1 files changed, 105 insertions, 23 deletions

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index fcd261f98b9f..c5dcfb434a49 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -19,6 +19,7 @@
 #include <linux/dmaengine.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -55,9 +56,14 @@ struct sh_msiof_spi_priv {
 	void *rx_dma_page;
 	dma_addr_t tx_dma_addr;
 	dma_addr_t rx_dma_addr;
+	unsigned short unused_ss;
+	bool native_cs_inited;
+	bool native_cs_high;
 	bool slave_aborted;
 };
 
+#define MAX_SS	3	/* Maximum number of native chip selects */
+
 #define TMDR1	0x00	/* Transmit Mode Register 1 */
 #define TMDR2	0x04	/* Transmit Mode Register 2 */
 #define TMDR3	0x08	/* Transmit Mode Register 3 */
@@ -91,6 +97,8 @@ struct sh_msiof_spi_priv {
 #define MDR1_XXSTP	 0x00000001 /* Transmission/Reception Stop on FIFO */
 /* TMDR1 */
 #define TMDR1_PCON	 0x40000000 /* Transfer Signal Connection */
+#define TMDR1_SYNCCH_MASK 0xc000000 /* Synchronization Signal Channel Select */
+#define TMDR1_SYNCCH_SHIFT	 26 /* 0=MSIOF_SYNC, 1=MSIOF_SS1, 2=MSIOF_SS2 */
 
 /* TMDR2 and RMDR2 */
 #define MDR2_BITLEN1(i)	(((i) - 1) << 24) /* Data Size (8-32 bits) */
@@ -324,7 +332,7 @@ static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
 	return val;
 }
 
-static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
+static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p, u32 ss,
 				      u32 cpol, u32 cpha,
 				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
 {
@@ -342,10 +350,13 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
 	tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
 	tmp |= lsb_first << MDR1_BITLSB_SHIFT;
 	tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
-	if (spi_controller_is_slave(p->master))
+	if (spi_controller_is_slave(p->master)) {
 		sh_msiof_write(p, TMDR1, tmp | TMDR1_PCON);
-	else
-		sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
+	} else {
+		sh_msiof_write(p, TMDR1,
+			       tmp | MDR1_TRMD | TMDR1_PCON |
+			       (ss < MAX_SS ? ss : 0) << TMDR1_SYNCCH_SHIFT);
+	}
 	if (p->master->flags & SPI_MASTER_MUST_TX) {
 		/* These bits are reserved if RX needs TX */
 		tmp &= ~0x0000ffff;
@@ -528,8 +539,7 @@ static int sh_msiof_spi_setup(struct spi_device *spi)
 {
 	struct device_node	*np = spi->master->dev.of_node;
 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
-
-	pm_runtime_get_sync(&p->pdev->dev);
+	u32 clr, set, tmp;
 
 	if (!np) {
 		/*
@@ -539,19 +549,31 @@ static int sh_msiof_spi_setup(struct spi_device *spi)
 		spi->cs_gpio = (uintptr_t)spi->controller_data;
 	}
 
-	/* Configure pins before deasserting CS */
-	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
-				  !!(spi->mode & SPI_CPHA),
-				  !!(spi->mode & SPI_3WIRE),
-				  !!(spi->mode & SPI_LSB_FIRST),
-				  !!(spi->mode & SPI_CS_HIGH));
+	if (gpio_is_valid(spi->cs_gpio)) {
+		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
+		return 0;
+	}
 
-	if (spi->cs_gpio >= 0)
-		gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
+	if (spi_controller_is_slave(p->master))
+		return 0;
 
+	if (p->native_cs_inited &&
+	    (p->native_cs_high == !!(spi->mode & SPI_CS_HIGH)))
+		return 0;
 
+	/* Configure native chip select mode/polarity early */
+	clr = MDR1_SYNCMD_MASK;
+	set = MDR1_TRMD | TMDR1_PCON | MDR1_SYNCMD_SPI;
+	if (spi->mode & SPI_CS_HIGH)
+		clr |= BIT(MDR1_SYNCAC_SHIFT);
+	else
+		set |= BIT(MDR1_SYNCAC_SHIFT);
+	pm_runtime_get_sync(&p->pdev->dev);
+	tmp = sh_msiof_read(p, TMDR1) & ~clr;
+	sh_msiof_write(p, TMDR1, tmp | set);
 	pm_runtime_put(&p->pdev->dev);
-
+	p->native_cs_high = spi->mode & SPI_CS_HIGH;
+	p->native_cs_inited = true;
 	return 0;
 }
 
@@ -560,13 +582,20 @@ static int sh_msiof_prepare_message(struct spi_master *master,
 {
 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
 	const struct spi_device *spi = msg->spi;
+	u32 ss, cs_high;
 
 	/* Configure pins before asserting CS */
-	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
+	if (gpio_is_valid(spi->cs_gpio)) {
+		ss = p->unused_ss;
+		cs_high = p->native_cs_high;
+	} else {
+		ss = spi->chip_select;
+		cs_high = !!(spi->mode & SPI_CS_HIGH);
+	}
+	sh_msiof_spi_set_pin_regs(p, ss, !!(spi->mode & SPI_CPOL),
 				  !!(spi->mode & SPI_CPHA),
 				  !!(spi->mode & SPI_3WIRE),
-				  !!(spi->mode & SPI_LSB_FIRST),
-				  !!(spi->mode & SPI_CS_HIGH));
+				  !!(spi->mode & SPI_LSB_FIRST), cs_high);
 	return 0;
 }
 
@@ -784,11 +813,21 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
 		goto stop_dma;
 	}
 
-	/* wait for tx fifo to be emptied / rx fifo to be filled */
+	/* wait for tx/rx DMA completion */
 	ret = sh_msiof_wait_for_completion(p);
 	if (ret)
 		goto stop_reset;
 
+	if (!rx) {
+		reinit_completion(&p->done);
+		sh_msiof_write(p, IER, IER_TEOFE);
+
+		/* wait for tx fifo to be emptied */
+		ret = sh_msiof_wait_for_completion(p);
+		if (ret)
+			goto stop_reset;
+	}
+
 	/* clear status bits */
 	sh_msiof_reset_str(p);
 
@@ -912,9 +951,8 @@ static int sh_msiof_transfer_one(struct spi_master *master,
 
 		ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
 		if (ret == -EAGAIN) {
-			pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
-				     dev_driver_string(&p->pdev->dev),
-				     dev_name(&p->pdev->dev));
+			dev_warn_once(&p->pdev->dev,
+				"DMA not available, falling back to PIO\n");
 			break;
 		}
 		if (ret)
@@ -1071,6 +1109,45 @@ static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
 }
 #endif
 
+static int sh_msiof_get_cs_gpios(struct sh_msiof_spi_priv *p)
+{
+	struct device *dev = &p->pdev->dev;
+	unsigned int used_ss_mask = 0;
+	unsigned int cs_gpios = 0;
+	unsigned int num_cs, i;
+	int ret;
+
+	ret = gpiod_count(dev, "cs");
+	if (ret <= 0)
+		return 0;
+
+	num_cs = max_t(unsigned int, ret, p->master->num_chipselect);
+	for (i = 0; i < num_cs; i++) {
+		struct gpio_desc *gpiod;
+
+		gpiod = devm_gpiod_get_index(dev, "cs", i, GPIOD_ASIS);
+		if (!IS_ERR(gpiod)) {
+			cs_gpios++;
+			continue;
+		}
+
+		if (PTR_ERR(gpiod) != -ENOENT)
+			return PTR_ERR(gpiod);
+
+		if (i >= MAX_SS) {
+			dev_err(dev, "Invalid native chip select %d\n", i);
+			return -EINVAL;
+		}
+		used_ss_mask |= BIT(i);
+	}
+	p->unused_ss = ffz(used_ss_mask);
+	if (cs_gpios && p->unused_ss >= MAX_SS) {
+		dev_err(dev, "No unused native chip select available\n");
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
 	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
 {
@@ -1284,13 +1361,18 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
 	if (p->info->rx_fifo_override)
 		p->rx_fifo_size = p->info->rx_fifo_override;
 
+	/* Setup GPIO chip selects */
+	master->num_chipselect = p->info->num_chipselect;
+	ret = sh_msiof_get_cs_gpios(p);
+	if (ret)
+		goto err1;
+
 	/* init master code */
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
 	master->flags = chipdata->master_flags;
 	master->bus_num = pdev->id;
 	master->dev.of_node = pdev->dev.of_node;
-	master->num_chipselect = p->info->num_chipselect;
 	master->setup = sh_msiof_spi_setup;
 	master->prepare_message = sh_msiof_prepare_message;
 	master->slave_abort = sh_msiof_slave_abort;