target/linux/xburst/patches-2.6.32/103-serial.patch

   1 From 5b3f9de4171368d9a99fa4c8b8b1bcc8505fb3c6 Mon Sep 17 00:00:00 2001
   2 From: Lars-Peter Clausen <lars@metafoo.de>
   3 Date: Mon, 11 Jan 2010 04:29:44 +0100
   4 Subject: [PATCH] /opt/Projects/openwrt/target/linux/xburst/patches-2.6.31/103-serial.patch
   5
   6 ---
   7  drivers/serial/8250.c |  104 ++++++++++++++++++++++++++++++++++++++++++++++++-
   8  1 files changed, 103 insertions(+), 1 deletions(-)
   9
  10 --- a/drivers/serial/8250.c
  11 +++ b/drivers/serial/8250.c
  12 @@ -199,7 +199,7 @@ static const struct serial8250_config ua
  13         [PORT_16550A] = {
  14                 .name           = "16550A",
  15                 .fifo_size      = 16,
  16 -               .tx_loadsz      = 16,
  17 +               .tx_loadsz      = 8,
  18                 .fcr            = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
  19                 .flags          = UART_CAP_FIFO,
  20         },
  21 @@ -406,6 +406,10 @@ static unsigned int mem_serial_in(struct
  22  static void mem_serial_out(struct uart_port *p, int offset, int value)
  23  {
  24         offset = map_8250_out_reg(p, offset) << p->regshift;
  25 +#if defined(CONFIG_JZSOC)
  26 +               if (offset == (UART_FCR << p->regshift))
  27 +                       value |= 0x10; /* set FCR.UUE */
  28 +#endif
  29         writeb(value, p->membase + offset);
  30  }
  31
  32 @@ -2214,6 +2218,83 @@ static void serial8250_shutdown(struct u
  33                 serial_unlink_irq_chain(up);
  34  }
  35
  36 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
  37 +static unsigned short quot1[3] = {0}; /* quot[0]:baud_div, quot[1]:umr, quot[2]:uacr */
  38 +static unsigned short * serial8250_get_divisor(struct uart_port *port, unsigned int baud)
  39 +{
  40 +       int err, sum, i, j;
  41 +       int a[12], b[12];
  42 +       unsigned short div, umr, uacr;
  43 +       unsigned short umr_best, div_best, uacr_best;
  44 +       long long t0, t1, t2, t3;
  45 +
  46 +       sum = 0;
  47 +       umr_best = div_best = uacr_best = 0;
  48 +       div = 1;
  49 +
  50 +       if ((port->uartclk % (16 * baud)) == 0) {
  51 +               quot1[0] = port->uartclk / (16 * baud);
  52 +               quot1[1] = 16;
  53 +               quot1[2] = 0;
  54 +               return quot1;
  55 +       }
  56 +
  57 +       while (1) {
  58 +               umr = port->uartclk / (baud * div);
  59 +               if (umr > 32) {
  60 +                       div++;
  61 +                       continue;
  62 +               }
  63 +               if (umr < 4) {
  64 +                       break;
  65 +               }
  66 +               for (i = 0; i < 12; i++) {
  67 +                       a[i] = umr;
  68 +                       b[i] = 0;
  69 +                       sum = 0;
  70 +                       for (j = 0; j <= i; j++) {
  71 +                               sum += a[j];
  72 +                       }
  73 +
  74 +                        /* the precision could be 1/2^(36) due to the value of t0 */
  75 +                       t0 = 0x1000000000LL;
  76 +                       t1 = (i + 1) * t0;
  77 +                       t2 = (sum * div) * t0;
  78 +                       t3 = div * t0;
  79 +                       do_div(t1, baud);
  80 +                       do_div(t2, port->uartclk);
  81 +                       do_div(t3, (2 * port->uartclk));
  82 +                       err = t1 - t2 - t3;
  83 +
  84 +                       if (err > 0) {
  85 +                               a[i] += 1;
  86 +                               b[i] = 1;
  87 +                       }
  88 +               }
  89 +
  90 +               uacr = 0;
  91 +               for (i = 0; i < 12; i++) {
  92 +                       if (b[i] == 1) {
  93 +                               uacr |= 1 << i;
  94 +                       }
  95 +               }
  96 +
  97 +                /* the best value of umr should be near 16, and the value of uacr should better be smaller */
  98 +               if (abs(umr - 16) < abs(umr_best - 16) || (abs(umr - 16) == abs(umr_best - 16) && uacr_best > uacr)) {
  99 +                       div_best = div;
 100 +                       umr_best = umr;
 101 +                       uacr_best = uacr;
 102 +               }
 103 +               div++;
 104 +       }
 105 +
 106 +       quot1[0] = div_best;
 107 +       quot1[1] = umr_best;
 108 +       quot1[2] = uacr_best;
 109 +
 110 +       return quot1;
 111 +}
 112 +#else
 113  static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
 114  {
 115         unsigned int quot;
 116 @@ -2233,6 +2314,7 @@ static unsigned int serial8250_get_divis
 117
 118         return quot;
 119  }
 120 +#endif
 121
 122  static void
 123  serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 124 @@ -2242,6 +2324,9 @@ serial8250_set_termios(struct uart_port
 125         unsigned char cval, fcr = 0;
 126         unsigned long flags;
 127         unsigned int baud, quot;
 128 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
 129 +       unsigned short *quot1;
 130 +#endif
 131
 132         switch (termios->c_cflag & CSIZE) {
 133         case CS5:
 134 @@ -2276,7 +2361,12 @@ serial8250_set_termios(struct uart_port
 135         baud = uart_get_baud_rate(port, termios, old,
 136                                   port->uartclk / 16 / 0xffff,
 137                                   port->uartclk / 16);
 138 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
 139 +       quot1 = serial8250_get_divisor(port, baud);
 140 +       quot = quot1[0]; /* not usefull, just let gcc happy */
 141 +#else
 142         quot = serial8250_get_divisor(port, baud);
 143 +#endif
 144
 145         /*
 146          * Oxford Semi 952 rev B workaround
 147 @@ -2354,6 +2444,10 @@ serial8250_set_termios(struct uart_port
 148         if (up->capabilities & UART_CAP_UUE)
 149                 up->ier |= UART_IER_UUE | UART_IER_RTOIE;
 150
 151 +#ifdef CONFIG_JZSOC
 152 +       up->ier |= UART_IER_RTOIE; /* Set this flag, or very slow */
 153 +#endif
 154 +
 155         serial_out(up, UART_IER, up->ier);
 156
 157         if (up->capabilities & UART_CAP_EFR) {
 158 @@ -2388,7 +2482,15 @@ serial8250_set_termios(struct uart_port
 159                 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
 160         }
 161
 162 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
 163 +#define UART_UMR  9
 164 +#define UART_UACR 10
 165 +       serial_dl_write(up, quot1[0]);
 166 +       serial_outp(up, UART_UMR, quot1[1]);
 167 +       serial_outp(up, UART_UACR, quot1[2]);
 168 +#else
 169         serial_dl_write(up, quot);
 170 +#endif
 171
 172         /*
 173          * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR