1 files changed, 152 insertions, 51 deletions

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 54fdc7866ea1..fe3d41cc8416 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -216,6 +216,8 @@ struct imx_port {
 	unsigned int		tx_bytes;
 	unsigned int		dma_tx_nents;
 	wait_queue_head_t	dma_wait;
+	unsigned int            saved_reg[10];
+	bool			context_saved;
 };
 
 struct imx_port_ucrs {
@@ -700,7 +702,8 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
 		if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
 			goto out;
 
-		tty_insert_flip_char(port, rx, flg);
+		if (tty_insert_flip_char(port, rx, flg) == 0)
+			sport->port.icount.buf_overrun++;
 	}
 
 out:
@@ -766,7 +769,6 @@ static irqreturn_t imx_int(int irq, void *dev_id)
 		writel(USR1_AWAKE, sport->port.membase + USR1);
 
 	if (sts2 & USR2_ORE) {
-		dev_err(sport->port.dev, "Rx FIFO overrun\n");
 		sport->port.icount.overrun++;
 		writel(USR2_ORE, sport->port.membase + USR2);
 	}
@@ -921,8 +923,13 @@ static void dma_rx_callback(void *data)
 	dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
 
 	if (count) {
-		if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ))
-			tty_insert_flip_string(port, sport->rx_buf, count);
+		if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
+			int bytes = tty_insert_flip_string(port, sport->rx_buf,
+					count);
+
+			if (bytes != count)
+				sport->port.icount.buf_overrun++;
+		}
 		tty_flip_buffer_push(port);
 
 		start_rx_dma(sport);
@@ -1624,12 +1631,12 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
 	int locked = 1;
 	int retval;
 
-	retval = clk_enable(sport->clk_per);
+	retval = clk_prepare_enable(sport->clk_per);
 	if (retval)
 		return;
-	retval = clk_enable(sport->clk_ipg);
+	retval = clk_prepare_enable(sport->clk_ipg);
 	if (retval) {
-		clk_disable(sport->clk_per);
+		clk_disable_unprepare(sport->clk_per);
 		return;
 	}
 
@@ -1668,8 +1675,8 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
 	if (locked)
 		spin_unlock_irqrestore(&sport->port.lock, flags);
 
-	clk_disable(sport->clk_ipg);
-	clk_disable(sport->clk_per);
+	clk_disable_unprepare(sport->clk_ipg);
+	clk_disable_unprepare(sport->clk_per);
 }
 
 /*
@@ -1770,15 +1777,7 @@ imx_console_setup(struct console *co, char *options)
 
 	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
 
-	clk_disable(sport->clk_ipg);
-	if (retval) {
-		clk_unprepare(sport->clk_ipg);
-		goto error_console;
-	}
-
-	retval = clk_prepare(sport->clk_per);
-	if (retval)
-		clk_disable_unprepare(sport->clk_ipg);
+	clk_disable_unprepare(sport->clk_ipg);
 
 error_console:
 	return retval;
@@ -1810,36 +1809,6 @@ static struct uart_driver imx_reg = {
 	.cons           = IMX_CONSOLE,
 };
 
-static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
-{
-	struct imx_port *sport = platform_get_drvdata(dev);
-	unsigned int val;
-
-	/* enable wakeup from i.MX UART */
-	val = readl(sport->port.membase + UCR3);
-	val |= UCR3_AWAKEN;
-	writel(val, sport->port.membase + UCR3);
-
-	uart_suspend_port(&imx_reg, &sport->port);
-
-	return 0;
-}
-
-static int serial_imx_resume(struct platform_device *dev)
-{
-	struct imx_port *sport = platform_get_drvdata(dev);
-	unsigned int val;
-
-	/* disable wakeup from i.MX UART */
-	val = readl(sport->port.membase + UCR3);
-	val &= ~UCR3_AWAKEN;
-	writel(val, sport->port.membase + UCR3);
-
-	uart_resume_port(&imx_reg, &sport->port);
-
-	return 0;
-}
-
 #ifdef CONFIG_OF
 /*
  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
@@ -1901,7 +1870,7 @@ static int serial_imx_probe(struct platform_device *pdev)
 {
 	struct imx_port *sport;
 	void __iomem *base;
-	int ret = 0;
+	int ret = 0, reg;
 	struct resource *res;
 	int txirq, rxirq, rtsirq;
 
@@ -1956,6 +1925,19 @@ static int serial_imx_probe(struct platform_device *pdev)
 
 	sport->port.uartclk = clk_get_rate(sport->clk_per);
 
+	/* For register access, we only need to enable the ipg clock. */
+	ret = clk_prepare_enable(sport->clk_ipg);
+	if (ret)
+		return ret;
+
+	/* Disable interrupts before requesting them */
+	reg = readl_relaxed(sport->port.membase + UCR1);
+	reg &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
+		 UCR1_TXMPTYEN | UCR1_RTSDEN);
+	writel_relaxed(reg, sport->port.membase + UCR1);
+
+	clk_disable_unprepare(sport->clk_ipg);
+
 	/*
 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
 	 * chips only have one interrupt.
@@ -1991,16 +1973,135 @@ static int serial_imx_remove(struct platform_device *pdev)
 	return uart_remove_one_port(&imx_reg, &sport->port);
 }
 
+static void serial_imx_restore_context(struct imx_port *sport)
+{
+	if (!sport->context_saved)
+		return;
+
+	writel(sport->saved_reg[4], sport->port.membase + UFCR);
+	writel(sport->saved_reg[5], sport->port.membase + UESC);
+	writel(sport->saved_reg[6], sport->port.membase + UTIM);
+	writel(sport->saved_reg[7], sport->port.membase + UBIR);
+	writel(sport->saved_reg[8], sport->port.membase + UBMR);
+	writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS);
+	writel(sport->saved_reg[0], sport->port.membase + UCR1);
+	writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2);
+	writel(sport->saved_reg[2], sport->port.membase + UCR3);
+	writel(sport->saved_reg[3], sport->port.membase + UCR4);
+	sport->context_saved = false;
+}
+
+static void serial_imx_save_context(struct imx_port *sport)
+{
+	/* Save necessary regs */
+	sport->saved_reg[0] = readl(sport->port.membase + UCR1);
+	sport->saved_reg[1] = readl(sport->port.membase + UCR2);
+	sport->saved_reg[2] = readl(sport->port.membase + UCR3);
+	sport->saved_reg[3] = readl(sport->port.membase + UCR4);
+	sport->saved_reg[4] = readl(sport->port.membase + UFCR);
+	sport->saved_reg[5] = readl(sport->port.membase + UESC);
+	sport->saved_reg[6] = readl(sport->port.membase + UTIM);
+	sport->saved_reg[7] = readl(sport->port.membase + UBIR);
+	sport->saved_reg[8] = readl(sport->port.membase + UBMR);
+	sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS);
+	sport->context_saved = true;
+}
+
+static void serial_imx_enable_wakeup(struct imx_port *sport, bool on)
+{
+	unsigned int val;
+
+	val = readl(sport->port.membase + UCR3);
+	if (on)
+		val |= UCR3_AWAKEN;
+	else
+		val &= ~UCR3_AWAKEN;
+	writel(val, sport->port.membase + UCR3);
+
+	val = readl(sport->port.membase + UCR1);
+	if (on)
+		val |= UCR1_RTSDEN;
+	else
+		val &= ~UCR1_RTSDEN;
+	writel(val, sport->port.membase + UCR1);
+}
+
+static int imx_serial_port_suspend_noirq(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct imx_port *sport = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = clk_enable(sport->clk_ipg);
+	if (ret)
+		return ret;
+
+	serial_imx_save_context(sport);
+
+	clk_disable(sport->clk_ipg);
+
+	return 0;
+}
+
+static int imx_serial_port_resume_noirq(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct imx_port *sport = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = clk_enable(sport->clk_ipg);
+	if (ret)
+		return ret;
+
+	serial_imx_restore_context(sport);
+
+	clk_disable(sport->clk_ipg);
+
+	return 0;
+}
+
+static int imx_serial_port_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct imx_port *sport = platform_get_drvdata(pdev);
+
+	/* enable wakeup from i.MX UART */
+	serial_imx_enable_wakeup(sport, true);
+
+	uart_suspend_port(&imx_reg, &sport->port);
+
+	return 0;
+}
+
+static int imx_serial_port_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct imx_port *sport = platform_get_drvdata(pdev);
+
+	/* disable wakeup from i.MX UART */
+	serial_imx_enable_wakeup(sport, false);
+
+	uart_resume_port(&imx_reg, &sport->port);
+
+	return 0;
+}
+
+static const struct dev_pm_ops imx_serial_port_pm_ops = {
+	.suspend_noirq = imx_serial_port_suspend_noirq,
+	.resume_noirq = imx_serial_port_resume_noirq,
+	.suspend = imx_serial_port_suspend,
+	.resume = imx_serial_port_resume,
+};
+
 static struct platform_driver serial_imx_driver = {
 	.probe		= serial_imx_probe,
 	.remove		= serial_imx_remove,
 
-	.suspend	= serial_imx_suspend,
-	.resume		= serial_imx_resume,
 	.id_table	= imx_uart_devtype,
 	.driver		= {
 		.name	= "imx-uart",
 		.of_match_table = imx_uart_dt_ids,
+		.pm	= &imx_serial_port_pm_ops,
 	},
 };