tty/8250_dw: Add support for OCTEON UARTS.

A few differences needed by OCTEON:

o These are DWC UARTS, but have USR at a different offset.

o OCTEON must have 64-bit wide register accesses, so we have OCTEON
  specific register accessors.

o No UCV register, so we hard code some properties.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-mips@linux-mips.org
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/5506/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index d07b6af3a9379db82927677a5915d9bae01d7874..a50c1d50ccbb861793f8d4ef74cab1861acdc125 100644 (file)
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -57,8 +57,30 @@ struct dw8250_data {
        int             last_lcr;
        int             line;
        struct clk      *clk;
+       u8              usr_reg;
+       bool            no_ucv;
 };
 
+static unsigned int dw8250_serial_inq(struct uart_port *p, int offset)
+{
+       offset <<= p->regshift;
+
+       return (u8)__raw_readq(p->membase + offset);
+}
+
+static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
+{
+       struct dw8250_data *d = p->private_data;
+
+       if (offset == UART_LCR)
+               d->last_lcr = value;
+
+       offset <<= p->regshift;
+       __raw_writeq(value, p->membase + offset);
+       dw8250_serial_inq(p, UART_LCR);
+}
+
+
 static void dw8250_serial_out(struct uart_port *p, int offset, int value)
 {
        struct dw8250_data *d = p->private_data;
@@ -104,7 +126,7 @@ static int dw8250_handle_irq(struct uart_port *p)
                return 1;
        } else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
                /* Clear the USR and write the LCR again. */
-               (void)p->serial_in(p, DW_UART_USR);
+               (void)p->serial_in(p, d->usr_reg);
                p->serial_out(p, UART_LCR, d->last_lcr);
 
                return 1;
@@ -125,12 +147,20 @@ dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
                pm_runtime_put_sync_suspend(port->dev);
 }
 
-static int dw8250_probe_of(struct uart_port *p)
+static int dw8250_probe_of(struct uart_port *p,
+                          struct dw8250_data *data)
 {
        struct device_node      *np = p->dev->of_node;
        u32                     val;
 
-       if (!of_property_read_u32(np, "reg-io-width", &val)) {
+       if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
+               p->serial_in = dw8250_serial_inq;
+               p->serial_out = dw8250_serial_outq;
+               p->flags = ASYNC_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
+               p->type = PORT_OCTEON;
+               data->usr_reg = 0x27;
+               data->no_ucv = true;
+       } else if (!of_property_read_u32(np, "reg-io-width", &val)) {
                switch (val) {
                case 1:
                        break;
@@ -259,6 +289,7 @@ static int dw8250_probe(struct platform_device *pdev)
        if (!data)
                return -ENOMEM;
 
+       data->usr_reg = DW_UART_USR;
        data->clk = devm_clk_get(&pdev->dev, NULL);
        if (!IS_ERR(data->clk)) {
                clk_prepare_enable(data->clk);
@@ -270,10 +301,8 @@ static int dw8250_probe(struct platform_device *pdev)
        uart.port.serial_out = dw8250_serial_out;
        uart.port.private_data = data;
 
-       dw8250_setup_port(&uart);
-
        if (pdev->dev.of_node) {
-               err = dw8250_probe_of(&uart.port);
+               err = dw8250_probe_of(&uart.port, data);
                if (err)
                        return err;
        } else if (ACPI_HANDLE(&pdev->dev)) {
@@ -284,6 +313,9 @@ static int dw8250_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
+       if (!data->no_ucv)
+               dw8250_setup_port(&uart);
+
        data->line = serial8250_register_8250_port(&uart);
        if (data->line < 0)
                return data->line;
@@ -362,6 +394,7 @@ static const struct dev_pm_ops dw8250_pm_ops = {
 
 static const struct of_device_id dw8250_of_match[] = {
        { .compatible = "snps,dw-apb-uart" },
+       { .compatible = "cavium,octeon-3860-uart" },
        { /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dw8250_of_match);