diff options
Diffstat (limited to 'meta/packages/linux/linux-rp-2.6.22/serial-add-support-for-non-standard-xtals-to-16c950-driver.patch')
| -rw-r--r-- | meta/packages/linux/linux-rp-2.6.22/serial-add-support-for-non-standard-xtals-to-16c950-driver.patch | 155 |
1 files changed, 0 insertions, 155 deletions
diff --git a/meta/packages/linux/linux-rp-2.6.22/serial-add-support-for-non-standard-xtals-to-16c950-driver.patch b/meta/packages/linux/linux-rp-2.6.22/serial-add-support-for-non-standard-xtals-to-16c950-driver.patch deleted file mode 100644 index b513ba146..000000000 --- a/meta/packages/linux/linux-rp-2.6.22/serial-add-support-for-non-standard-xtals-to-16c950-driver.patch +++ /dev/null @@ -1,155 +0,0 @@ - -From: Petr Vandrovec <vandrove@vc.cvut.cz> - -Patch below adds support for using different prescaler than 16 for 16c950 -chips. This is needed for using Fujitsu-Siemens Connect2Air compact-flash -card, which comes (apparently) with 806kHz clocks, and so you have to -program prescaler for division by 7, and DLAB to 1, to get 115200Bd. - -To get card properly running you also have to add lines below to -/etc/pcmcia/serial.opts so kernel knows that base speed is not 115200 but -50400 (50400 * 16 = 806400; 806400 / 7 = 115200). As I've found no code -specifying baud_rate in serial_cs, I assume that specifying it in -serial.opts is right way to do this type of things. - -Patch also fixes problem that for UPF_MAGIC_MULTIPLIER maximum possible -baud rate passed to uart code was uartclk / 16 while correct value for -these devices (and for 16c950) is uartclk / 4. - -Patch also fixes problem that for UPF_MAGIC_MULTIPLIER devices with -baud_rate 19200 or 9600 spd_cust did not work correctly. Not that such -devices exist, but we should not ignore spd_cust, user probably knows why -he asked for spd_cust. - -serial.opts: - -case "$MANFID-$FUNCID-$PRODID_1-$PRODID_2-$PRODID_3-$PRODID_4" in -'0279,950b-2-GPRS Modem---') - SERIAL_OPTS="baud_base 50400" - ;; -esac - -Cc: David Woodhouse <dwmw2@infradead.org> -Signed-off-by: Andrew Morton <akpm@osdl.org> ---- - - drivers/serial/8250.c | 82 +++++++++++++++++++++++++++++++++++++++----------- - 1 file changed, 64 insertions(+), 18 deletions(-) - -Index: linux-2.6.21/drivers/serial/8250.c -=================================================================== ---- linux-2.6.21.orig/drivers/serial/8250.c 2007-07-01 16:59:52.000000000 +0100 -+++ linux-2.6.21/drivers/serial/8250.c 2007-07-01 17:01:21.000000000 +0100 -@@ -1964,24 +1964,58 @@ static void serial8250_shutdown(struct u - serial_unlink_irq_chain(up); - } - --static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud) -+static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud, -+ unsigned int *prescaler) - { -- unsigned int quot; -- -- /* -- * Handle magic divisors for baud rates above baud_base on -- * SMSC SuperIO chips. -+ /* -+ * Use special handling only if user did not supply its own divider. -+ * spd_cust is defined in terms of baud_base, so always use default -+ * prescaler when spd_cust is requested. - */ -- if ((port->flags & UPF_MAGIC_MULTIPLIER) && -- baud == (port->uartclk/4)) -- quot = 0x8001; -- else if ((port->flags & UPF_MAGIC_MULTIPLIER) && -- baud == (port->uartclk/8)) -- quot = 0x8002; -- else -- quot = uart_get_divisor(port, baud); - -- return quot; -+ *prescaler = 16; -+ if (baud != 38400 || (port->flags & UPF_SPD_MASK) != UPF_SPD_CUST) { -+ unsigned int quot = port->uartclk / baud; -+ -+ /* -+ * Handle magic divisors for baud rates above baud_base on -+ * SMSC SuperIO chips. -+ */ -+ if (port->flags & UPF_MAGIC_MULTIPLIER) { -+ if (quot == 4) { -+ return 0x8001; -+ } else if (quot == 8) { -+ return 0x8002; -+ } -+ } -+ if (port->type == PORT_16C950) { -+ /* -+ * This computes TCR value (4 to 16), not CPR value (which can -+ * be between 1.000 and 31.875) - chip I have uses XTAL of -+ * 806400Hz, and so a division by 7 is required to get 115200Bd. -+ * I'm leaving CPR disabled for now, until someone will -+ * hit even more exotic XTAL (it is needed to get 500kbps -+ * or 1000kbps from 18.432MHz XTAL, but I have no device -+ * which would benefit from doing that). -+ * -+ * If we can use divide by 16, use it. Otherwise look for -+ * better prescaler, from 15 to 4. If quotient cannot -+ * be divided by any integer value between 4 and 15, use 4. -+ */ -+ if (quot & 0x0F) { -+ unsigned int div; -+ -+ for (div = 15; div > 4; div--) { -+ if (quot % div == 0) { -+ break; -+ } -+ } -+ *prescaler = div; -+ return quot / div; -+ } -+ } -+ } -+ return uart_get_divisor(port, baud); - } - - static void -@@ -1991,7 +2025,7 @@ serial8250_set_termios(struct uart_port - struct uart_8250_port *up = (struct uart_8250_port *)port; - unsigned char cval, fcr = 0; - unsigned long flags; -- unsigned int baud, quot; -+ unsigned int baud, quot, prescaler; - - switch (termios->c_cflag & CSIZE) { - case CS5: -@@ -2023,8 +2057,13 @@ serial8250_set_termios(struct uart_port - /* - * Ask the core to calculate the divisor for us. - */ -- baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); -- quot = serial8250_get_divisor(port, baud); -+ if (port->type == PORT_16C950 || (port->flags & UPF_MAGIC_MULTIPLIER)) { -+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/4); -+ } else { -+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); -+ } -+ quot = serial8250_get_divisor(port, baud, &prescaler); -+ - - /* - * Oxford Semi 952 rev B workaround -@@ -2139,6 +2178,13 @@ serial8250_set_termios(struct uart_port - serial_dl_write(up, quot); - - /* -+ * Program prescaler for 16C950 chips. -+ */ -+ if (up->port.type == PORT_16C950) { -+ serial_icr_write(up, UART_TCR, prescaler == 16 ? 0 : prescaler); -+ } -+ -+ /* - * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR - * is written without DLAB set, this mode will be disabled. - */ |