1 files changed, 48 insertions, 55 deletions

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index dfeff3951f93..a67a606c38eb 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Driver for Motorola/Freescale IMX serial ports
  *
@@ -5,16 +6,6 @@
  *
  * Author: Sascha Hauer <sascha@saschahauer.de>
  * Copyright (C) 2004 Pengutronix
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
@@ -334,7 +325,8 @@ static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2)
 {
         *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
 
-        mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
+        sport->port.mctrl |= TIOCM_RTS;
+        mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 }
 
 static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
@@ -342,7 +334,8 @@ static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
         *ucr2 &= ~UCR2_CTSC;
         *ucr2 |= UCR2_CTS;
 
-        mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
+        sport->port.mctrl &= ~TIOCM_RTS;
+        mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 }
 
 static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
@@ -714,8 +707,6 @@ static void imx_disable_rx_int(struct imx_port *sport)
 {
         unsigned long temp;
 
-        sport->dma_is_rxing = 1;
-
         /* disable the receiver ready and aging timer interrupts */
         temp = readl(sport->port.membase + UCR1);
         temp &= ~(UCR1_RRDYEN);
@@ -732,29 +723,6 @@ static void imx_disable_rx_int(struct imx_port *sport)
 }
 
 static void clear_rx_errors(struct imx_port *sport);
-static int start_rx_dma(struct imx_port *sport);
-/*
- * If the RXFIFO is filled with some data, and then we
- * arise a DMA operation to receive them.
- */
-static void imx_dma_rxint(struct imx_port *sport)
-{
-        unsigned long temp;
-        unsigned long flags;
-
-        spin_lock_irqsave(&sport->port.lock, flags);
-
-        temp = readl(sport->port.membase + USR2);
-        if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
-
-                imx_disable_rx_int(sport);
-
-                /* tell the DMA to receive the data. */
-                start_rx_dma(sport);
-        }
-
-        spin_unlock_irqrestore(&sport->port.lock, flags);
-}
 
 /*
  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
@@ -816,11 +784,8 @@ static irqreturn_t imx_int(int irq, void *dev_id)
         sts = readl(sport->port.membase + USR1);
         sts2 = readl(sport->port.membase + USR2);
 
-        if (sts & (USR1_RRDY | USR1_AGTIM)) {
-                if (sport->dma_is_enabled)
-                        imx_dma_rxint(sport);
-                else
-                        imx_rxint(irq, dev_id);
+        if (!sport->dma_is_enabled && (sts & (USR1_RRDY | USR1_AGTIM))) {
+                imx_rxint(irq, dev_id);
                 ret = IRQ_HANDLED;
         }
 
@@ -1074,6 +1039,7 @@ static int start_rx_dma(struct imx_port *sport)
         desc->callback_param = sport;
 
         dev_dbg(dev, "RX: prepare for the DMA.\n");
+        sport->dma_is_rxing = 1;
         sport->rx_cookie = dmaengine_submit(desc);
         dma_async_issue_pending(chan);
         return 0;
@@ -1165,7 +1131,7 @@ static int imx_uart_dma_init(struct imx_port *sport)
                 goto err;
         }
 
-        sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
+        sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
         if (!sport->rx_buf) {
                 ret = -ENOMEM;
                 goto err;
@@ -1207,10 +1173,6 @@ static void imx_enable_dma(struct imx_port *sport)
         temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN;
         writel(temp, sport->port.membase + UCR1);
 
-        temp = readl(sport->port.membase + UCR2);
-        temp |= UCR2_ATEN;
-        writel(temp, sport->port.membase + UCR2);
-
         imx_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
 
         sport->dma_is_enabled = 1;
@@ -1411,15 +1373,19 @@ static void imx_flush_buffer(struct uart_port *port)
                 temp = readl(sport->port.membase + UCR1);
                 temp &= ~UCR1_TDMAEN;
                 writel(temp, sport->port.membase + UCR1);
-                sport->dma_is_txing = false;
+                sport->dma_is_txing = 0;
         }
 
         /*
          * According to the Reference Manual description of the UART SRST bit:
+         *
          * "Reset the transmit and receive state machines,
          * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
-         * and UTS[6-3]". As we don't need to restore the old values from
-         * USR1, USR2, URXD, UTXD, only save/restore the other four registers
+         * and UTS[6-3]".
+         *
+         * We don't need to restore the old values from USR1, USR2, URXD and
+         * UTXD. UBRC is read only, so only save/restore the other three
+         * registers.
          */
         ubir = readl(sport->port.membase + UBIR);
         ubmr = readl(sport->port.membase + UBMR);
@@ -2051,6 +2017,8 @@ static int serial_imx_probe_dt(struct imx_port *sport,
         if (of_get_property(np, "rts-gpios", NULL))
                 sport->have_rtsgpio = 1;
 
+        of_get_rs485_mode(np, &sport->port.rs485);
+
         return 0;
 }
 #else
@@ -2112,12 +2080,9 @@ static int serial_imx_probe(struct platform_device *pdev)
         sport->port.fifosize = 32;
         sport->port.ops = &imx_pops;
         sport->port.rs485_config = imx_rs485_config;
-        sport->port.rs485.flags =
-                SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX;
+        sport->port.rs485.flags |= SER_RS485_RTS_ON_SEND;
         sport->port.flags = UPF_BOOT_AUTOCONF;
-        init_timer(&sport->timer);
-        sport->timer.function = imx_timeout;
-        sport->timer.data     = (unsigned long)sport;
+        setup_timer(&sport->timer, imx_timeout, (unsigned long)sport);
 
         sport->gpios = mctrl_gpio_init(&sport->port, 0);
         if (IS_ERR(sport->gpios))
@@ -2346,11 +2311,39 @@ static int imx_serial_port_resume(struct device *dev)
         return 0;
 }
 
+static int imx_serial_port_freeze(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct imx_port *sport = platform_get_drvdata(pdev);
+
+        uart_suspend_port(&imx_reg, &sport->port);
+
+        /* Needed to enable clock in suspend_noirq */
+        return clk_prepare(sport->clk_ipg);
+}
+
+static int imx_serial_port_thaw(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct imx_port *sport = platform_get_drvdata(pdev);
+
+        uart_resume_port(&imx_reg, &sport->port);
+
+        clk_unprepare(sport->clk_ipg);
+
+        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,
+        .freeze_noirq = imx_serial_port_suspend_noirq,
+        .restore_noirq = imx_serial_port_resume_noirq,
         .suspend = imx_serial_port_suspend,
         .resume = imx_serial_port_resume,
+        .freeze = imx_serial_port_freeze,
+        .thaw = imx_serial_port_thaw,
+        .restore = imx_serial_port_thaw,
 };
 
 static struct platform_driver serial_imx_driver = {