realtek: rtl931x: Add SPI_CTRL0 as pinmux

The RTL931x has next to its SPI flash controller a SPI master interface. It
is connected to

* SPI_CS#[1,0]: AH22 , AK22 (aka: GPIO 12, 11)
* SPI_CLK:      AL23 (aka: GPIO 8)
* SPI_MISO:     AM23 (aka: GPIO 9)
* SPI_MOSI:     AL22 (aka: GPIO 10)

It is not the same as the SPI flash controller which uses pins:

* SPI_CS#[1,0]: B24, A24
* SPI_SCLK:     A23
* SPI_SDI/SIO0: B21
* SPO_SDO_SIO1: B21
* SPI_SIO2:     A22
* SPI_SIO3:     B22
* SPI_RSTN:     B23

As shown above, the SPI master controller shares its pin with GPIO 8, 9,
10, 11, 12. In some upcoming devices (like the Plasma Cloud PSX28/ESX28),
they will be used for SFP cage signaling. These pins must therefore be
switched manually to the GPIO mode.

The SPI_CTRL0 register provides all necessary configuration to enforce the
GPIO mode of the pins. And until more requirements (and a correct driver)
for the SPI master controller arise, it is therefore possible to use
pinctrl-single to configure it using the devicetree.

Previously the ethernet driver did configure the SPI master controller for
31.25 MHz. It is unknown for which kind of device this was originally made
and what was actually connected there. But this manual write to the
register conflicts potentially with the write of the pinctrl driver to the
same register. Luckily, we don't need this SPI speed configuration in the
ethernet driver. Still, to allow this device an easy migration, the
`spi0-31mhz` configuration was already prepared.

Signed-off-by: Sven Eckelmann <se@simonwunderlich.de>
Link: https://github.com/openwrt/openwrt/pull/20263
Signed-off-by: Robert Marko <robimarko@gmail.com>

diff --git a/target/linux/realtek/dts/rtl931x.dtsi b/target/linux/realtek/dts/rtl931x.dtsi
index eeda87ef2386f37d6e66c78d01f8d8aff3c4ac2d..d754ebd5a79a1a9d5c8fe11929604dd95ffccc04 100644 (file)
--- a/target/linux/realtek/dts/rtl931x.dtsi
+++ b/target/linux/realtek/dts/rtl931x.dtsi
@@ -296,6 +296,36 @@
                };
        };
 
+       pinmux@1b00103c {
+               compatible = "pinctrl-single";
+               reg = <0x1b00103c 0x4>;
+
+               pinctrl-single,bit-per-mux;
+               pinctrl-single,register-width = <32>;
+               pinctrl-single,function-mask = <0x1>;
+               #pinctrl-cells = <2>;
+
+               /* 31.25 MHz SPI master clock */
+               pinmux_spi0_31mhz: spi0-31mhz {
+                       pinctrl-single,bits = <0x0 0x1800 0x3800>;
+               };
+
+               /* Enable GPIO 8, 9, 10 */
+               pinmux_disable_spi0: disable-spi0 {
+                       pinctrl-single,bits = <0x0 0x0 0x400>;
+               };
+
+               /* Enable GPIO 12 */
+               pinmux_disable_spi0_cs1: disable-spi-cs1 {
+                       pinctrl-single,bits = <0x0 0x0 0x200>;
+               };
+
+               /* Enable GPIO 11 */
+               pinmux_disable_spi0_cs0: disable-spi-cs0 {
+                       pinctrl-single,bits = <0x0 0x0 0x100>;
+               };
+       };
+
        pinmux@1b001358 {
                compatible = "pinctrl-single";
                reg = <0x1b001358 0x4>;

diff --git a/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl838x/mach-rtl83xx.h b/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl838x/mach-rtl83xx.h
index 720dc4276f0d934316101fe2746c4911b2c9246b..364b66b73a2004863230b44c50b70259c9adab7b 100644 (file)
--- a/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl838x/mach-rtl83xx.h
+++ b/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl838x/mach-rtl83xx.h
@@ -105,9 +105,6 @@
 #define RTL9300_FAMILY_ID              (0x9300)
 #define RTL9310_FAMILY_ID              (0x9310)
 
-/* SPI Support */
-#define RTL931X_SPI_CTRL0              (0x103C)
-
 /* Basic SoC Features */
 #define RTL838X_CPU_PORT               28
 #define RTL839X_CPU_PORT               52

diff --git a/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c b/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c
index 4b9ea3be683652d6618050490d1827851952d545..99422d0d4cacb3a79f7e1d6ac5cda4f46dee3125 100644 (file)
--- a/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c
+++ b/target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c
@@ -1519,9 +1519,6 @@ static int rtl931x_chip_init(struct rtl838x_eth_priv *priv)
        /* Enable ESD auto recovery */
        sw_w32(0x1, RTL931X_MDX_CTRL_RSVD);
 
-       /* Init SPI, is this for thermal control or what? */
-       sw_w32_mask(0x7 << 11, 0x2 << 11, RTL931X_SPI_CTRL0);
-
        return 0;
 }