pmdomain: mediatek: Add support for modem power sequences

Add support for the modem power domains by adding its specific
power sequence in functions scpsys_modem_pwrseq_{on,off}() and
call them if the flag MTK_SCPD_MODEM_PWRSEQ is present.

While at it, since some SoC models need to skip setting/clearing
the PWR_RST_B_BIT, also add a MTK_SCPD_SKIP_RESET_B flag for that.

Reviewed-by: Nícolas F. R. A. Prado <[e-mail]>
Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/pmdomain/mediatek/mtk-pm-domains.c

···
 	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_BIT);
 }
 
+static int scpsys_modem_pwrseq_on(struct scpsys_domain *pd)
+{
+	struct scpsys *scpsys = pd->scpsys;
+	bool tmp;
+	int ret;
+
+	if (!MTK_SCPD_CAPS(pd, MTK_SCPD_SKIP_RESET_B))
+		regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
+
+	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_BIT);
+
+	/* wait until PWR_ACK = 1 */
+	ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp, MTK_POLL_DELAY_US,
+				 MTK_POLL_TIMEOUT);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void scpsys_modem_pwrseq_off(struct scpsys_domain *pd)
+{
+	struct scpsys *scpsys = pd->scpsys;
+
+	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_BIT);
+
+	if (!MTK_SCPD_CAPS(pd, MTK_SCPD_SKIP_RESET_B))
+		regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
+}
+
 static int scpsys_power_on(struct generic_pm_domain *genpd)
 {
 	struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
···
 		regmap_clear_bits(scpsys->base, pd->data->ext_buck_iso_offs,
 				  pd->data->ext_buck_iso_mask);
 
-	ret = scpsys_ctl_pwrseq_on(pd);
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_MODEM_PWRSEQ))
+		ret = scpsys_modem_pwrseq_on(pd);
+	else
+		ret = scpsys_ctl_pwrseq_on(pd);
+
 	if (ret)
 		goto err_pwr_ack;
 
···
 
 	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
 
-	scpsys_ctl_pwrseq_off(pd);
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_MODEM_PWRSEQ))
+		scpsys_modem_pwrseq_off(pd);
+	else
+		scpsys_ctl_pwrseq_off(pd);
 
 	/* wait until PWR_ACK = 0 */
 	ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, !tmp, MTK_POLL_DELAY_US,

drivers/pmdomain/mediatek/mtk-pm-domains.h

···
 #define MTK_SCPD_HAS_INFRA_NAO		BIT(7)
 #define MTK_SCPD_STRICT_BUS_PROTECTION	BIT(8)
 #define MTK_SCPD_SRAM_PDN_INVERTED	BIT(9)
+#define MTK_SCPD_MODEM_PWRSEQ		BIT(10)
+#define MTK_SCPD_SKIP_RESET_B		BIT(11)
 #define MTK_SCPD_CAPS(_scpd, _x)	((_scpd)->data->caps & (_x))
 
 #define SPM_VDE_PWR_CON			0x0210