv_data->ssp_type == LPSS_SSP;
 }
 
+static bool is_quark_x1000_ssp(const struct driver_data *drv_data)
+{
+	return drv_data->ssp_type == QUARK_X1000_SSP;
+}
+
 static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
 {
 	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		return QUARK_X1000_SSCR1_CHANGE_MASK;
 	default:
 		return SSCR1_CHANGE_MASK;
 	}
@@ -92,6 +153,8 @@ static u32
 pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
 {
 	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		return RX_THRESH_QUARK_X1000_DFLT;
 	default:
 		return RX_THRESH_DFLT;
 	}
@@ -103,6 +166,9 @@ static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
 	u32 mask;
 
 	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		mask = QUARK_X1000_SSSR_TFL_MASK;
+		break;
 	default:
 		mask = SSSR_TFL_MASK;
 		break;
@@ -117,6 +183,9 @@ static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
 	u32 mask;
 
 	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		mask = QUARK_X1000_SSCR1_RFT;
+		break;
 	default:
 		mask = SSCR1_RFT;
 		break;
@@ -128,6 +197,9 @@ static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
 				   u32 *sccr1_reg, u32 threshold)
 {
 	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		*sccr1_reg |= QUARK_X1000_SSCR1_RxTresh(threshold);
+		break;
 	default:
 		*sccr1_reg |= SSCR1_RxTresh(threshold);
 		break;
@@ -138,6 +210,11 @@ static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
 				  u32 clk_div, u8 bits)
 {
 	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		return clk_div
+			| QUARK_X1000_SSCR0_Motorola
+			| QUARK_X1000_SSCR0_DataSize(bits > 32 ? 8 : bits)
+			| SSCR0_SSE;
 	default:
 		return clk_div
 			| SSCR0_Motorola
@@ -654,6 +731,28 @@ static irqreturn_t ssp_int(int irq, void *dev_id)
 	return drv_data->transfer_handler(drv_data);
 }
 
+/*
+ * The Quark SPI data sheet gives a table, and for the given 'rate',
+ * the 'dds' and 'clk_div' can be found in the table.
+ */
+static u32 quark_x1000_set_clk_regvals(u32 rate, u32 *dds, u32 *clk_div)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(quark_spi_rate_table); i++) {
+		if (rate >= quark_spi_rate_table[i].bitrate) {
+			*dds = quark_spi_rate_table[i].dds_clk_rate;
+			*clk_div = quark_spi_rate_table[i].clk_div;
+			return quark_spi_rate_table[i].bitrate;
+		}
+	}
+
+	*dds = quark_spi_rate_table[i-1].dds_clk_rate;
+	*clk_div = quark_spi_rate_table[i-1].clk_div;
+
+	return quark_spi_rate_table[i-1].bitrate;
+}
+
 static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
 {
 	unsigned long ssp_clk = drv_data->max_clk_rate;
@@ -667,6 +766,20 @@ static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
 		return ((ssp_clk / rate - 1) & 0xfff) << 8;
 }
 
+static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data,
+					   struct chip_data *chip, int rate)
+{
+	u32 clk_div;
+
+	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		quark_x1000_set_clk_regvals(rate, &chip->dds_rate, &clk_div);
+		return clk_div << 8;
+	default:
+		return ssp_get_clk_div(drv_data, rate);
+	}
+}
+
 static void pump_transfers(unsigned long data)
 {
 	struct driver_data *drv_data = (struct driver_data *)data;
@@ -769,7 +882,7 @@ static void pump_transfers(unsigned long data)
 		if (transfer->bits_per_word)
 			bits = transfer->bits_per_word;
 
-		clk_div = ssp_get_clk_div(drv_data, speed);
+		clk_div = pxa2xx_ssp_get_clk_div(drv_data, chip, speed);
 
 		if (bits <= 8) {
 			drv_data->n_bytes = 1;
@@ -837,6 +950,10 @@ static void pump_transfers(unsigned long data)
 			write_SSITF(chip->lpss_tx_threshold, reg);
 	}
 
+	if (is_quark_x1000_ssp(drv_data) &&
+	    (read_DDS_RATE(reg) != chip->dds_rate))
+		write_DDS_RATE(chip->dds_rate, reg);
+
 	/* see if we need to reload the config registers */
 	if ((read_SSCR0(reg) != cr0) ||
 	    (read_SSCR1(reg) & change_mask) != (cr1 & change_mask)) {
@@ -940,14 +1057,22 @@ static int setup(struct spi_device *spi)
 	unsigned int clk_div;
 	uint tx_thres, tx_hi_thres, rx_thres;
 
-	if (is_lpss_ssp(drv_data)) {
+	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		tx_thres = TX_THRESH_QUARK_X1000_DFLT;
+		tx_hi_thres = 0;
+		rx_thres = RX_THRESH_QUARK_X1000_DFLT;
+		break;
+	case LPSS_SSP:
 		tx_thres = LPSS_TX_LOTHRESH_DFLT;
 		tx_hi_thres = LPSS_TX_HITHRESH_DFLT;
 		rx_thres = LPSS_RX_THRESH_DFLT;
-	} else {
+		break;
+	default:
 		tx_thres = TX_THRESH_DFLT;
 		tx_hi_thres = 0;
 		rx_thres = RX_THRESH_DFLT;
+		break;
 	}
 
 	/* Only alloc on first setup */
@@ -1000,9 +1125,6 @@ static int setup(struct spi_device *spi)
 		chip->enable_dma = drv_data->master_info->enable_dma;
 	}
 
-	chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
-			(SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
-
 	chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
 	chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres)
 				| SSITF_TxHiThresh(tx_hi_thres);
@@ -1021,11 +1143,24 @@ static int setup(struct spi_device *spi)
 		}
 	}
 
-	clk_div = ssp_get_clk_div(drv_data, spi->max_speed_hz);
+	clk_div = pxa2xx_ssp_get_clk_div(drv_data, chip, spi->max_speed_hz);
 	chip->speed_hz = spi->max_speed_hz;
 
 	chip->cr0 = pxa2xx_configure_sscr0(drv_data, clk_div,
 					   spi->bits_per_word);
+	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		chip->threshold = (QUARK_X1000_SSCR1_RxTresh(rx_thres)
+				   & QUARK_X1000_SSCR1_RFT)
+				   | (QUARK_X1000_SSCR1_TxTresh(tx_thres)
+				   & QUARK_X1000_SSCR1_TFT);
+		break;
+	default:
+		chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
+			(SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
+		break;
+	}
+
 	chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
 	chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
 			| (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
@@ -1054,7 +1189,8 @@ static int setup(struct spi_device *spi)
 		chip->read = u16_reader;
 		chip->write = u16_writer;
 	} else if (spi->bits_per_word <= 32) {
-		chip->cr0 |= SSCR0_EDSS;
+		if (!is_quark_x1000_ssp(drv_data))
+			chip->cr0 |= SSCR0_EDSS;
 		chip->n_bytes = 4;
 		chip->read = u32_reader;
 		chip->write = u32_writer;
@@ -1205,7 +1341,15 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 	drv_data->ioaddr = ssp->mmio_base;
 	drv_data->ssdr_physical = ssp->phys_base + SSDR;
 	if (pxa25x_ssp_comp(drv_data)) {
-		master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
+		switch (drv_data->ssp_type) {
+		case QUARK_X1000_SSP:
+			master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
+			break;
+		default:
+			master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
+			break;
+		}
+
 		drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
 		drv_data->dma_cr1 = 0;
 		drv_data->clear_sr = SSSR_ROR;
@@ -1243,16 +1387,35 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 
 	/* Load default SSP configuration */
 	write_SSCR0(0, drv_data->ioaddr);
-	write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
-				SSCR1_TxTresh(TX_THRESH_DFLT),
-				drv_data->ioaddr);
-	write_SSCR0(SSCR0_SCR(2)
-			| SSCR0_Motorola
-			| SSCR0_DataSize(8),
-			drv_data->ioaddr);
+	switch (drv_data->ssp_type) {
+	case QUARK_X1000_SSP:
+		write_SSCR1(QUARK_X1000_SSCR1_RxTresh(
+					RX_THRESH_QUARK_X1000_DFLT) |
+			    QUARK_X1000_SSCR1_TxTresh(
+					TX_THRESH_QUARK_X1000_DFLT),
+			    drv_data->ioaddr);
+
+		/* using the Motorola SPI protocol and use 8 bit frame */
+		write_SSCR0(QUARK_X1000_SSCR0_Motorola
+			    | QUARK_X1000_SSCR0_DataSize(8),
+			    drv_data->ioaddr);
+		break;
+	default:
+		write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
+			    SSCR1_TxTresh(TX_THRESH_DFLT),
+			    drv_data->ioaddr);
+		write_SSCR0(SSCR0_SCR(2)
+			    | SSCR0_Motorola
+			    | SSCR0_DataSize(8),
+			    drv_data->ioaddr);
+		break;
+	}
+
 	if (!pxa25x_ssp_comp(drv_data))
 		write_SSTO(0, drv_data->ioaddr);
-	write_SSPSP(0, drv_data->ioaddr);
+
+	if (!is_quark_x1000_ssp(drv_data))
+		write_SSPSP(0, drv_data->ioaddr);
 
 	lpss_ssp_setup(drv_data);
 
diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h
index 5adc2a1..6bec59c 100644
--- a/drivers/spi/spi-pxa2xx.h
+++ b/drivers/spi/spi-pxa2xx.h
@@ -93,6 +93,7 @@ struct driver_data {
 struct chip_data {
 	u32 cr0;
 	u32 cr1;
+	u32 dds_rate;
 	u32 psp;
 	u32 timeout;
 	u8 n_bytes;
@@ -126,6 +127,7 @@ DEFINE_SSP_REG(SSCR1, 0x04)
 DEFINE_SSP_REG(SSSR, 0x08)
 DEFINE_SSP_REG(SSITR, 0x0c)
 DEFINE_SSP_REG(SSDR, 0x10)
+DEFINE_SSP_REG(DDS_RATE, 0x28)  /* DDS Clock Rate */
 DEFINE_SSP_REG(SSTO, 0x28)
 DEFINE_SSP_REG(SSPSP, 0x2c)
 DEFINE_SSP_REG(SSITF, SSITF)
@@ -141,18 +143,22 @@ DEFINE_SSP_REG(SSIRF, SSIRF)
 
 static inline int pxa25x_ssp_comp(struct driver_data *drv_data)
 {
-	if (drv_data->ssp_type == PXA25x_SSP)
+	switch (drv_data->ssp_type) {
+	case PXA25x_SSP:
+	case CE4100_SSP:
+	case QUARK_X1000_SSP:
 		return 1;
-	if (drv_data->ssp_type == CE4100_SSP)
-		return 1;
-	return 0;
+	default:
+		return 0;
+	}
 }
 
 static inline void write_SSSR_CS(struct driver_data *drv_data, u32 val)
 {
 	void __iomem *reg = drv_data->ioaddr;
 
-	if (drv_data->ssp_type == CE4100_SSP)
+	if (drv_data->ssp_type == CE4100_SSP ||
+	    drv_data->ssp_type == QUARK_X1000_SSP)
 		val |= read_SSSR(reg) & SSSR_ALT_FRM_MASK;
 
 	write_SSSR(val, reg);
diff --git a/include/linux/pxa2xx_ssp.h b/include/linux/pxa2xx_ssp.h
index f2b4051..77aed9e 100644
--- a/include/linux/pxa2xx_ssp.h
+++ b/include/linux/pxa2xx_ssp.h
@@ -108,6 +108,25 @@
 #define SSCR1_RxTresh(x) (((x) - 1) << 10) /* level [1..4] */
 #endif
 
+/* QUARK_X1000 SSCR0 bit definition */
+#define QUARK_X1000_SSCR0_DSS	(0x1F)		/* Data Size Select (mask) */
+#define QUARK_X1000_SSCR0_DataSize(x)  ((x) - 1)	/* Data Size Select [4..32] */
+#define QUARK_X1000_SSCR0_FRF	(0x3 << 5)	/* FRame Format (mask) */
+#define QUARK_X1000_SSCR0_Motorola	(0x0 << 5)	/* Motorola's Serial Peripheral Interface (SPI) */
+
+#define RX_THRESH_QUARK_X1000_DFLT	1
+#define TX_THRESH_QUARK_X1000_DFLT	16
+
+#define QUARK_X1000_SSSR_TFL_MASK	(0x1F << 8)	/* Transmit FIFO Level mask */
+#define QUARK_X1000_SSSR_RFL_MASK	(0x1F << 13)	/* Receive FIFO Level mask */
+
+#define QUARK_X1000_SSCR1_TFT	(0x1F << 6)	/* Transmit FIFO Threshold (mask) */
+#define QUARK_X1000_SSCR1_TxTresh(x) (((x) - 1) << 6)	/* level [1..32] */
+#define QUARK_X1000_SSCR1_RFT	(0x1F << 11)	/* Receive FIFO Threshold (mask) */
+#define QUARK_X1000_SSCR1_RxTresh(x) (((x) - 1) << 11)	/* level [1..32] */
+#define QUARK_X1000_SSCR1_STRF       (1 << 17)		/* Select FIFO or EFWR */
+#define QUARK_X1000_SSCR1_EFWR	(1 << 16)		/* Enable FIFO Write/Read */
+
 /* extra bits in PXA255, PXA26x and PXA27x SSP ports */
 #define SSCR0_TISSP		(1 << 4)	/* TI Sync Serial Protocol */
 #define SSCR0_PSP		(3 << 4)	/* PSP - Programmable Serial Protocol */
@@ -175,6 +194,7 @@ enum pxa_ssp_type {
 	PXA910_SSP,
 	CE4100_SSP,
 	LPSS_SSP,
+	QUARK_X1000_SSP,
 };
 
 struct ssp_device {
-- 
1.7.9.5

Re: [PATCH 2/2 v4] SPI: spi-pxa2xx: SPI support for Intel Quark X1000

[Mark Brown]

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On Wed, Nov 26, 2014 at 02:35:10AM -0800, Weike Chen wrote:
> There are two SPI controllers exported by PCI subsystem for Intel Quark X1000.
> The SPI memory mapped I/O registers supported by Quark are different from
> the current implementation, and Quark only supports the registers of 'SSCR0',
> 'SSCR1', 'SSSR', 'SSDR', and 'DDS_RATE'. This patch is to enable the SPI for
> Intel Quark X1000.

Applied, thanks.  Please use subject lines matching the style for the
subsystem.

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