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From 6e138e4c3bfa5fb272d215107d85385456281ceb Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Sat, 24 Apr 2010 12:19:30 +0200
Subject: [PATCH] Add jz4740 serial driver
---
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 2b1ea3d..4c41c57 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -200,7 +200,7 @@ 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,
},
@@ -407,6 +407,10 @@ 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);
}
@@ -2209,6 +2213,83 @@ 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;
@@ -2228,6 +2309,7 @@ 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,
@@ -2237,6 +2319,9 @@ 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:
@@ -2271,7 +2356,12 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
baud = uart_get_baud_rate(port, termios, old,
port->uartclk / 16 / 0xffff,
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
@@ -2349,6 +2439,10 @@ 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) {
@@ -2383,7 +2477,15 @@ 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
|
