arm64: dts: ti: k3-am625-beagleplay: Use mmc-pwrseq for wl18xx enable

BeaglePlay SBC[1] has Texas Instrument's WL18xx WiFi chipset[2].

Currently, WLAN_EN is configured as regulator and regulator-always-on.
However, the timing and wlan_en sequencing is not correctly modelled.

This causes the sdio access to fail during runtime-pm power operations
saving or during system suspend/resume/hibernation/freeze operations.
This is because the WLAN_EN line is not deasserted to low '0' to power
down the WiFi. So during restore, the WiFi driver tries to load the FW
without following correct power sequence. WLAN_EN => '1'/assert (high)
to power-up the chipset.

Use mmc-pwrseq-simple to drive TI's WiFi (WL18xx) chipset enable
'WLAN_EN'. mmc-pwrseq-simple provides power sequence flexibility with
support for post power-on and power-off delays.

Typical log signature that indicates this bug is:
wl1271_sdio mmc2:0001:2: sdio write failed (-110)

Followed by possibly a kernel warning (depending on firmware present):
WARNING: CPU: 1 PID: 45 at drivers/net/wireless/ti/wlcore/sdio.c:123 wl12xx_sdio_raw_write+0xe4/0x168 [wlcore_sdio]

[1] https://www.beagleboard.org/boards/beagleplay
[2] https://www.ti.com/lit/ds/symlink/wl1807mod.pdf

Fixes: f5a731f0787f ("arm64: dts: ti: Add k3-am625-beagleplay")
Suggested-by: Shengyu Qu <wiagn233@outlook.com>
Signed-off-by: Sukrut Bellary <sukrut.bellary@linux.com>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Link: https://lore.kernel.org/r/20240325143511.2144768-1-nm@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>

diff --git a/arch/arm64/boot/dts/ti/k3-am625-beagleplay.dts b/arch/arm64/boot/dts/ti/k3-am625-beagleplay.dts
index a34e0df2ab8646206b26c19f529629f9dfedf226..84977c1cc85dfbf563b816be257480510371e898 100644 (file)
--- a/arch/arm64/boot/dts/ti/k3-am625-beagleplay.dts
+++ b/arch/arm64/boot/dts/ti/k3-am625-beagleplay.dts
@@ -82,6 +82,17 @@
                };
        };
 
+       sdio_pwrseq: sdio-pwrseq {
+               compatible = "mmc-pwrseq-simple";
+               pinctrl-names = "default";
+               pinctrl-0 = <&wifi_en_pins_default>;
+               /* Internal power on time(Figure 8-3) * 2 */
+               post-power-on-delay-ms = <10>;
+               /* Re-enable time(Figure 8-2) + 20uS */
+               power-off-delay-us = <80>;
+               reset-gpios = <&main_gpio0 38 GPIO_ACTIVE_LOW>;
+       };
+
        vsys_5v0: regulator-1 {
                bootph-all;
                compatible = "regulator-fixed";
@@ -104,20 +115,6 @@
                regulator-boot-on;
        };
 
-       wlan_en: regulator-3 {
-               /* OUTPUT of SN74AVC2T244DQMR */
-               compatible = "regulator-fixed";
-               regulator-name = "wlan_en";
-               regulator-min-microvolt = <1800000>;
-               regulator-max-microvolt = <1800000>;
-               enable-active-high;
-               regulator-always-on;
-               vin-supply = <&vdd_3v3>;
-               gpio = <&main_gpio0 38 GPIO_ACTIVE_HIGH>;
-               pinctrl-names = "default";
-               pinctrl-0 = <&wifi_en_pins_default>;
-       };
-
        vdd_3v3_sd: regulator-4 {
                /* output of TPS22918DBVR-U21 */
                bootph-all;
@@ -839,13 +836,13 @@
 };
 
 &sdhci2 {
-       vmmc-supply = <&wlan_en>;
        pinctrl-names = "default";
        pinctrl-0 = <&wifi_pins_default>, <&wifi_32k_clk>;
        non-removable;
        ti,fails-without-test-cd;
        cap-power-off-card;
        keep-power-in-suspend;
+       mmc-pwrseq = <&sdio_pwrseq>;
        assigned-clocks = <&k3_clks 157 158>;
        assigned-clock-parents = <&k3_clks 157 160>;
        #address-cells = <1>;