[PATCH 1/2] ARM: PL011 TX/RX split of LCR for ST-Ericssons derivative
Linus Walleij
linus.walleij at stericsson.com
Tue Jun 1 05:47:59 EDT 2010
From: Marcin Mielczarczyk <marcin.mielczarczyk at tieto.com>
In the ST-Ericsson version of the PL011 the TX and RX have different
control registers.
Cc: Alessandro Rubini <rubini at unipv.it>
Signed-off-by: Marcin Mielczarczyk <marcin.mielczarczyk at tieto.com>
Signed-off-by: Linus Walleij <linus.walleij at stericsson.com>
---
drivers/serial/amba-pl011.c | 61 +++++++++++++++++++++++++++++++++++--------
include/linux/amba/serial.h | 2 +
2 files changed, 52 insertions(+), 11 deletions(-)
diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index eb4cb48..7f0c271 100644
--- a/drivers/serial/amba-pl011.c
+++ b/drivers/serial/amba-pl011.c
@@ -69,9 +69,11 @@
struct uart_amba_port {
struct uart_port port;
struct clk *clk;
- unsigned int im; /* interrupt mask */
+ unsigned int im; /* interrupt mask */
unsigned int old_status;
- unsigned int ifls; /* vendor-specific */
+ unsigned int ifls; /* vendor-specific */
+ unsigned int lcrh_tx; /* vendor-specific */
+ unsigned int lcrh_rx; /* vendor-specific */
bool autorts;
};
@@ -79,16 +81,22 @@ struct uart_amba_port {
struct vendor_data {
unsigned int ifls;
unsigned int fifosize;
+ unsigned int lcrh_tx;
+ unsigned int lcrh_rx;
};
static struct vendor_data vendor_arm = {
.ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
.fifosize = 16,
+ .lcrh_tx = UART011_LCRH,
+ .lcrh_rx = UART011_LCRH,
};
static struct vendor_data vendor_st = {
.ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
.fifosize = 64,
+ .lcrh_tx = ST_UART011_LCRH_TX,
+ .lcrh_rx = ST_UART011_LCRH_RX,
};
static void pl011_stop_tx(struct uart_port *port)
@@ -327,12 +335,12 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
unsigned int lcr_h;
spin_lock_irqsave(&uap->port.lock, flags);
- lcr_h = readw(uap->port.membase + UART011_LCRH);
+ lcr_h = readw(uap->port.membase + uap->lcrh_tx);
if (break_state == -1)
lcr_h |= UART01x_LCRH_BRK;
else
lcr_h &= ~UART01x_LCRH_BRK;
- writew(lcr_h, uap->port.membase + UART011_LCRH);
+ writew(lcr_h, uap->port.membase + uap->lcrh_tx);
spin_unlock_irqrestore(&uap->port.lock, flags);
}
@@ -393,7 +401,17 @@ static int pl011_startup(struct uart_port *port)
writew(cr, uap->port.membase + UART011_CR);
writew(0, uap->port.membase + UART011_FBRD);
writew(1, uap->port.membase + UART011_IBRD);
- writew(0, uap->port.membase + UART011_LCRH);
+ writew(0, uap->port.membase + uap->lcrh_rx);
+ if (uap->lcrh_tx != uap->lcrh_rx) {
+ int i;
+ /*
+ * Wait 10 PCLKs before writing LCRH_TX register,
+ * to get this delay write read only register 10 times
+ */
+ for (i = 0; i < 10; ++i)
+ writew(0xff, uap->port.membase + UART011_MIS);
+ writew(0, uap->port.membase + uap->lcrh_tx);
+ }
writew(0, uap->port.membase + UART01x_DR);
while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY)
barrier();
@@ -422,10 +440,19 @@ static int pl011_startup(struct uart_port *port)
return retval;
}
+static void pl011_shutdown_channel(struct uart_amba_port *uap,
+ unsigned int lcrh)
+{
+ unsigned long val;
+
+ val = readw(uap->port.membase + lcrh);
+ val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
+ writew(val, uap->port.membase + lcrh);
+}
+
static void pl011_shutdown(struct uart_port *port)
{
struct uart_amba_port *uap = (struct uart_amba_port *)port;
- unsigned long val;
/*
* disable all interrupts
@@ -450,9 +477,9 @@ static void pl011_shutdown(struct uart_port *port)
/*
* disable break condition and fifos
*/
- val = readw(uap->port.membase + UART011_LCRH);
- val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
- writew(val, uap->port.membase + UART011_LCRH);
+ pl011_shutdown_channel(uap, uap->lcrh_rx);
+ if (uap->lcrh_rx != uap->lcrh_tx)
+ pl011_shutdown_channel(uap, uap->lcrh_tx);
/*
* Shut down the clock producer
@@ -561,7 +588,17 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
* NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
* ----------^----------^----------^----------^-----
*/
- writew(lcr_h, port->membase + UART011_LCRH);
+ writew(lcr_h, port->membase + uap->lcrh_rx);
+ if (uap->lcrh_rx != uap->lcrh_tx) {
+ int i;
+ /*
+ * Wait 10 PCLKs before writing LCRH_TX register,
+ * to get this delay write read only register 10 times
+ */
+ for (i = 0; i < 10; ++i)
+ writew(0xff, uap->port.membase + UART011_MIS);
+ writew(lcr_h, port->membase + uap->lcrh_tx);
+ }
writew(old_cr, port->membase + UART011_CR);
spin_unlock_irqrestore(&port->lock, flags);
@@ -688,7 +725,7 @@ pl011_console_get_options(struct uart_amba_port *uap, int *baud,
if (readw(uap->port.membase + UART011_CR) & UART01x_CR_UARTEN) {
unsigned int lcr_h, ibrd, fbrd;
- lcr_h = readw(uap->port.membase + UART011_LCRH);
+ lcr_h = readw(uap->port.membase + uap->lcrh_tx);
*parity = 'n';
if (lcr_h & UART01x_LCRH_PEN) {
@@ -800,6 +837,8 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id)
}
uap->ifls = vendor->ifls;
+ uap->lcrh_rx = vendor->lcrh_rx;
+ uap->lcrh_tx = vendor->lcrh_tx;
uap->port.dev = &dev->dev;
uap->port.mapbase = dev->res.start;
uap->port.membase = base;
diff --git a/include/linux/amba/serial.h b/include/linux/amba/serial.h
index 5a5a7fd..cf3cb61 100644
--- a/include/linux/amba/serial.h
+++ b/include/linux/amba/serial.h
@@ -38,10 +38,12 @@
#define UART01x_FR 0x18 /* Flag register (Read only). */
#define UART010_IIR 0x1C /* Interrupt indentification register (Read). */
#define UART010_ICR 0x1C /* Interrupt clear register (Write). */
+#define ST_UART011_LCRH_RX 0x1C /* Rx line control register. */
#define UART01x_ILPR 0x20 /* IrDA low power counter register. */
#define UART011_IBRD 0x24 /* Integer baud rate divisor register. */
#define UART011_FBRD 0x28 /* Fractional baud rate divisor register. */
#define UART011_LCRH 0x2c /* Line control register. */
+#define ST_UART011_LCRH_TX 0x2c /* Tx Line control register. */
#define UART011_CR 0x30 /* Control register. */
#define UART011_IFLS 0x34 /* Interrupt fifo level select. */
#define UART011_IMSC 0x38 /* Interrupt mask. */
--
1.6.3.3
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