1 files changed, 214 insertions, 42 deletions

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index babb15f07995..79ddefe4180d 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -53,10 +53,13 @@
 /* generic defines to abstract from the different register layouts */
 #define MXC_INT_RR	(1 << 0) /* Receive data ready interrupt */
 #define MXC_INT_TE	(1 << 1) /* Transmit FIFO empty interrupt */
+#define MXC_INT_RDR	BIT(4) /* Receive date threshold interrupt */
 
 /* The maximum  bytes that a sdma BD can transfer.*/
 #define MAX_SDMA_BD_BYTES  (1 << 15)
 #define MX51_ECSPI_CTRL_MAX_BURST	512
+/* The maximum bytes that IMX53_ECSPI can transfer in slave mode.*/
+#define MX53_MAX_TRANSFER_BYTES		512
 
 enum spi_imx_devtype {
 	IMX1_CSPI,
@@ -76,7 +79,9 @@ struct spi_imx_devtype_data {
 	void (*trigger)(struct spi_imx_data *);
 	int (*rx_available)(struct spi_imx_data *);
 	void (*reset)(struct spi_imx_data *);
+	void (*disable)(struct spi_imx_data *);
 	bool has_dmamode;
+	bool has_slavemode;
 	unsigned int fifo_size;
 	bool dynamic_burst;
 	enum spi_imx_devtype devtype;
@@ -108,6 +113,11 @@ struct spi_imx_data {
 	unsigned int dynamic_burst, read_u32;
 	unsigned int word_mask;
 
+	/* Slave mode */
+	bool slave_mode;
+	bool slave_aborted;
+	unsigned int slave_burst;
+
 	/* DMA */
 	bool usedma;
 	u32 wml;
@@ -221,6 +231,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 	if (!master->dma_rx)
 		return false;
 
+	if (spi_imx->slave_mode)
+		return false;
+
 	bytes_per_word = spi_imx_bytes_per_word(transfer->bits_per_word);
 
 	if (bytes_per_word != 1 && bytes_per_word != 2 && bytes_per_word != 4)
@@ -262,6 +275,7 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_INT		0x10
 #define MX51_ECSPI_INT_TEEN		(1 <<  0)
 #define MX51_ECSPI_INT_RREN		(1 <<  3)
+#define MX51_ECSPI_INT_RDREN		(1 <<  4)
 
 #define MX51_ECSPI_DMA      0x14
 #define MX51_ECSPI_DMA_TX_WML(wml)	((wml) & 0x3f)
@@ -378,6 +392,44 @@ static void spi_imx_buf_tx_swap(struct spi_imx_data *spi_imx)
 		spi_imx_buf_tx_u16(spi_imx);
 }
 
+static void mx53_ecspi_rx_slave(struct spi_imx_data *spi_imx)
+{
+	u32 val = be32_to_cpu(readl(spi_imx->base + MXC_CSPIRXDATA));
+
+	if (spi_imx->rx_buf) {
+		int n_bytes = spi_imx->slave_burst % sizeof(val);
+
+		if (!n_bytes)
+			n_bytes = sizeof(val);
+
+		memcpy(spi_imx->rx_buf,
+		       ((u8 *)&val) + sizeof(val) - n_bytes, n_bytes);
+
+		spi_imx->rx_buf += n_bytes;
+		spi_imx->slave_burst -= n_bytes;
+	}
+}
+
+static void mx53_ecspi_tx_slave(struct spi_imx_data *spi_imx)
+{
+	u32 val = 0;
+	int n_bytes = spi_imx->count % sizeof(val);
+
+	if (!n_bytes)
+		n_bytes = sizeof(val);
+
+	if (spi_imx->tx_buf) {
+		memcpy(((u8 *)&val) + sizeof(val) - n_bytes,
+		       spi_imx->tx_buf, n_bytes);
+		val = cpu_to_be32(val);
+		spi_imx->tx_buf += n_bytes;
+	}
+
+	spi_imx->count -= n_bytes;
+
+	writel(val, spi_imx->base + MXC_CSPITXDATA);
+}
+
 /* MX51 eCSPI */
 static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
 				      unsigned int fspi, unsigned int *fres)
@@ -427,6 +479,9 @@ static void mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
 	if (enable & MXC_INT_RR)
 		val |= MX51_ECSPI_INT_RREN;
 
+	if (enable & MXC_INT_RDR)
+		val |= MX51_ECSPI_INT_RDREN;
+
 	writel(val, spi_imx->base + MX51_ECSPI_INT);
 }
 
@@ -439,6 +494,15 @@ static void mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
 	writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
 }
 
+static void mx51_ecspi_disable(struct spi_imx_data *spi_imx)
+{
+	u32 ctrl;
+
+	ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
+	ctrl &= ~MX51_ECSPI_CTRL_ENABLE;
+	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
+}
+
 static int mx51_ecspi_config(struct spi_device *spi)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
@@ -446,14 +510,11 @@ static int mx51_ecspi_config(struct spi_device *spi)
 	u32 clk = spi_imx->speed_hz, delay, reg;
 	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
 
-	/*
-	 * The hardware seems to have a race condition when changing modes. The
-	 * current assumption is that the selection of the channel arrives
-	 * earlier in the hardware than the mode bits when they are written at
-	 * the same time.
-	 * So set master mode for all channels as we do not support slave mode.
-	 */
-	ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
+	/* set Master or Slave mode */
+	if (spi_imx->slave_mode)
+		ctrl &= ~MX51_ECSPI_CTRL_MODE_MASK;
+	else
+		ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
 
 	/*
 	 * Enable SPI_RDY handling (falling edge/level triggered).
@@ -468,9 +529,22 @@ static int mx51_ecspi_config(struct spi_device *spi)
 	/* set chip select to use */
 	ctrl |= MX51_ECSPI_CTRL_CS(spi->chip_select);
 
-	ctrl |= (spi_imx->bits_per_word - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
+	if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
+		ctrl |= (spi_imx->slave_burst * 8 - 1)
+			<< MX51_ECSPI_CTRL_BL_OFFSET;
+	else
+		ctrl |= (spi_imx->bits_per_word - 1)
+			<< MX51_ECSPI_CTRL_BL_OFFSET;
 
-	cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
+	/*
+	 * eCSPI burst completion by Chip Select signal in Slave mode
+	 * is not functional for imx53 Soc, config SPI burst completed when
+	 * BURST_LENGTH + 1 bits are received
+	 */
+	if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
+		cfg &= ~MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
+	else
+		cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
 
 	if (spi->mode & SPI_CPHA)
 		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
@@ -805,6 +879,7 @@ static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
 	.fifo_size = 8,
 	.has_dmamode = false,
 	.dynamic_burst = false,
+	.has_slavemode = false,
 	.devtype = IMX1_CSPI,
 };
 
@@ -817,6 +892,7 @@ static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
 	.fifo_size = 8,
 	.has_dmamode = false,
 	.dynamic_burst = false,
+	.has_slavemode = false,
 	.devtype = IMX21_CSPI,
 };
 
@@ -830,6 +906,7 @@ static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
 	.fifo_size = 8,
 	.has_dmamode = false,
 	.dynamic_burst = false,
+	.has_slavemode = false,
 	.devtype = IMX27_CSPI,
 };
 
@@ -842,6 +919,7 @@ static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
 	.fifo_size = 8,
 	.has_dmamode = false,
 	.dynamic_burst = false,
+	.has_slavemode = false,
 	.devtype = IMX31_CSPI,
 };
 
@@ -855,6 +933,7 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
 	.fifo_size = 8,
 	.has_dmamode = true,
 	.dynamic_burst = false,
+	.has_slavemode = false,
 	.devtype = IMX35_CSPI,
 };
 
@@ -867,6 +946,8 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.fifo_size = 64,
 	.has_dmamode = true,
 	.dynamic_burst = true,
+	.has_slavemode = true,
+	.disable = mx51_ecspi_disable,
 	.devtype = IMX51_ECSPI,
 };
 
@@ -878,6 +959,8 @@ static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
 	.reset = mx51_ecspi_reset,
 	.fifo_size = 64,
 	.has_dmamode = true,
+	.has_slavemode = true,
+	.disable = mx51_ecspi_disable,
 	.devtype = IMX53_ECSPI,
 };
 
@@ -945,14 +1028,16 @@ static void spi_imx_push(struct spi_imx_data *spi_imx)
 		spi_imx->txfifo++;
 	}
 
-	spi_imx->devtype_data->trigger(spi_imx);
+	if (!spi_imx->slave_mode)
+		spi_imx->devtype_data->trigger(spi_imx);
 }
 
 static irqreturn_t spi_imx_isr(int irq, void *dev_id)
 {
 	struct spi_imx_data *spi_imx = dev_id;
 
-	while (spi_imx->devtype_data->rx_available(spi_imx)) {
+	while (spi_imx->txfifo &&
+	       spi_imx->devtype_data->rx_available(spi_imx)) {
 		spi_imx->rx(spi_imx);
 		spi_imx->txfifo--;
 	}
@@ -1034,7 +1119,7 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 	spi_imx->speed_hz  = t->speed_hz;
 
 	/* Initialize the functions for transfer */
-	if (spi_imx->devtype_data->dynamic_burst) {
+	if (spi_imx->devtype_data->dynamic_burst && !spi_imx->slave_mode) {
 		u32 mask;
 
 		spi_imx->dynamic_burst = 0;
@@ -1078,6 +1163,12 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 			return ret;
 	}
 
+	if (is_imx53_ecspi(spi_imx) && spi_imx->slave_mode) {
+		spi_imx->rx = mx53_ecspi_rx_slave;
+		spi_imx->tx = mx53_ecspi_tx_slave;
+		spi_imx->slave_burst = t->len;
+	}
+
 	spi_imx->devtype_data->config(spi);
 
 	return 0;
@@ -1262,11 +1353,61 @@ static int spi_imx_pio_transfer(struct spi_device *spi,
 	return transfer->len;
 }
 
+static int spi_imx_pio_transfer_slave(struct spi_device *spi,
+				      struct spi_transfer *transfer)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+	int ret = transfer->len;
+
+	if (is_imx53_ecspi(spi_imx) &&
+	    transfer->len > MX53_MAX_TRANSFER_BYTES) {
+		dev_err(&spi->dev, "Transaction too big, max size is %d bytes\n",
+			MX53_MAX_TRANSFER_BYTES);
+		return -EMSGSIZE;
+	}
+
+	spi_imx->tx_buf = transfer->tx_buf;
+	spi_imx->rx_buf = transfer->rx_buf;
+	spi_imx->count = transfer->len;
+	spi_imx->txfifo = 0;
+
+	reinit_completion(&spi_imx->xfer_done);
+	spi_imx->slave_aborted = false;
+
+	spi_imx_push(spi_imx);
+
+	spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE | MXC_INT_RDR);
+
+	if (wait_for_completion_interruptible(&spi_imx->xfer_done) ||
+	    spi_imx->slave_aborted) {
+		dev_dbg(&spi->dev, "interrupted\n");
+		ret = -EINTR;
+	}
+
+	/* ecspi has a HW issue when works in Slave mode,
+	 * after 64 words writtern to TXFIFO, even TXFIFO becomes empty,
+	 * ECSPI_TXDATA keeps shift out the last word data,
+	 * so we have to disable ECSPI when in slave mode after the
+	 * transfer completes
+	 */
+	if (spi_imx->devtype_data->disable)
+		spi_imx->devtype_data->disable(spi_imx);
+
+	return ret;
+}
+
 static int spi_imx_transfer(struct spi_device *spi,
 				struct spi_transfer *transfer)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 
+	/* flush rxfifo before transfer */
+	while (spi_imx->devtype_data->rx_available(spi_imx))
+		spi_imx->rx(spi_imx);
+
+	if (spi_imx->slave_mode)
+		return spi_imx_pio_transfer_slave(spi, transfer);
+
 	if (spi_imx->usedma)
 		return spi_imx_dma_transfer(spi_imx, transfer);
 	else
@@ -1323,6 +1464,16 @@ spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
 	return 0;
 }
 
+static int spi_imx_slave_abort(struct spi_master *master)
+{
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+	spi_imx->slave_aborted = true;
+	complete(&spi_imx->xfer_done);
+
+	return 0;
+}
+
 static int spi_imx_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -1334,13 +1485,23 @@ static int spi_imx_probe(struct platform_device *pdev)
 	struct spi_imx_data *spi_imx;
 	struct resource *res;
 	int i, ret, irq, spi_drctl;
+	const struct spi_imx_devtype_data *devtype_data = of_id ? of_id->data :
+		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+	bool slave_mode;
 
 	if (!np && !mxc_platform_info) {
 		dev_err(&pdev->dev, "can't get the platform data\n");
 		return -EINVAL;
 	}
 
-	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
+	slave_mode = devtype_data->has_slavemode &&
+			of_property_read_bool(np, "spi-slave");
+	if (slave_mode)
+		master = spi_alloc_slave(&pdev->dev,
+					 sizeof(struct spi_imx_data));
+	else
+		master = spi_alloc_master(&pdev->dev,
+					  sizeof(struct spi_imx_data));
 	if (!master)
 		return -ENOMEM;
 
@@ -1358,20 +1519,29 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx = spi_master_get_devdata(master);
 	spi_imx->bitbang.master = master;
 	spi_imx->dev = &pdev->dev;
+	spi_imx->slave_mode = slave_mode;
 
-	spi_imx->devtype_data = of_id ? of_id->data :
-		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+	spi_imx->devtype_data = devtype_data;
 
+	/* Get number of chip selects, either platform data or OF */
 	if (mxc_platform_info) {
 		master->num_chipselect = mxc_platform_info->num_chipselect;
-		master->cs_gpios = devm_kzalloc(&master->dev,
-			sizeof(int) * master->num_chipselect, GFP_KERNEL);
-		if (!master->cs_gpios)
-			return -ENOMEM;
+		if (mxc_platform_info->chipselect) {
+			master->cs_gpios = devm_kzalloc(&master->dev,
+				sizeof(int) * master->num_chipselect, GFP_KERNEL);
+			if (!master->cs_gpios)
+				return -ENOMEM;
+
+			for (i = 0; i < master->num_chipselect; i++)
+				master->cs_gpios[i] = mxc_platform_info->chipselect[i];
+		}
+	} else {
+		u32 num_cs;
 
-		for (i = 0; i < master->num_chipselect; i++)
-			master->cs_gpios[i] = mxc_platform_info->chipselect[i];
- 	}
+		if (!of_property_read_u32(np, "num-cs", &num_cs))
+			master->num_chipselect = num_cs;
+		/* If not preset, default value of 1 is used */
+	}
 
 	spi_imx->bitbang.chipselect = spi_imx_chipselect;
 	spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
@@ -1380,6 +1550,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
 	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
 	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
+	spi_imx->bitbang.master->slave_abort = spi_imx_slave_abort;
 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
 					     | SPI_NO_CS;
 	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) ||
@@ -1451,37 +1622,38 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx->devtype_data->intctrl(spi_imx, 0);
 
 	master->dev.of_node = pdev->dev.of_node;
+
+	/* Request GPIO CS lines, if any */
+	if (!spi_imx->slave_mode && master->cs_gpios) {
+		for (i = 0; i < master->num_chipselect; i++) {
+			if (!gpio_is_valid(master->cs_gpios[i]))
+				continue;
+
+			ret = devm_gpio_request(&pdev->dev,
+						master->cs_gpios[i],
+						DRIVER_NAME);
+			if (ret) {
+				dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
+					master->cs_gpios[i]);
+				goto out_spi_bitbang;
+			}
+		}
+	}
+
 	ret = spi_bitbang_start(&spi_imx->bitbang);
 	if (ret) {
 		dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
 		goto out_clk_put;
 	}
 
-	if (!master->cs_gpios) {
-		dev_err(&pdev->dev, "No CS GPIOs available\n");
-		ret = -EINVAL;
-		goto out_clk_put;
-	}
-
-	for (i = 0; i < master->num_chipselect; i++) {
-		if (!gpio_is_valid(master->cs_gpios[i]))
-			continue;
-
-		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
-					DRIVER_NAME);
-		if (ret) {
-			dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
-				master->cs_gpios[i]);
-			goto out_clk_put;
-		}
-	}
-
 	dev_info(&pdev->dev, "probed\n");
 
 	clk_disable(spi_imx->clk_ipg);
 	clk_disable(spi_imx->clk_per);
 	return ret;
 
+out_spi_bitbang:
+	spi_bitbang_stop(&spi_imx->bitbang);
 out_clk_put:
 	clk_disable_unprepare(spi_imx->clk_ipg);
 out_put_per: