1 files changed, 53 insertions, 66 deletions

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index fb65dc601b23..5875a7b9b4b1 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -37,6 +37,7 @@
 #define MTK_UART_IER_RTSI	0x40	/* Enable RTS Modem status interrupt */
 #define MTK_UART_IER_CTSI	0x80	/* Enable CTS Modem status interrupt */
 
+#define MTK_UART_EFR		38	/* I/O: Extended Features Register */
 #define MTK_UART_EFR_EN		0x10	/* Enable enhancement feature */
 #define MTK_UART_EFR_RTS	0x40	/* Enable hardware rx flow control */
 #define MTK_UART_EFR_CTS	0x80	/* Enable hardware tx flow control */
@@ -53,6 +54,9 @@
 #define MTK_UART_TX_TRIGGER	1
 #define MTK_UART_RX_TRIGGER	MTK_UART_RX_SIZE
 
+#define MTK_UART_XON1		40	/* I/O: Xon character 1 */
+#define MTK_UART_XOFF1		42	/* I/O: Xoff character 1 */
+
 #ifdef CONFIG_SERIAL_8250_DMA
 enum dma_rx_status {
 	DMA_RX_START = 0,
@@ -98,7 +102,7 @@ static void mtk8250_dma_rx_complete(void *param)
 	if (data->rx_status == DMA_RX_SHUTDOWN)
 		return;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
 	total = dma->rx_size - state.residue;
@@ -124,7 +128,7 @@ static void mtk8250_dma_rx_complete(void *param)
 
 	mtk8250_rx_dma(up);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static void mtk8250_rx_dma(struct uart_8250_port *up)
@@ -169,7 +173,7 @@ static void mtk8250_dma_enable(struct uart_8250_port *up)
 		   MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_EFR, UART_EFR_ECB);
+	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
 	serial_out(up, UART_LCR, lcr);
 
 	if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
@@ -195,7 +199,7 @@ static int mtk8250_startup(struct uart_port *port)
 
 	if (up->dma) {
 		data->rx_status = DMA_RX_START;
-		uart_circ_clear(&port->state->xmit);
+		kfifo_reset(&port->state->port.xmit_fifo);
 	}
 #endif
 	memset(&port->icount, 0, sizeof(port->icount));
@@ -205,24 +209,34 @@ static int mtk8250_startup(struct uart_port *port)
 
 static void mtk8250_shutdown(struct uart_port *port)
 {
-#ifdef CONFIG_SERIAL_8250_DMA
 	struct uart_8250_port *up = up_to_u8250p(port);
 	struct mtk8250_data *data = port->private_data;
+	int irq = data->rx_wakeup_irq;
 
+#ifdef CONFIG_SERIAL_8250_DMA
 	if (up->dma)
 		data->rx_status = DMA_RX_SHUTDOWN;
 #endif
 
-	return serial8250_do_shutdown(port);
+	serial8250_do_shutdown(port);
+
+	if (irq >= 0)
+		serial8250_do_set_mctrl(&up->port, TIOCM_RTS);
 }
 
 static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
 {
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
 	serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
 }
 
 static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
 {
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
 	serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
 }
 
@@ -231,8 +245,11 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
 	struct uart_port *port = &up->port;
 	int lcr = serial_in(up, UART_LCR);
 
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&port->lock);
+
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_EFR, UART_EFR_ECB);
+	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
 	serial_out(up, UART_LCR, lcr);
 	lcr = serial_in(up, UART_LCR);
 
@@ -241,7 +258,7 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
 		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
 		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_out(up, UART_EFR, serial_in(up, UART_EFR) &
+		serial_out(up, MTK_UART_EFR, serial_in(up, MTK_UART_EFR) &
 			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)));
 		serial_out(up, UART_LCR, lcr);
 		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI |
@@ -255,8 +272,8 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 
 		/*enable hw flow control*/
-		serial_out(up, UART_EFR, MTK_UART_EFR_HW_FC |
-			(serial_in(up, UART_EFR) &
+		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_HW_FC |
+			(serial_in(up, MTK_UART_EFR) &
 			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
 
 		serial_out(up, UART_LCR, lcr);
@@ -270,12 +287,12 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 
 		/*enable sw flow control */
-		serial_out(up, UART_EFR, MTK_UART_EFR_XON1_XOFF1 |
-			(serial_in(up, UART_EFR) &
+		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_XON1_XOFF1 |
+			(serial_in(up, MTK_UART_EFR) &
 			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
 
-		serial_out(up, UART_XON1, START_CHAR(port->state->port.tty));
-		serial_out(up, UART_XOFF1, STOP_CHAR(port->state->port.tty));
+		serial_out(up, MTK_UART_XON1, START_CHAR(port->state->port.tty));
+		serial_out(up, MTK_UART_XOFF1, STOP_CHAR(port->state->port.tty));
 		serial_out(up, UART_LCR, lcr);
 		mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI);
 		mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI);
@@ -287,12 +304,12 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
 
 static void
 mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
-			struct ktermios *old)
+		    const struct ktermios *old)
 {
-	unsigned short fraction_L_mapping[] = {
+	static const unsigned short fraction_L_mapping[] = {
 		0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
 	};
-	unsigned short fraction_M_mapping[] = {
+	static const unsigned short fraction_M_mapping[] = {
 		0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
 	};
 	struct uart_8250_port *up = up_to_u8250p(port);
@@ -329,8 +346,8 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 	/*
 	 * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
 	 *
-	 * We need to recalcualte the quot register, as the claculation depends
-	 * on the vaule in the highspeed register.
+	 * We need to recalculate the quot register, as the calculation depends
+	 * on the value in the highspeed register.
 	 *
 	 * Some baudrates are not supported by the chip, so we use the next
 	 * lower rate supported and update termios c_flag.
@@ -355,7 +372,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 	 * Ok, we're now changing the port state.  Do it with
 	 * interrupts disabled.
 	 */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -403,7 +420,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (uart_console(port))
 		up->port.cons->cflag = termios->c_cflag;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	/* Don't rewrite B0 */
 	if (tty_termios_baud_rate(termios))
 		tty_termios_encode_baud_rate(termios, baud, baud);
@@ -418,12 +435,8 @@ static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
 	while
 		(serial_in(up, MTK_UART_DEBUG0));
 
-	if (data->clk_count == 0U) {
-		dev_dbg(dev, "%s clock count is 0\n", __func__);
-	} else {
-		clk_disable_unprepare(data->bus_clk);
-		data->clk_count--;
-	}
+	clk_disable_unprepare(data->uart_clk);
+	clk_disable_unprepare(data->bus_clk);
 
 	return 0;
 }
@@ -431,19 +444,9 @@ static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
 static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
 {
 	struct mtk8250_data *data = dev_get_drvdata(dev);
-	int err;
 
-	if (data->clk_count > 0U) {
-		dev_dbg(dev, "%s clock count is %d\n", __func__,
-			data->clk_count);
-	} else {
-		err = clk_prepare_enable(data->bus_clk);
-		if (err) {
-			dev_warn(dev, "Can't enable bus clock\n");
-			return err;
-		}
-		data->clk_count++;
-	}
+	clk_prepare_enable(data->bus_clk);
+	clk_prepare_enable(data->uart_clk);
 
 	return 0;
 }
@@ -452,14 +455,12 @@ static void
 mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 {
 	if (!state)
-		if (!mtk8250_runtime_resume(port->dev))
-			pm_runtime_get_sync(port->dev);
+		pm_runtime_get_sync(port->dev);
 
 	serial8250_do_pm(port, state, old);
 
 	if (state)
-		if (!pm_runtime_put_sync_suspend(port->dev))
-			mtk8250_runtime_suspend(port->dev);
+		pm_runtime_put_sync_suspend(port->dev);
 }
 
 #ifdef CONFIG_SERIAL_8250_DMA
@@ -476,13 +477,13 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 	int dmacnt;
 #endif
 
-	data->uart_clk = devm_clk_get(&pdev->dev, "baud");
+	data->uart_clk = devm_clk_get_enabled(&pdev->dev, "baud");
 	if (IS_ERR(data->uart_clk)) {
 		/*
 		 * For compatibility with older device trees try unnamed
 		 * clk when no baud clk can be found.
 		 */
-		data->uart_clk = devm_clk_get(&pdev->dev, NULL);
+		data->uart_clk = devm_clk_get_enabled(&pdev->dev, NULL);
 		if (IS_ERR(data->uart_clk)) {
 			dev_warn(&pdev->dev, "Can't get uart clock\n");
 			return PTR_ERR(data->uart_clk);
@@ -491,7 +492,7 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 		return 0;
 	}
 
-	data->bus_clk = devm_clk_get(&pdev->dev, "bus");
+	data->bus_clk = devm_clk_get_enabled(&pdev->dev, "bus");
 	if (IS_ERR(data->bus_clk))
 		return PTR_ERR(data->bus_clk);
 
@@ -574,28 +575,19 @@ static int mtk8250_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, data);
 
-	pm_runtime_enable(&pdev->dev);
-	err = mtk8250_runtime_resume(&pdev->dev);
-	if (err)
-		goto err_pm_disable;
-
 	data->line = serial8250_register_8250_port(&uart);
-	if (data->line < 0) {
-		err = data->line;
-		goto err_pm_disable;
-	}
+	if (data->line < 0)
+		return data->line;
 
 	data->rx_wakeup_irq = platform_get_irq_optional(pdev, 1);
 
-	return 0;
-
-err_pm_disable:
-	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
 
-	return err;
+	return 0;
 }
 
-static int mtk8250_remove(struct platform_device *pdev)
+static void mtk8250_remove(struct platform_device *pdev)
 {
 	struct mtk8250_data *data = platform_get_drvdata(pdev);
 
@@ -605,11 +597,6 @@ static int mtk8250_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
-
-	if (!pm_runtime_status_suspended(&pdev->dev))
-		mtk8250_runtime_suspend(&pdev->dev);
-
-	return 0;
 }
 
 static int __maybe_unused mtk8250_suspend(struct device *dev)