target/linux/layerscape/patches-4.9/816-tty-serial-support-layerscape.patch

   1 From 469daac0faff06209bc1d1390571b860d153a82b Mon Sep 17 00:00:00 2001
   2 From: Yangbo Lu <yangbo.lu@nxp.com>
   3 Date: Wed, 27 Sep 2017 10:33:47 +0800
   4 Subject: [PATCH] tty: serial: support layerscape
   5
   6 This is a integrated patch for layerscape uart support.
   7
   8 Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
   9 Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
  10 Signed-off-by: Stefan Agner <stefan@agner.ch>
  11 Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
  12 ---
  13  drivers/tty/serial/fsl_lpuart.c | 66 ++++++++++++++++++++++++++++-------------
  14  1 file changed, 46 insertions(+), 20 deletions(-)
  15
  16 diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
  17 index 76103f2c..61453820 100644
  18 --- a/drivers/tty/serial/fsl_lpuart.c
  19 +++ b/drivers/tty/serial/fsl_lpuart.c
  20 @@ -231,6 +231,8 @@
  21  #define DEV_NAME       "ttyLP"
  22  #define UART_NR                6
  23
  24 +static DECLARE_BITMAP(linemap, UART_NR);
  25 +
  26  struct lpuart_port {
  27         struct uart_port        port;
  28         struct clk              *clk;
  29 @@ -1348,6 +1350,18 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
  30         /* ask the core to calculate the divisor */
  31         baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
  32
  33 +       /*
  34 +        * Need to update the Ring buffer length according to the selected
  35 +        * baud rate and restart Rx DMA path.
  36 +        *
  37 +        * Since timer function acqures sport->port.lock, need to stop before
  38 +        * acquring same lock because otherwise del_timer_sync() can deadlock.
  39 +        */
  40 +       if (old && sport->lpuart_dma_rx_use) {
  41 +               del_timer_sync(&sport->lpuart_timer);
  42 +               lpuart_dma_rx_free(&sport->port);
  43 +       }
  44 +
  45         spin_lock_irqsave(&sport->port.lock, flags);
  46
  47         sport->port.read_status_mask = 0;
  48 @@ -1397,22 +1411,11 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
  49         /* restore control register */
  50         writeb(old_cr2, sport->port.membase + UARTCR2);
  51
  52 -       /*
  53 -        * If new baud rate is set, we will also need to update the Ring buffer
  54 -        * length according to the selected baud rate and restart Rx DMA path.
  55 -        */
  56 -       if (old) {
  57 -               if (sport->lpuart_dma_rx_use) {
  58 -                       del_timer_sync(&sport->lpuart_timer);
  59 -                       lpuart_dma_rx_free(&sport->port);
  60 -               }
  61 -
  62 -               if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
  63 -                       sport->lpuart_dma_rx_use = true;
  64 +       if (old && sport->lpuart_dma_rx_use) {
  65 +               if (!lpuart_start_rx_dma(sport))
  66                         rx_dma_timer_init(sport);
  67 -               } else {
  68 +               else
  69                         sport->lpuart_dma_rx_use = false;
  70 -               }
  71         }
  72
  73         spin_unlock_irqrestore(&sport->port.lock, flags);
  74 @@ -1640,6 +1643,13 @@ lpuart_console_write(struct console *co, const char *s, unsigned int count)
  75  {
  76         struct lpuart_port *sport = lpuart_ports[co->index];
  77         unsigned char  old_cr2, cr2;
  78 +       unsigned long flags;
  79 +       int locked = 1;
  80 +
  81 +       if (sport->port.sysrq || oops_in_progress)
  82 +               locked = spin_trylock_irqsave(&sport->port.lock, flags);
  83 +       else
  84 +               spin_lock_irqsave(&sport->port.lock, flags);
  85
  86         /* first save CR2 and then disable interrupts */
  87         cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
  88 @@ -1654,6 +1664,9 @@ lpuart_console_write(struct console *co, const char *s, unsigned int count)
  89                 barrier();
  90
  91         writeb(old_cr2, sport->port.membase + UARTCR2);
  92 +
  93 +       if (locked)
  94 +               spin_unlock_irqrestore(&sport->port.lock, flags);
  95  }
  96
  97  static void
  98 @@ -1661,6 +1674,13 @@ lpuart32_console_write(struct console *co, const char *s, unsigned int count)
  99  {
 100         struct lpuart_port *sport = lpuart_ports[co->index];
 101         unsigned long  old_cr, cr;
 102 +       unsigned long flags;
 103 +       int locked = 1;
 104 +
 105 +       if (sport->port.sysrq || oops_in_progress)
 106 +               locked = spin_trylock_irqsave(&sport->port.lock, flags);
 107 +       else
 108 +               spin_lock_irqsave(&sport->port.lock, flags);
 109
 110         /* first save CR2 and then disable interrupts */
 111         cr = old_cr = lpuart32_read(sport->port.membase + UARTCTRL);
 112 @@ -1675,6 +1695,9 @@ lpuart32_console_write(struct console *co, const char *s, unsigned int count)
 113                 barrier();
 114
 115         lpuart32_write(old_cr, sport->port.membase + UARTCTRL);
 116 +
 117 +       if (locked)
 118 +               spin_unlock_irqrestore(&sport->port.lock, flags);
 119  }
 120
 121  /*
 122 @@ -1899,9 +1922,13 @@ static int lpuart_probe(struct platform_device *pdev)
 123
 124         ret = of_alias_get_id(np, "serial");
 125         if (ret < 0) {
 126 -               dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
 127 -               return ret;
 128 +               ret = find_first_zero_bit(linemap, UART_NR);
 129 +               if (ret >= UART_NR) {
 130 +                       dev_err(&pdev->dev, "port line is full, add device failed\n");
 131 +                       return ret;
 132 +               }
 133         }
 134 +       set_bit(ret, linemap);
 135         sport->port.line = ret;
 136         sport->lpuart32 = of_device_is_compatible(np, "fsl,ls1021a-lpuart");
 137
 138 @@ -1983,6 +2010,7 @@ static int lpuart_remove(struct platform_device *pdev)
 139         struct lpuart_port *sport = platform_get_drvdata(pdev);
 140
 141         uart_remove_one_port(&lpuart_reg, &sport->port);
 142 +       clear_bit(sport->port.line, linemap);
 143
 144         clk_disable_unprepare(sport->clk);
 145
 146 @@ -2067,12 +2095,10 @@ static int lpuart_resume(struct device *dev)
 147
 148         if (sport->lpuart_dma_rx_use) {
 149                 if (sport->port.irq_wake) {
 150 -                       if (!lpuart_start_rx_dma(sport)) {
 151 -                               sport->lpuart_dma_rx_use = true;
 152 +                       if (!lpuart_start_rx_dma(sport))
 153                                 rx_dma_timer_init(sport);
 154 -                       } else {
 155 +                       else
 156                                 sport->lpuart_dma_rx_use = false;
 157 -                       }
 158                 }
 159         }
 160
 161 --
 162 2.14.1
 163