powerpc/mpc5200: add rts/cts handling in PSC UART driver

Add RTS/CTS-support for the PSC of the MPC5200B. Tested with a Phytec
MPC5200B-IO.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/arch/powerpc/include/asm/mpc52xx_psc.h b/arch/powerpc/include/asm/mpc52xx_psc.h
index 8917ed6..a218da6 100644 (file)
--- a/arch/powerpc/include/asm/mpc52xx_psc.h
+++ b/arch/powerpc/include/asm/mpc52xx_psc.h
@@ -68,12 +68,20 @@
 #define MPC52xx_PSC_IMR_ORERR          0x1000
 #define MPC52xx_PSC_IMR_IPC            0x8000
 
-/* PSC input port change bit */
+/* PSC input port change bits */
 #define MPC52xx_PSC_CTS                        0x01
 #define MPC52xx_PSC_DCD                        0x02
 #define MPC52xx_PSC_D_CTS              0x10
 #define MPC52xx_PSC_D_DCD              0x20
 
+/* PSC acr bits */
+#define MPC52xx_PSC_IEC_CTS            0x01
+#define MPC52xx_PSC_IEC_DCD            0x02
+
+/* PSC output port bits */
+#define MPC52xx_PSC_OP_RTS             0x01
+#define MPC52xx_PSC_OP_RES             0x02
+
 /* PSC mode fields */
 #define MPC52xx_PSC_MODE_5_BITS                        0x00
 #define MPC52xx_PSC_MODE_6_BITS                        0x01
@@ -91,6 +99,7 @@
 #define MPC52xx_PSC_MODE_ONE_STOP_5_BITS       0x00
 #define MPC52xx_PSC_MODE_ONE_STOP              0x07
 #define MPC52xx_PSC_MODE_TWO_STOP              0x0f
+#define MPC52xx_PSC_MODE_TXCTS                 0x10
 
 #define MPC52xx_PSC_RFNUM_MASK 0x01ff
 

diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
index d82650d..d2a1fc2 100644 (file)
--- a/drivers/serial/mpc52xx_uart.c
+++ b/drivers/serial/mpc52xx_uart.c
@@ -429,14 +429,24 @@ mpc52xx_uart_tx_empty(struct uart_port *port)
 static void
 mpc52xx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-       /* Not implemented */
+       if (mctrl & TIOCM_RTS)
+               out_8(&PSC(port)->op1, MPC52xx_PSC_OP_RTS);
+       else
+               out_8(&PSC(port)->op0, MPC52xx_PSC_OP_RTS);
 }
 
 static unsigned int
 mpc52xx_uart_get_mctrl(struct uart_port *port)
 {
-       /* Not implemented */
-       return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+       unsigned int ret = TIOCM_DSR;
+       u8 status = in_8(&PSC(port)->mpc52xx_psc_ipcr);
+
+       if (!(status & MPC52xx_PSC_CTS))
+               ret |= TIOCM_CTS;
+       if (!(status & MPC52xx_PSC_DCD))
+               ret |= TIOCM_CAR;
+
+       return ret;
 }
 
 static void
@@ -479,7 +489,15 @@ mpc52xx_uart_stop_rx(struct uart_port *port)
 static void
 mpc52xx_uart_enable_ms(struct uart_port *port)
 {
-       /* Not implemented */
+       struct mpc52xx_psc __iomem *psc = PSC(port);
+
+       /* clear D_*-bits by reading them */
+       in_8(&psc->mpc52xx_psc_ipcr);
+       /* enable CTS and DCD as IPC interrupts */
+       out_8(&psc->mpc52xx_psc_acr, MPC52xx_PSC_IEC_CTS | MPC52xx_PSC_IEC_DCD);
+
+       port->read_status_mask |= MPC52xx_PSC_IMR_IPC;
+       out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
 }
 
 static void
@@ -580,6 +598,10 @@ mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
                        MPC52xx_PSC_MODE_ONE_STOP_5_BITS :
                        MPC52xx_PSC_MODE_ONE_STOP;
 
+       if (new->c_cflag & CRTSCTS) {
+               mr1 |= MPC52xx_PSC_MODE_RXRTS;
+               mr2 |= MPC52xx_PSC_MODE_TXCTS;
+       }
 
        baud = uart_get_baud_rate(port, new, old, 0, port->uartclk/16);
        quot = uart_get_divisor(port, baud);
@@ -617,6 +639,9 @@ mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
        out_8(&psc->ctur, ctr >> 8);
        out_8(&psc->ctlr, ctr & 0xff);
 
+       if (UART_ENABLE_MS(port, new->c_cflag))
+               mpc52xx_uart_enable_ms(port);
+
        /* Reenable TX & RX */
        out_8(&psc->command, MPC52xx_PSC_TX_ENABLE);
        out_8(&psc->command, MPC52xx_PSC_RX_ENABLE);
@@ -832,6 +857,7 @@ mpc52xx_uart_int(int irq, void *dev_id)
        struct uart_port *port = dev_id;
        unsigned long pass = ISR_PASS_LIMIT;
        unsigned int keepgoing;
+       u8 status;
 
        spin_lock(&port->lock);
 
@@ -848,6 +874,13 @@ mpc52xx_uart_int(int irq, void *dev_id)
                if (psc_ops->tx_rdy(port))
                        keepgoing |= mpc52xx_uart_int_tx_chars(port);
 
+               status = in_8(&PSC(port)->mpc52xx_psc_ipcr);
+               if (status & MPC52xx_PSC_D_DCD)
+                       uart_handle_dcd_change(port, !(status & MPC52xx_PSC_DCD));
+
+               if (status & MPC52xx_PSC_D_CTS)
+                       uart_handle_cts_change(port, !(status & MPC52xx_PSC_CTS));
+
                /* Limit number of iteration */
                if (!(--pass))
                        keepgoing = 0;