[PATCH] serial: 8250_dw: Use device tree match data

[Emil Renner Berthing <kernel@esmil.dk>]

..rather than multiple calls to of_device_is_compatible().

Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
---

Hi Miquel,

> > > > --- a/drivers/tty/serial/8250/8250_dma.c
> > > > +++ b/drivers/tty/serial/8250/8250_dma.c =20
> > > =20
> > > > @@ -501,6 +589,8 @@ static int dw8250_probe(struct platform_device *p=
> dev)
> > > >                 data->msr_mask_off |=3D UART_MSR_TERI;
> > > >         }
> > > >
> > > > +       data->is_rzn1 =3D of_device_is_compatible(dev->of_node, "rene=
> sas,rzn1-uart"); =20
> > >
> > > Explicit checks for compatible values are frowned upon if you have
> > > a match table.
> > > Please handle this through of_device.data, cfr. the various quirks. =20
> >=20
> > Oops, these are not yet upstream, but present in my tree due to including
> > support for StarLight, cfr.
> > https://github.com/esmil/linux/commits/visionfive/drivers/tty/serial/8250=
> /8250_dw.c
> 
> Oh thanks for pointing it! Too bad that these quirks were not
> introduced inside a wider structure, I think it's always a must even if
> there is only one parameter there. Anyway, I'll introduce a wider
> specific structure and use it.

For reference this is the patch I wrote for the StarFive JH7100 tree.
Feel free to use it or do something better as you see fit.

/Emil

 drivers/tty/serial/8250/8250_dw.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 1769808031c5..f564a019a7be 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -37,6 +37,11 @@
 /* DesignWare specific register fields */
 #define DW_UART_MCR_SIRE		BIT(6)
 
+/* Quirks */
+#define DW_UART_QUIRK_OCTEON		BIT(0)
+#define DW_UART_QUIRK_ARMADA_38X	BIT(1)
+#define DW_UART_QUIRK_SKIP_SET_RATE	BIT(2)
+
 struct dw8250_data {
 	struct dw8250_port_data	data;
 
@@ -389,6 +394,7 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 	struct device_node *np = p->dev->of_node;
 
 	if (np) {
+		unsigned long quirks = (unsigned long)of_device_get_match_data(p->dev);
 		int id;
 
 		/* get index of serial line, if found in DT aliases */
@@ -396,7 +402,7 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 		if (id >= 0)
 			p->line = id;
 #ifdef CONFIG_64BIT
-		if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
+		if (quirks & DW_UART_QUIRK_OCTEON) {
 			p->serial_in = dw8250_serial_inq;
 			p->serial_out = dw8250_serial_outq;
 			p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
@@ -412,9 +418,9 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 			p->serial_out = dw8250_serial_out32be;
 		}
 
-		if (of_device_is_compatible(np, "marvell,armada-38x-uart"))
+		if (quirks & DW_UART_QUIRK_ARMADA_38X)
 			p->serial_out = dw8250_serial_out38x;
-		if (of_device_is_compatible(np, "starfive,jh7100-uart"))
+		if (quirks & DW_UART_QUIRK_SKIP_SET_RATE)
 			p->set_termios = dw8250_do_set_termios;
 
 	} else if (acpi_dev_present("APMC0D08", NULL, -1)) {
@@ -695,10 +701,10 @@ 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" },
-	{ .compatible = "marvell,armada-38x-uart" },
+	{ .compatible = "cavium,octeon-3860-uart", .data = (void *)DW_UART_QUIRK_OCTEON },
+	{ .compatible = "marvell,armada-38x-uart", .data = (void *)DW_UART_QUIRK_ARMADA_38X },
 	{ .compatible = "renesas,rzn1-uart" },
-	{ .compatible = "starfive,jh7100-uart" },
+	{ .compatible = "starfive,jh7100-uart",    .data = (void *)DW_UART_QUIRK_SKIP_SET_RATE },
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dw8250_of_match);
-- 
2.35.1