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 diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
  11 index 737b4c9..65ee974 100644
  12 --- a/drivers/serial/8250.c
  13 +++ b/drivers/serial/8250.c
  14 @@ -196,7 +196,7 @@ static const struct serial8250_config uart_config[] = {
  15         [PORT_16550A] = {
  16                 .name           = "16550A",
  17                 .fifo_size      = 16,
  18 -               .tx_loadsz      = 16,
  19 +               .tx_loadsz      = 8,
  20                 .fcr            = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
  21                 .flags          = UART_CAP_FIFO,
  22         },
  23 @@ -403,6 +403,10 @@ static unsigned int mem_serial_in(struct uart_port *p, int offset)
  24  static void mem_serial_out(struct uart_port *p, int offset, int value)
  25  {
  26         offset = map_8250_out_reg(p, offset) << p->regshift;
  27 +#if defined(CONFIG_JZSOC)
  28 +               if (offset == (UART_FCR << p->regshift))
  29 +                       value |= 0x10; /* set FCR.UUE */
  30 +#endif
  31         writeb(value, p->membase + offset);
  32  }
  33
  34 @@ -2215,6 +2219,83 @@ static void serial8250_shutdown(struct uart_port *port)
  35                 serial_unlink_irq_chain(up);
  36  }
  37
  38 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
  39 +static unsigned short quot1[3] = {0}; /* quot[0]:baud_div, quot[1]:umr, quot[2]:uacr */
  40 +static unsigned short * serial8250_get_divisor(struct uart_port *port, unsigned int baud)
  41 +{
  42 +       int err, sum, i, j;
  43 +       int a[12], b[12];
  44 +       unsigned short div, umr, uacr;
  45 +       unsigned short umr_best, div_best, uacr_best;
  46 +       long long t0, t1, t2, t3;
  47 +
  48 +       sum = 0;
  49 +       umr_best = div_best = uacr_best = 0;
  50 +       div = 1;
  51 +
  52 +       if ((port->uartclk % (16 * baud)) == 0) {
  53 +               quot1[0] = port->uartclk / (16 * baud);
  54 +               quot1[1] = 16;
  55 +               quot1[2] = 0;
  56 +               return quot1;
  57 +       }
  58 +
  59 +       while (1) {
  60 +               umr = port->uartclk / (baud * div);
  61 +               if (umr > 32) {
  62 +                       div++;
  63 +                       continue;
  64 +               }
  65 +               if (umr < 4) {
  66 +                       break;
  67 +               }
  68 +               for (i = 0; i < 12; i++) {
  69 +                       a[i] = umr;
  70 +                       b[i] = 0;
  71 +                       sum = 0;
  72 +                       for (j = 0; j <= i; j++) {
  73 +                               sum += a[j];
  74 +                       }
  75 +
  76 +                        /* the precision could be 1/2^(36) due to the value of t0 */
  77 +                       t0 = 0x1000000000LL;
  78 +                       t1 = (i + 1) * t0;
  79 +                       t2 = (sum * div) * t0;
  80 +                       t3 = div * t0;
  81 +                       do_div(t1, baud);
  82 +                       do_div(t2, port->uartclk);
  83 +                       do_div(t3, (2 * port->uartclk));
  84 +                       err = t1 - t2 - t3;
  85 +
  86 +                       if (err > 0) {
  87 +                               a[i] += 1;
  88 +                               b[i] = 1;
  89 +                       }
  90 +               }
  91 +
  92 +               uacr = 0;
  93 +               for (i = 0; i < 12; i++) {
  94 +                       if (b[i] == 1) {
  95 +                               uacr |= 1 << i;
  96 +                       }
  97 +               }
  98 +
  99 +                /* the best value of umr should be near 16, and the value of uacr should better be smaller */
 100 +               if (abs(umr - 16) < abs(umr_best - 16) || (abs(umr - 16) == abs(umr_best - 16) && uacr_best > uacr)) {
 101 +                       div_best = div;
 102 +                       umr_best = umr;
 103 +                       uacr_best = uacr;
 104 +               }
 105 +               div++;
 106 +       }
 107 +
 108 +       quot1[0] = div_best;
 109 +       quot1[1] = umr_best;
 110 +       quot1[2] = uacr_best;
 111 +
 112 +       return quot1;
 113 +}
 114 +#else
 115  static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
 116  {
 117         unsigned int quot;
 118 @@ -2234,6 +2315,7 @@ static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int
 119
 120         return quot;
 121  }
 122 +#endif
 123
 124  static void
 125  serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 126 @@ -2243,6 +2325,9 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 127         unsigned char cval, fcr = 0;
 128         unsigned long flags;
 129         unsigned int baud, quot;
 130 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
 131 +       unsigned short *quot1;
 132 +#endif
 133
 134         switch (termios->c_cflag & CSIZE) {
 135         case CS5:
 136 @@ -2277,7 +2362,12 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 137         baud = uart_get_baud_rate(port, termios, old,
 138                                   port->uartclk / 16 / 0xffff,
 139                                   port->uartclk / 16);
 140 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
 141 +       quot1 = serial8250_get_divisor(port, baud);
 142 +       quot = quot1[0]; /* not usefull, just let gcc happy */
 143 +#else
 144         quot = serial8250_get_divisor(port, baud);
 145 +#endif
 146
 147         /*
 148          * Oxford Semi 952 rev B workaround
 149 @@ -2355,6 +2445,10 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 150         if (up->capabilities & UART_CAP_UUE)
 151                 up->ier |= UART_IER_UUE | UART_IER_RTOIE;
 152
 153 +#ifdef CONFIG_JZSOC
 154 +       up->ier |= UART_IER_RTOIE; /* Set this flag, or very slow */
 155 +#endif
 156 +
 157         serial_out(up, UART_IER, up->ier);
 158
 159         if (up->capabilities & UART_CAP_EFR) {
 160 @@ -2389,7 +2483,15 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 161                 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
 162         }
 163
 164 +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730)
 165 +#define UART_UMR  9
 166 +#define UART_UACR 10
 167 +       serial_dl_write(up, quot1[0]);
 168 +       serial_outp(up, UART_UMR, quot1[1]);
 169 +       serial_outp(up, UART_UACR, quot1[2]);
 170 +#else
 171         serial_dl_write(up, quot);
 172 +#endif
 173
 174         /*
 175          * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
 176 --
 177 1.5.6.5
 178