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

   1 From c35aec61e5bb0faafb2847a0d750ebd7345a4b0f Mon Sep 17 00:00:00 2001
   2 From: Yangbo Lu <yangbo.lu@nxp.com>
   3 Date: Wed, 17 Jan 2018 15:40:24 +0800
   4 Subject: [PATCH 28/30] tty: serial: support layerscape
   5
   6 This is an 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 --- a/drivers/tty/serial/fsl_lpuart.c
  17 +++ b/drivers/tty/serial/fsl_lpuart.c
  18 @@ -231,6 +231,8 @@
  19  #define DEV_NAME       "ttyLP"
  20  #define UART_NR                6
  21
  22 +static DECLARE_BITMAP(linemap, UART_NR);
  23 +
  24  struct lpuart_port {
  25         struct uart_port        port;
  26         struct clk              *clk;
  27 @@ -1351,6 +1353,18 @@ lpuart_set_termios(struct uart_port *por
  28         /* ask the core to calculate the divisor */
  29         baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
  30
  31 +       /*
  32 +        * Need to update the Ring buffer length according to the selected
  33 +        * baud rate and restart Rx DMA path.
  34 +        *
  35 +        * Since timer function acqures sport->port.lock, need to stop before
  36 +        * acquring same lock because otherwise del_timer_sync() can deadlock.
  37 +        */
  38 +       if (old && sport->lpuart_dma_rx_use) {
  39 +               del_timer_sync(&sport->lpuart_timer);
  40 +               lpuart_dma_rx_free(&sport->port);
  41 +       }
  42 +
  43         spin_lock_irqsave(&sport->port.lock, flags);
  44
  45         sport->port.read_status_mask = 0;
  46 @@ -1400,22 +1414,11 @@ lpuart_set_termios(struct uart_port *por
  47         /* restore control register */
  48         writeb(old_cr2, sport->port.membase + UARTCR2);
  49
  50 -       /*
  51 -        * If new baud rate is set, we will also need to update the Ring buffer
  52 -        * length according to the selected baud rate and restart Rx DMA path.
  53 -        */
  54 -       if (old) {
  55 -               if (sport->lpuart_dma_rx_use) {
  56 -                       del_timer_sync(&sport->lpuart_timer);
  57 -                       lpuart_dma_rx_free(&sport->port);
  58 -               }
  59 -
  60 -               if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
  61 -                       sport->lpuart_dma_rx_use = true;
  62 +       if (old && sport->lpuart_dma_rx_use) {
  63 +               if (!lpuart_start_rx_dma(sport))
  64                         rx_dma_timer_init(sport);
  65 -               } else {
  66 +               else
  67                         sport->lpuart_dma_rx_use = false;
  68 -               }
  69         }
  70
  71         spin_unlock_irqrestore(&sport->port.lock, flags);
  72 @@ -1645,6 +1648,13 @@ lpuart_console_write(struct console *co,
  73  {
  74         struct lpuart_port *sport = lpuart_ports[co->index];
  75         unsigned char  old_cr2, cr2;
  76 +       unsigned long flags;
  77 +       int locked = 1;
  78 +
  79 +       if (sport->port.sysrq || oops_in_progress)
  80 +               locked = spin_trylock_irqsave(&sport->port.lock, flags);
  81 +       else
  82 +               spin_lock_irqsave(&sport->port.lock, flags);
  83
  84         /* first save CR2 and then disable interrupts */
  85         cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
  86 @@ -1659,6 +1669,9 @@ lpuart_console_write(struct console *co,
  87                 barrier();
  88
  89         writeb(old_cr2, sport->port.membase + UARTCR2);
  90 +
  91 +       if (locked)
  92 +               spin_unlock_irqrestore(&sport->port.lock, flags);
  93  }
  94
  95  static void
  96 @@ -1666,6 +1679,13 @@ lpuart32_console_write(struct console *c
  97  {
  98         struct lpuart_port *sport = lpuart_ports[co->index];
  99         unsigned long  old_cr, cr;
 100 +       unsigned long flags;
 101 +       int locked = 1;
 102 +
 103 +       if (sport->port.sysrq || oops_in_progress)
 104 +               locked = spin_trylock_irqsave(&sport->port.lock, flags);
 105 +       else
 106 +               spin_lock_irqsave(&sport->port.lock, flags);
 107
 108         /* first save CR2 and then disable interrupts */
 109         cr = old_cr = lpuart32_read(sport->port.membase + UARTCTRL);
 110 @@ -1680,6 +1700,9 @@ lpuart32_console_write(struct console *c
 111                 barrier();
 112
 113         lpuart32_write(old_cr, sport->port.membase + UARTCTRL);
 114 +
 115 +       if (locked)
 116 +               spin_unlock_irqrestore(&sport->port.lock, flags);
 117  }
 118
 119  /*
 120 @@ -1904,13 +1927,13 @@ static int lpuart_probe(struct platform_
 121
 122         ret = of_alias_get_id(np, "serial");
 123         if (ret < 0) {
 124 -               dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
 125 -               return ret;
 126 -       }
 127 -       if (ret >= ARRAY_SIZE(lpuart_ports)) {
 128 -               dev_err(&pdev->dev, "serial%d out of range\n", ret);
 129 -               return -EINVAL;
 130 +               ret = find_first_zero_bit(linemap, UART_NR);
 131 +               if (ret >= UART_NR) {
 132 +                       dev_err(&pdev->dev, "port line is full, add device failed\n");
 133 +                       return ret;
 134 +               }
 135         }
 136 +       set_bit(ret, linemap);
 137         sport->port.line = ret;
 138         sport->lpuart32 = of_device_is_compatible(np, "fsl,ls1021a-lpuart");
 139
 140 @@ -1992,6 +2015,7 @@ static int lpuart_remove(struct platform
 141         struct lpuart_port *sport = platform_get_drvdata(pdev);
 142
 143         uart_remove_one_port(&lpuart_reg, &sport->port);
 144 +       clear_bit(sport->port.line, linemap);
 145
 146         clk_disable_unprepare(sport->clk);
 147
 148 @@ -2076,12 +2100,10 @@ static int lpuart_resume(struct device *
 149
 150         if (sport->lpuart_dma_rx_use) {
 151                 if (sport->port.irq_wake) {
 152 -                       if (!lpuart_start_rx_dma(sport)) {
 153 -                               sport->lpuart_dma_rx_use = true;
 154 +                       if (!lpuart_start_rx_dma(sport))
 155                                 rx_dma_timer_init(sport);
 156 -                       } else {
 157 +                       else
 158                                 sport->lpuart_dma_rx_use = false;
 159 -                       }
 160                 }
 161         }
 162