From 35d6fcb8cc04d368abef00b00e6af04b8c71ba46 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 19 Aug 2009 14:54:02 +0200 Subject: [PATCH] serial --- drivers/serial/8250.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 103 insertions(+), 1 deletions(-) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index fb867a9..d8784c3 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -194,7 +194,7 @@ static const struct serial8250_config uart_config[] = { [PORT_16550A] = { .name = "16550A", .fifo_size = 16, - .tx_loadsz = 16, + .tx_loadsz = 8, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO, }, @@ -401,6 +401,10 @@ static unsigned int mem_serial_in(struct uart_port *p, int offset) static void mem_serial_out(struct uart_port *p, int offset, int value) { offset = map_8250_out_reg(p, offset) << p->regshift; +#if defined(CONFIG_JZSOC) + if (offset == (UART_FCR << p->regshift)) + value |= 0x10; /* set FCR.UUE */ +#endif writeb(value, p->membase + offset); } @@ -2213,6 +2217,83 @@ static void serial8250_shutdown(struct uart_port *port) serial_unlink_irq_chain(up); } +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730) +static unsigned short quot1[3] = {0}; /* quot[0]:baud_div, quot[1]:umr, quot[2]:uacr */ +static unsigned short * serial8250_get_divisor(struct uart_port *port, unsigned int baud) +{ + int err, sum, i, j; + int a[12], b[12]; + unsigned short div, umr, uacr; + unsigned short umr_best, div_best, uacr_best; + long long t0, t1, t2, t3; + + sum = 0; + umr_best = div_best = uacr_best = 0; + div = 1; + + if ((port->uartclk % (16 * baud)) == 0) { + quot1[0] = port->uartclk / (16 * baud); + quot1[1] = 16; + quot1[2] = 0; + return quot1; + } + + while (1) { + umr = port->uartclk / (baud * div); + if (umr > 32) { + div++; + continue; + } + if (umr < 4) { + break; + } + for (i = 0; i < 12; i++) { + a[i] = umr; + b[i] = 0; + sum = 0; + for (j = 0; j <= i; j++) { + sum += a[j]; + } + + /* the precision could be 1/2^(36) due to the value of t0 */ + t0 = 0x1000000000LL; + t1 = (i + 1) * t0; + t2 = (sum * div) * t0; + t3 = div * t0; + do_div(t1, baud); + do_div(t2, port->uartclk); + do_div(t3, (2 * port->uartclk)); + err = t1 - t2 - t3; + + if (err > 0) { + a[i] += 1; + b[i] = 1; + } + } + + uacr = 0; + for (i = 0; i < 12; i++) { + if (b[i] == 1) { + uacr |= 1 << i; + } + } + + /* the best value of umr should be near 16, and the value of uacr should better be smaller */ + if (abs(umr - 16) < abs(umr_best - 16) || (abs(umr - 16) == abs(umr_best - 16) && uacr_best > uacr)) { + div_best = div; + umr_best = umr; + uacr_best = uacr; + } + div++; + } + + quot1[0] = div_best; + quot1[1] = umr_best; + quot1[2] = uacr_best; + + return quot1; +} +#else static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud) { unsigned int quot; @@ -2232,6 +2313,7 @@ static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int return quot; } +#endif static void serial8250_set_termios(struct uart_port *port, struct ktermios *termios, @@ -2241,6 +2323,9 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios, unsigned char cval, fcr = 0; unsigned long flags; unsigned int baud, quot; +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730) + unsigned short *quot1; +#endif switch (termios->c_cflag & CSIZE) { case CS5: @@ -2273,7 +2358,12 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios, * Ask the core to calculate the divisor for us. */ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730) + quot1 = serial8250_get_divisor(port, baud); + quot = quot1[0]; /* not usefull, just let gcc happy */ +#else quot = serial8250_get_divisor(port, baud); +#endif /* * Oxford Semi 952 rev B workaround @@ -2351,6 +2441,10 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios, if (up->capabilities & UART_CAP_UUE) up->ier |= UART_IER_UUE | UART_IER_RTOIE; +#ifdef CONFIG_JZSOC + up->ier |= UART_IER_RTOIE; /* Set this flag, or very slow */ +#endif + serial_out(up, UART_IER, up->ier); if (up->capabilities & UART_CAP_EFR) { @@ -2385,7 +2479,15 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios, serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */ } +#if defined(CONFIG_JZSOC) && !defined(CONFIG_SOC_JZ4730) +#define UART_UMR 9 +#define UART_UACR 10 + serial_dl_write(up, quot1[0]); + serial_outp(up, UART_UMR, quot1[1]); + serial_outp(up, UART_UACR, quot1[2]); +#else serial_dl_write(up, quot); +#endif /* * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR -- 1.5.6.5