1 files changed, 120 insertions, 99 deletions

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index acf318e7330c..56f0ca361deb 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -222,37 +222,13 @@
 	  | SPI_BF(name, value))
 
 /* Register access macros */
-#ifdef CONFIG_AVR32
-#define spi_readl(port, reg) \
-	__raw_readl((port)->regs + SPI_##reg)
-#define spi_writel(port, reg, value) \
-	__raw_writel((value), (port)->regs + SPI_##reg)
-
-#define spi_readw(port, reg) \
-	__raw_readw((port)->regs + SPI_##reg)
-#define spi_writew(port, reg, value) \
-	__raw_writew((value), (port)->regs + SPI_##reg)
-
-#define spi_readb(port, reg) \
-	__raw_readb((port)->regs + SPI_##reg)
-#define spi_writeb(port, reg, value) \
-	__raw_writeb((value), (port)->regs + SPI_##reg)
-#else
 #define spi_readl(port, reg) \
 	readl_relaxed((port)->regs + SPI_##reg)
 #define spi_writel(port, reg, value) \
 	writel_relaxed((value), (port)->regs + SPI_##reg)
-
-#define spi_readw(port, reg) \
-	readw_relaxed((port)->regs + SPI_##reg)
 #define spi_writew(port, reg, value) \
 	writew_relaxed((value), (port)->regs + SPI_##reg)
 
-#define spi_readb(port, reg) \
-	readb_relaxed((port)->regs + SPI_##reg)
-#define spi_writeb(port, reg, value) \
-	writeb_relaxed((value), (port)->regs + SPI_##reg)
-#endif
 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
  * cache operations; better heuristics consider wordsize and bitrate.
  */
@@ -299,17 +275,16 @@ struct atmel_spi {
 
 	bool			use_dma;
 	bool			use_pdc;
-	bool			use_cs_gpios;
 
 	bool			keep_cs;
-	bool			cs_active;
 
 	u32			fifo_size;
+	u8			native_cs_free;
+	u8			native_cs_for_gpio;
 };
 
 /* Controller-specific per-slave state */
 struct atmel_spi_device {
-	struct gpio_desc	*npcs_pin;
 	u32			csr;
 };
 
@@ -336,11 +311,9 @@ static bool atmel_spi_is_v2(struct atmel_spi *as)
  * transmitted")  Not so!  Workaround uses nCSx pins as GPIOs; or newer
  * controllers have CSAAT and friends.
  *
- * Since the CSAAT functionality is a bit weird on newer controllers as
- * well, we use GPIO to control nCSx pins on all controllers, updating
- * MR.PCS to avoid confusing the controller.  Using GPIOs also lets us
- * support active-high chipselects despite the controller's belief that
- * only active-low devices/systems exists.
+ * Even controller newer than ar91rm9200, using GPIOs can make sens as
+ * it lets us support active-high chipselects despite the controller's
+ * belief that only active-low devices/systems exists.
  *
  * However, at91rm9200 has a second erratum whereby nCS0 doesn't work
  * right when driven with GPIO.  ("Mode Fault does not allow more than one
@@ -352,30 +325,36 @@ static bool atmel_spi_is_v2(struct atmel_spi *as)
 static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 {
 	struct atmel_spi_device *asd = spi->controller_state;
+	int chip_select;
 	u32 mr;
 
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
+
 	if (atmel_spi_is_v2(as)) {
-		spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr);
+		spi_writel(as, CSR0 + 4 * chip_select, asd->csr);
 		/* For the low SPI version, there is a issue that PDC transfer
 		 * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS
 		 */
 		spi_writel(as, CSR0, asd->csr);
 		if (as->caps.has_wdrbt) {
 			spi_writel(as, MR,
-					SPI_BF(PCS, ~(0x01 << spi->chip_select))
+					SPI_BF(PCS, ~(0x01 << chip_select))
 					| SPI_BIT(WDRBT)
 					| SPI_BIT(MODFDIS)
 					| SPI_BIT(MSTR));
 		} else {
 			spi_writel(as, MR,
-					SPI_BF(PCS, ~(0x01 << spi->chip_select))
+					SPI_BF(PCS, ~(0x01 << chip_select))
 					| SPI_BIT(MODFDIS)
 					| SPI_BIT(MSTR));
 		}
 
 		mr = spi_readl(as, MR);
-		if (as->use_cs_gpios)
-			gpiod_set_value(asd->npcs_pin, 1);
+		if (spi->cs_gpiod)
+			gpiod_set_value(spi->cs_gpiod, 1);
 	} else {
 		u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
 		int i;
@@ -390,9 +369,9 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 		}
 
 		mr = spi_readl(as, MR);
-		mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
-		if (as->use_cs_gpios && spi->chip_select != 0)
-			gpiod_set_value(asd->npcs_pin, 1);
+		mr = SPI_BFINS(PCS, ~(1 << chip_select), mr);
+		if (spi->cs_gpiod)
+			gpiod_set_value(spi->cs_gpiod, 1);
 		spi_writel(as, MR, mr);
 	}
 
@@ -401,24 +380,29 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 
 static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
 {
-	struct atmel_spi_device *asd = spi->controller_state;
+	int chip_select;
 	u32 mr;
 
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
+
 	/* only deactivate *this* device; sometimes transfers to
 	 * another device may be active when this routine is called.
 	 */
 	mr = spi_readl(as, MR);
-	if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
+	if (~SPI_BFEXT(PCS, mr) & (1 << chip_select)) {
 		mr = SPI_BFINS(PCS, 0xf, mr);
 		spi_writel(as, MR, mr);
 	}
 
 	dev_dbg(&spi->dev, "DEactivate NPCS, mr %08x\n", mr);
 
-	if (!as->use_cs_gpios)
+	if (!spi->cs_gpiod)
 		spi_writel(as, CR, SPI_BIT(LASTXFER));
-	else if (atmel_spi_is_v2(as) || spi->chip_select != 0)
-		gpiod_set_value(asd->npcs_pin, 0);
+	else
+		gpiod_set_value(spi->cs_gpiod, 0);
 }
 
 static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock)
@@ -527,7 +511,7 @@ static int atmel_spi_configure_dma(struct spi_master *master,
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
+	master->dma_tx = dma_request_chan(dev, "tx");
 	if (IS_ERR(master->dma_tx)) {
 		err = PTR_ERR(master->dma_tx);
 		if (err == -EPROBE_DEFER) {
@@ -844,6 +828,12 @@ static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
 {
 	u32			scbr, csr;
 	unsigned long		bus_hz;
+	int chip_select;
+
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
 
 	/* v1 chips start out at half the peripheral bus speed. */
 	bus_hz = as->spi_clk;
@@ -872,9 +862,9 @@ static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
 			xfer->speed_hz, scbr, bus_hz);
 		return -EINVAL;
 	}
-	csr = spi_readl(as, CSR0 + 4 * spi->chip_select);
+	csr = spi_readl(as, CSR0 + 4 * chip_select);
 	csr = SPI_BFINS(SCBR, scbr, csr);
-	spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
+	spi_writel(as, CSR0 + 4 * chip_select, csr);
 
 	return 0;
 }
@@ -1173,40 +1163,105 @@ atmel_spi_pdc_interrupt(int irq, void *dev_id)
 	return ret;
 }
 
+static int atmel_word_delay_csr(struct spi_device *spi, struct atmel_spi *as)
+{
+	struct spi_delay *delay = &spi->word_delay;
+	u32 value = delay->value;
+
+	switch (delay->unit) {
+	case SPI_DELAY_UNIT_NSECS:
+		value /= 1000;
+		break;
+	case SPI_DELAY_UNIT_USECS:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return (as->spi_clk / 1000000 * value) >> 5;
+}
+
+static void initialize_native_cs_for_gpio(struct atmel_spi *as)
+{
+	int i;
+	struct spi_master *master = platform_get_drvdata(as->pdev);
+
+	if (!as->native_cs_free)
+		return; /* already initialized */
+
+	if (!master->cs_gpiods)
+		return; /* No CS GPIO */
+
+	/*
+	 * On the first version of the controller (AT91RM9200), CS0
+	 * can't be used associated with GPIO
+	 */
+	if (atmel_spi_is_v2(as))
+		i = 0;
+	else
+		i = 1;
+
+	for (; i < 4; i++)
+		if (master->cs_gpiods[i])
+			as->native_cs_free |= BIT(i);
+
+	if (as->native_cs_free)
+		as->native_cs_for_gpio = ffs(as->native_cs_free);
+}
+
 static int atmel_spi_setup(struct spi_device *spi)
 {
 	struct atmel_spi	*as;
 	struct atmel_spi_device	*asd;
 	u32			csr;
 	unsigned int		bits = spi->bits_per_word;
+	int chip_select;
+	int			word_delay_csr;
 
 	as = spi_master_get_devdata(spi->master);
 
 	/* see notes above re chipselect */
-	if (!atmel_spi_is_v2(as)
-			&& spi->chip_select == 0
-			&& (spi->mode & SPI_CS_HIGH)) {
-		dev_dbg(&spi->dev, "setup: can't be active-high\n");
+	if (!spi->cs_gpiod && (spi->mode & SPI_CS_HIGH)) {
+		dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
 		return -EINVAL;
 	}
 
+	/* Setup() is called during spi_register_controller(aka
+	 * spi_register_master) but after all membmers of the cs_gpiod
+	 * array have been filled, so we can looked for which native
+	 * CS will be free for using with GPIO
+	 */
+	initialize_native_cs_for_gpio(as);
+
+	if (spi->cs_gpiod && as->native_cs_free) {
+		dev_err(&spi->dev,
+			"No native CS available to support this GPIO CS\n");
+		return -EBUSY;
+	}
+
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
+
 	csr = SPI_BF(BITS, bits - 8);
 	if (spi->mode & SPI_CPOL)
 		csr |= SPI_BIT(CPOL);
 	if (!(spi->mode & SPI_CPHA))
 		csr |= SPI_BIT(NCPHA);
-	if (!as->use_cs_gpios)
-		csr |= SPI_BIT(CSAAT);
 
-	/* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
-	 */
+	if (!spi->cs_gpiod)
+		csr |= SPI_BIT(CSAAT);
 	csr |= SPI_BF(DLYBS, 0);
 
+	word_delay_csr = atmel_word_delay_csr(spi, as);
+	if (word_delay_csr < 0)
+		return word_delay_csr;
+
 	/* DLYBCT adds delays between words.  This is useful for slow devices
 	 * that need a bit of time to setup the next transfer.
 	 */
-	csr |= SPI_BF(DLYBCT,
-			(as->spi_clk / 1000000 * spi->word_delay_usecs) >> 5);
+	csr |= SPI_BF(DLYBCT, word_delay_csr);
 
 	asd = spi->controller_state;
 	if (!asd) {
@@ -1214,21 +1269,6 @@ static int atmel_spi_setup(struct spi_device *spi)
 		if (!asd)
 			return -ENOMEM;
 
-		/*
-		 * If use_cs_gpios is true this means that we have "cs-gpios"
-		 * defined in the device tree node so we should have
-		 * gotten the GPIO lines from the device tree inside the
-		 * SPI core. Warn if this is not the case but continue since
-		 * CS GPIOs are after all optional.
-		 */
-		if (as->use_cs_gpios) {
-			if (!spi->cs_gpiod) {
-				dev_err(&spi->dev,
-					"host claims to use CS GPIOs but no CS found in DT by the SPI core\n");
-			}
-			asd->npcs_pin = spi->cs_gpiod;
-		}
-
 		spi->controller_state = asd;
 	}
 
@@ -1239,7 +1279,7 @@ static int atmel_spi_setup(struct spi_device *spi)
 		bits, spi->mode, spi->chip_select, csr);
 
 	if (!atmel_spi_is_v2(as))
-		spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
+		spi_writel(as, CSR0 + 4 * chip_select, csr);
 
 	return 0;
 }
@@ -1368,19 +1408,16 @@ static int atmel_spi_one_transfer(struct spi_master *master,
 		&& as->use_pdc)
 		atmel_spi_dma_unmap_xfer(master, xfer);
 
-	if (xfer->delay_usecs)
-		udelay(xfer->delay_usecs);
+	spi_transfer_delay_exec(xfer);
 
 	if (xfer->cs_change) {
 		if (list_is_last(&xfer->transfer_list,
 				 &msg->transfers)) {
 			as->keep_cs = true;
 		} else {
-			as->cs_active = !as->cs_active;
-			if (as->cs_active)
-				cs_activate(as, msg->spi);
-			else
-				cs_deactivate(as, msg->spi);
+			cs_deactivate(as, msg->spi);
+			udelay(10);
+			cs_activate(as, msg->spi);
 		}
 	}
 
@@ -1403,7 +1440,6 @@ static int atmel_spi_transfer_one_message(struct spi_master *master,
 	atmel_spi_lock(as);
 	cs_activate(as, spi);
 
-	as->cs_active = true;
 	as->keep_cs = false;
 
 	msg->status = 0;
@@ -1527,7 +1563,7 @@ static int atmel_spi_probe(struct platform_device *pdev)
 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
 	master->dev.of_node = pdev->dev.of_node;
 	master->bus_num = pdev->id;
-	master->num_chipselect = master->dev.of_node ? 0 : 4;
+	master->num_chipselect = 4;
 	master->setup = atmel_spi_setup;
 	master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
 	master->transfer_one_message = atmel_spi_transfer_one_message;
@@ -1555,19 +1591,6 @@ static int atmel_spi_probe(struct platform_device *pdev)
 
 	atmel_get_caps(as);
 
-	/*
-	 * If there are chip selects in the device tree, those will be
-	 * discovered by the SPI core when registering the SPI master
-	 * and assigned to each SPI device.
-	 */
-	as->use_cs_gpios = true;
-	if (atmel_spi_is_v2(as) &&
-	    pdev->dev.of_node &&
-	    !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) {
-		as->use_cs_gpios = false;
-		master->num_chipselect = 4;
-	}
-
 	as->use_dma = false;
 	as->use_pdc = false;
 	if (as->caps.has_dma_support) {
@@ -1775,20 +1798,18 @@ static const struct dev_pm_ops atmel_spi_pm_ops = {
 #define ATMEL_SPI_PM_OPS	NULL
 #endif
 
-#if defined(CONFIG_OF)
 static const struct of_device_id atmel_spi_dt_ids[] = {
 	{ .compatible = "atmel,at91rm9200-spi" },
 	{ /* sentinel */ }
 };
 
 MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
-#endif
 
 static struct platform_driver atmel_spi_driver = {
 	.driver		= {
 		.name	= "atmel_spi",
 		.pm	= ATMEL_SPI_PM_OPS,
-		.of_match_table	= of_match_ptr(atmel_spi_dt_ids),
+		.of_match_table	= atmel_spi_dt_ids,
 	},
 	.probe		= atmel_spi_probe,
 	.remove		= atmel_spi_remove,