mfd: rts5249: Add support for RTS5250S power saving

Enable power saving for RTS5250S as following steps:
1.Set 0xFE58 to enable clock power management.
2.Check cfg space whether support L1SS or not.
3.If support L1SS, set 0xFF03 to free clkreq.
4.When entering idle status, enable aspm
  and set parameters for L1SS and LTR.
5.Wnen entering run status, disable aspm
  and set parameters for L1SS and LTR.
If entering L1SS mode successfully,
electric current will be below 2mA.

Signed-off-by: Rui Feng <rui_feng@realsil.com.cn>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 137 insertions, 5 deletions

diff --git a/drivers/mfd/rtsx_pcr.c b/drivers/mfd/rtsx_pcr.c
index 3cf69e5c5703..590fb9aad77d 100644
--- a/drivers/mfd/rtsx_pcr.c
+++ b/drivers/mfd/rtsx_pcr.c
@@ -79,6 +79,96 @@ static inline void rtsx_pci_disable_aspm(struct rtsx_pcr *pcr)
 		0xFC, 0);
 }
 
+int rtsx_comm_set_ltr_latency(struct rtsx_pcr *pcr, u32 latency)
+{
+	rtsx_pci_write_register(pcr, MSGTXDATA0,
+				MASK_8_BIT_DEF, (u8) (latency & 0xFF));
+	rtsx_pci_write_register(pcr, MSGTXDATA1,
+				MASK_8_BIT_DEF, (u8)((latency >> 8) & 0xFF));
+	rtsx_pci_write_register(pcr, MSGTXDATA2,
+				MASK_8_BIT_DEF, (u8)((latency >> 16) & 0xFF));
+	rtsx_pci_write_register(pcr, MSGTXDATA3,
+				MASK_8_BIT_DEF, (u8)((latency >> 24) & 0xFF));
+	rtsx_pci_write_register(pcr, LTR_CTL, LTR_TX_EN_MASK |
+		LTR_LATENCY_MODE_MASK, LTR_TX_EN_1 | LTR_LATENCY_MODE_SW);
+
+	return 0;
+}
+
+int rtsx_set_ltr_latency(struct rtsx_pcr *pcr, u32 latency)
+{
+	if (pcr->ops->set_ltr_latency)
+		return pcr->ops->set_ltr_latency(pcr, latency);
+	else
+		return rtsx_comm_set_ltr_latency(pcr, latency);
+}
+
+static void rtsx_comm_set_aspm(struct rtsx_pcr *pcr, bool enable)
+{
+	struct rtsx_cr_option *option = &pcr->option;
+
+	if (pcr->aspm_enabled == enable)
+		return;
+
+	if (option->dev_aspm_mode == DEV_ASPM_DYNAMIC) {
+		if (enable)
+			rtsx_pci_enable_aspm(pcr);
+		else
+			rtsx_pci_disable_aspm(pcr);
+	} else if (option->dev_aspm_mode == DEV_ASPM_BACKDOOR) {
+		u8 mask = FORCE_ASPM_VAL_MASK;
+		u8 val = 0;
+
+		if (enable)
+			val = pcr->aspm_en;
+		rtsx_pci_write_register(pcr, ASPM_FORCE_CTL,  mask, val);
+	}
+
+	pcr->aspm_enabled = enable;
+}
+
+static void rtsx_disable_aspm(struct rtsx_pcr *pcr)
+{
+	if (pcr->ops->set_aspm)
+		pcr->ops->set_aspm(pcr, false);
+	else
+		rtsx_comm_set_aspm(pcr, false);
+}
+
+int rtsx_set_l1off_sub(struct rtsx_pcr *pcr, u8 val)
+{
+	rtsx_pci_write_register(pcr, L1SUB_CONFIG3, 0xFF, val);
+
+	return 0;
+}
+
+void rtsx_set_l1off_sub_cfg_d0(struct rtsx_pcr *pcr, int active)
+{
+	if (pcr->ops->set_l1off_cfg_sub_d0)
+		pcr->ops->set_l1off_cfg_sub_d0(pcr, active);
+}
+
+static void rtsx_comm_pm_full_on(struct rtsx_pcr *pcr)
+{
+	struct rtsx_cr_option *option = &pcr->option;
+
+	rtsx_disable_aspm(pcr);
+
+	if (option->ltr_enabled)
+		rtsx_set_ltr_latency(pcr, option->ltr_active_latency);
+
+	if (rtsx_check_dev_flag(pcr, LTR_L1SS_PWR_GATE_EN))
+		rtsx_set_l1off_sub_cfg_d0(pcr, 1);
+}
+
+void rtsx_pm_full_on(struct rtsx_pcr *pcr)
+{
+	if (pcr->ops->full_on)
+		pcr->ops->full_on(pcr);
+	else
+		rtsx_comm_pm_full_on(pcr);
+}
+
 void rtsx_pci_start_run(struct rtsx_pcr *pcr)
 {
 	/* If pci device removed, don't queue idle work any more */
@@ -89,9 +179,7 @@ void rtsx_pci_start_run(struct rtsx_pcr *pcr)
 		pcr->state = PDEV_STAT_RUN;
 		if (pcr->ops->enable_auto_blink)
 			pcr->ops->enable_auto_blink(pcr);
-
-		if (pcr->aspm_en)
-			rtsx_pci_disable_aspm(pcr);
+		rtsx_pm_full_on(pcr);
 	}
 
 	mod_delayed_work(system_wq, &pcr->idle_work, msecs_to_jiffies(200));
@@ -958,6 +1046,41 @@ static int rtsx_pci_acquire_irq(struct rtsx_pcr *pcr)
 	return 0;
 }
 
+static void rtsx_enable_aspm(struct rtsx_pcr *pcr)
+{
+	if (pcr->ops->set_aspm)
+		pcr->ops->set_aspm(pcr, true);
+	else
+		rtsx_comm_set_aspm(pcr, true);
+}
+
+static void rtsx_comm_pm_power_saving(struct rtsx_pcr *pcr)
+{
+	struct rtsx_cr_option *option = &pcr->option;
+
+	if (option->ltr_enabled) {
+		u32 latency = option->ltr_l1off_latency;
+
+		if (rtsx_check_dev_flag(pcr, L1_SNOOZE_TEST_EN))
+			mdelay(option->l1_snooze_delay);
+
+		rtsx_set_ltr_latency(pcr, latency);
+	}
+
+	if (rtsx_check_dev_flag(pcr, LTR_L1SS_PWR_GATE_EN))
+		rtsx_set_l1off_sub_cfg_d0(pcr, 0);
+
+	rtsx_enable_aspm(pcr);
+}
+
+void rtsx_pm_power_saving(struct rtsx_pcr *pcr)
+{
+	if (pcr->ops->power_saving)
+		pcr->ops->power_saving(pcr);
+	else
+		rtsx_comm_pm_power_saving(pcr);
+}
+
 static void rtsx_pci_idle_work(struct work_struct *work)
 {
 	struct delayed_work *dwork = to_delayed_work(work);
@@ -974,8 +1097,7 @@ static void rtsx_pci_idle_work(struct work_struct *work)
 	if (pcr->ops->turn_off_led)
 		pcr->ops->turn_off_led(pcr);
 
-	if (pcr->aspm_en)
-		rtsx_pci_enable_aspm(pcr);
+	rtsx_pm_power_saving(pcr);
 
 	mutex_unlock(&pcr->pcr_mutex);
 }
@@ -1063,6 +1185,16 @@ static int rtsx_pci_init_hw(struct rtsx_pcr *pcr)
 	if (err < 0)
 		return err;
 
+	switch (PCI_PID(pcr)) {
+	case PID_5250:
+	case PID_524A:
+	case PID_525A:
+		rtsx_pci_write_register(pcr, PM_CLK_FORCE_CTL, 1, 1);
+		break;
+	default:
+		break;
+	}
+
 	/* Enable clk_request_n to enable clock power management */
 	rtsx_pci_write_config_byte(pcr, pcr->pcie_cap + PCI_EXP_LNKCTL + 1, 1);
 	/* Enter L1 when host tx idle */