1 files changed, 132 insertions, 160 deletions

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 06324f17a0cb..a5d319e4aae6 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -63,6 +63,9 @@ struct dw8250_data {
 	struct clk		*pclk;
 	struct reset_control	*rst;
 	struct uart_8250_dma	dma;
+
+	unsigned int		skip_autocfg:1;
+	unsigned int		uart_16550_compatible:1;
 };
 
 #define BYT_PRV_CLK			0x800
@@ -224,10 +227,6 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
 	if (IS_ERR(d->clk) || !old)
 		goto out;
 
-	/* Not requesting clock rates below 1.8432Mhz */
-	if (baud < 115200)
-		baud = 115200;
-
 	clk_disable_unprepare(d->clk);
 	rate = clk_round_rate(d->clk, baud * 16);
 	ret = clk_set_rate(d->clk, rate);
@@ -244,24 +243,77 @@ out:
 	serial8250_do_set_termios(p, termios, old);
 }
 
-static bool dw8250_dma_filter(struct dma_chan *chan, void *param)
+/*
+ * dw8250_fallback_dma_filter will prevent the UART from getting just any free
+ * channel on platforms that have DMA engines, but don't have any channels
+ * assigned to the UART.
+ *
+ * REVISIT: This is a work around for limitation in the DMA Engine API. Once the
+ * core problem is fixed, this function is no longer needed.
+ */
+static bool dw8250_fallback_dma_filter(struct dma_chan *chan, void *param)
 {
 	return false;
 }
 
-static void dw8250_setup_port(struct uart_8250_port *up)
+static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
+{
+	return param == chan->device->dev->parent;
+}
+
+static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 {
-	struct uart_port	*p = &up->port;
-	u32			reg = readl(p->membase + DW_UART_UCV);
+	if (p->dev->of_node) {
+		struct device_node *np = p->dev->of_node;
+		int id;
+
+		/* get index of serial line, if found in DT aliases */
+		id = of_alias_get_id(np, "serial");
+		if (id >= 0)
+			p->line = id;
+#ifdef CONFIG_64BIT
+		if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
+			p->serial_in = dw8250_serial_inq;
+			p->serial_out = dw8250_serial_outq;
+			p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
+			p->type = PORT_OCTEON;
+			data->usr_reg = 0x27;
+			data->skip_autocfg = true;
+		}
+#endif
+	} else if (has_acpi_companion(p->dev)) {
+		p->iotype = UPIO_MEM32;
+		p->regshift = 2;
+		p->serial_in = dw8250_serial_in32;
+		p->set_termios = dw8250_set_termios;
+		/* So far none of there implement the Busy Functionality */
+		data->uart_16550_compatible = true;
+	}
+
+	/* Platforms with iDMA */
+	if (platform_get_resource_byname(to_platform_device(p->dev),
+					 IORESOURCE_MEM, "lpss_priv")) {
+		p->set_termios = dw8250_set_termios;
+		data->dma.rx_param = p->dev->parent;
+		data->dma.tx_param = p->dev->parent;
+		data->dma.fn = dw8250_idma_filter;
+	}
+}
+
+static void dw8250_setup_port(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+	u32 reg;
 
 	/*
 	 * If the Component Version Register returns zero, we know that
 	 * ADDITIONAL_FEATURES are not enabled. No need to go any further.
 	 */
+	reg = readl(p->membase + DW_UART_UCV);
 	if (!reg)
 		return;
 
-	dev_dbg_ratelimited(p->dev, "Designware UART version %c.%c%c\n",
+	dev_dbg(p->dev, "Designware UART version %c.%c%c\n",
 		(reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff);
 
 	reg = readl(p->membase + DW_UART_CPR);
@@ -273,7 +325,6 @@ static void dw8250_setup_port(struct uart_8250_port *up)
 		p->type = PORT_16550A;
 		p->flags |= UPF_FIXED_TYPE;
 		p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
-		up->tx_loadsz = p->fifosize;
 		up->capabilities = UART_CAP_FIFO;
 	}
 
@@ -281,166 +332,91 @@ static void dw8250_setup_port(struct uart_8250_port *up)
 		up->capabilities |= UART_CAP_AFE;
 }
 
-static int dw8250_probe_of(struct uart_port *p,
-			   struct dw8250_data *data)
+static int dw8250_probe(struct platform_device *pdev)
 {
-	struct device_node	*np = p->dev->of_node;
-	struct uart_8250_port *up = up_to_u8250p(p);
-	u32			val;
-	bool has_ucv = true;
-	int id;
+	struct uart_8250_port uart = {};
+	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	int irq = platform_get_irq(pdev, 0);
+	struct uart_port *p = &uart.port;
+	struct dw8250_data *data;
+	int err;
+	u32 val;
 
-#ifdef CONFIG_64BIT
-	if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
-		p->serial_in = dw8250_serial_inq;
-		p->serial_out = dw8250_serial_outq;
-		p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
-		p->type = PORT_OCTEON;
-		data->usr_reg = 0x27;
-		has_ucv = false;
-	} else
-#endif
-	if (!of_property_read_u32(np, "reg-io-width", &val)) {
-		switch (val) {
-		case 1:
-			break;
-		case 4:
-			p->iotype = UPIO_MEM32;
-			p->serial_in = dw8250_serial_in32;
-			p->serial_out = dw8250_serial_out32;
-			break;
-		default:
-			dev_err(p->dev, "unsupported reg-io-width (%u)\n", val);
-			return -EINVAL;
-		}
+	if (!regs) {
+		dev_err(&pdev->dev, "no registers defined\n");
+		return -EINVAL;
 	}
-	if (has_ucv)
-		dw8250_setup_port(up);
-
-	/* if we have a valid fifosize, try hooking up DMA here */
-	if (p->fifosize) {
-		up->dma = &data->dma;
 
-		up->dma->rxconf.src_maxburst = p->fifosize / 4;
-		up->dma->txconf.dst_maxburst = p->fifosize / 4;
+	if (irq < 0) {
+		if (irq != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "cannot get irq\n");
+		return irq;
 	}
 
-	if (!of_property_read_u32(np, "reg-shift", &val))
+	spin_lock_init(&p->lock);
+	p->mapbase	= regs->start;
+	p->irq		= irq;
+	p->handle_irq	= dw8250_handle_irq;
+	p->pm		= dw8250_do_pm;
+	p->type		= PORT_8250;
+	p->flags	= UPF_SHARE_IRQ | UPF_FIXED_PORT;
+	p->dev		= &pdev->dev;
+	p->iotype	= UPIO_MEM;
+	p->serial_in	= dw8250_serial_in;
+	p->serial_out	= dw8250_serial_out;
+
+	p->membase = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
+	if (!p->membase)
+		return -ENOMEM;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->dma.fn = dw8250_fallback_dma_filter;
+	data->usr_reg = DW_UART_USR;
+	p->private_data = data;
+
+	data->uart_16550_compatible = device_property_read_bool(p->dev,
+						"snps,uart-16550-compatible");
+
+	err = device_property_read_u32(p->dev, "reg-shift", &val);
+	if (!err)
 		p->regshift = val;
 
-	/* get index of serial line, if found in DT aliases */
-	id = of_alias_get_id(np, "serial");
-	if (id >= 0)
-		p->line = id;
+	err = device_property_read_u32(p->dev, "reg-io-width", &val);
+	if (!err && val == 4) {
+		p->iotype = UPIO_MEM32;
+		p->serial_in = dw8250_serial_in32;
+		p->serial_out = dw8250_serial_out32;
+	}
 
-	if (of_property_read_bool(np, "dcd-override")) {
+	if (device_property_read_bool(p->dev, "dcd-override")) {
 		/* Always report DCD as active */
 		data->msr_mask_on |= UART_MSR_DCD;
 		data->msr_mask_off |= UART_MSR_DDCD;
 	}
 
-	if (of_property_read_bool(np, "dsr-override")) {
+	if (device_property_read_bool(p->dev, "dsr-override")) {
 		/* Always report DSR as active */
 		data->msr_mask_on |= UART_MSR_DSR;
 		data->msr_mask_off |= UART_MSR_DDSR;
 	}
 
-	if (of_property_read_bool(np, "cts-override")) {
+	if (device_property_read_bool(p->dev, "cts-override")) {
 		/* Always report CTS as active */
 		data->msr_mask_on |= UART_MSR_CTS;
 		data->msr_mask_off |= UART_MSR_DCTS;
 	}
 
-	if (of_property_read_bool(np, "ri-override")) {
+	if (device_property_read_bool(p->dev, "ri-override")) {
 		/* Always report Ring indicator as inactive */
 		data->msr_mask_off |= UART_MSR_RI;
 		data->msr_mask_off |= UART_MSR_TERI;
 	}
 
-	return 0;
-}
-
-static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
-{
-	struct device *dev = param;
-
-	if (dev != chan->device->dev->parent)
-		return false;
-
-	return true;
-}
-
-static int dw8250_probe_acpi(struct uart_8250_port *up,
-			     struct dw8250_data *data)
-{
-	struct uart_port *p = &up->port;
-
-	dw8250_setup_port(up);
-
-	p->iotype = UPIO_MEM32;
-	p->serial_in = dw8250_serial_in32;
-	p->serial_out = dw8250_serial_out32;
-	p->regshift = 2;
-
-	/* Platforms with iDMA */
-	if (platform_get_resource_byname(to_platform_device(up->port.dev),
-					 IORESOURCE_MEM, "lpss_priv")) {
-		data->dma.rx_param = up->port.dev->parent;
-		data->dma.tx_param = up->port.dev->parent;
-		data->dma.fn = dw8250_idma_filter;
-	}
-
-	up->dma = &data->dma;
-	up->dma->rxconf.src_maxburst = p->fifosize / 4;
-	up->dma->txconf.dst_maxburst = p->fifosize / 4;
-
-	up->port.set_termios = dw8250_set_termios;
-
-	return 0;
-}
-
-static int dw8250_probe(struct platform_device *pdev)
-{
-	struct uart_8250_port uart = {};
-	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	int irq = platform_get_irq(pdev, 0);
-	struct dw8250_data *data;
-	int err;
-
-	if (!regs) {
-		dev_err(&pdev->dev, "no registers defined\n");
-		return -EINVAL;
-	}
-
-	if (irq < 0) {
-		if (irq != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "cannot get irq\n");
-		return irq;
-	}
-
-	spin_lock_init(&uart.port.lock);
-	uart.port.mapbase = regs->start;
-	uart.port.irq = irq;
-	uart.port.handle_irq = dw8250_handle_irq;
-	uart.port.pm = dw8250_do_pm;
-	uart.port.type = PORT_8250;
-	uart.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
-	uart.port.dev = &pdev->dev;
-
-	uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
-					 resource_size(regs));
-	if (!uart.port.membase)
-		return -ENOMEM;
-
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	data->usr_reg = DW_UART_USR;
-
 	/* Always ask for fixed clock rate from a property. */
-	device_property_read_u32(&pdev->dev, "clock-frequency",
-				 &uart.port.uartclk);
+	device_property_read_u32(p->dev, "clock-frequency", &p->uartclk);
 
 	/* If there is separate baudclk, get the rate from it. */
 	data->clk = devm_clk_get(&pdev->dev, "baudclk");
@@ -454,11 +430,11 @@ static int dw8250_probe(struct platform_device *pdev)
 			dev_warn(&pdev->dev, "could not enable optional baudclk: %d\n",
 				 err);
 		else
-			uart.port.uartclk = clk_get_rate(data->clk);
+			p->uartclk = clk_get_rate(data->clk);
 	}
 
 	/* If no clock rate is defined, fail. */
-	if (!uart.port.uartclk) {
+	if (!p->uartclk) {
 		dev_err(&pdev->dev, "clock rate not defined\n");
 		return -EINVAL;
 	}
@@ -484,26 +460,22 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (!IS_ERR(data->rst))
 		reset_control_deassert(data->rst);
 
-	data->dma.rx_param = data;
-	data->dma.tx_param = data;
-	data->dma.fn = dw8250_dma_filter;
+	dw8250_quirks(p, data);
 
-	uart.port.iotype = UPIO_MEM;
-	uart.port.serial_in = dw8250_serial_in;
-	uart.port.serial_out = dw8250_serial_out;
-	uart.port.private_data = data;
+	/* If the Busy Functionality is not implemented, don't handle it */
+	if (data->uart_16550_compatible) {
+		p->serial_out = NULL;
+		p->handle_irq = NULL;
+	}
 
-	if (pdev->dev.of_node) {
-		err = dw8250_probe_of(&uart.port, data);
-		if (err)
-			goto err_reset;
-	} else if (ACPI_HANDLE(&pdev->dev)) {
-		err = dw8250_probe_acpi(&uart, data);
-		if (err)
-			goto err_reset;
-	} else {
-		err = -ENODEV;
-		goto err_reset;
+	if (!data->skip_autocfg)
+		dw8250_setup_port(p);
+
+	/* If we have a valid fifosize, try hooking up DMA */
+	if (p->fifosize) {
+		data->dma.rxconf.src_maxburst = p->fifosize / 4;
+		data->dma.txconf.dst_maxburst = p->fifosize / 4;
+		uart.dma = &data->dma;
 	}
 
 	data->line = serial8250_register_8250_port(&uart);