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, 154 insertions, 1 deletions

diff --git a/drivers/mfd/rts5249.c b/drivers/mfd/rts5249.c
index 40f8bb14fc59..7fcf37ba922c 100644
--- a/drivers/mfd/rts5249.c
+++ b/drivers/mfd/rts5249.c
@@ -103,8 +103,64 @@ static void rtsx_base_force_power_down(struct rtsx_pcr *pcr, u8 pm_state)
 	rtsx_pci_write_register(pcr, FPDCTL, 0x03, 0x03);
 }
 
+static void rts5249_init_from_cfg(struct rtsx_pcr *pcr)
+{
+	struct rtsx_cr_option *option = &(pcr->option);
+	u32 lval;
+
+	if (CHK_PCI_PID(pcr, PID_524A))
+		rtsx_pci_read_config_dword(pcr,
+			PCR_ASPM_SETTING_REG1, &lval);
+	else
+		rtsx_pci_read_config_dword(pcr,
+			PCR_ASPM_SETTING_REG2, &lval);
+
+	if (lval & ASPM_L1_1_EN_MASK)
+		rtsx_set_dev_flag(pcr, ASPM_L1_1_EN);
+
+	if (lval & ASPM_L1_2_EN_MASK)
+		rtsx_set_dev_flag(pcr, ASPM_L1_2_EN);
+
+	if (lval & PM_L1_1_EN_MASK)
+		rtsx_set_dev_flag(pcr, PM_L1_1_EN);
+
+	if (lval & PM_L1_2_EN_MASK)
+		rtsx_set_dev_flag(pcr, PM_L1_2_EN);
+
+	if (option->ltr_en) {
+		u16 val;
+
+		pcie_capability_read_word(pcr->pci, PCI_EXP_DEVCTL2, &val);
+		if (val & PCI_EXP_DEVCTL2_LTR_EN) {
+			option->ltr_enabled = true;
+			option->ltr_active = true;
+			rtsx_set_ltr_latency(pcr, option->ltr_active_latency);
+		} else {
+			option->ltr_enabled = false;
+		}
+	}
+}
+
+static int rts5249_init_from_hw(struct rtsx_pcr *pcr)
+{
+	struct rtsx_cr_option *option = &(pcr->option);
+
+	if (rtsx_check_dev_flag(pcr, ASPM_L1_1_EN | ASPM_L1_2_EN
+				| PM_L1_1_EN | PM_L1_2_EN))
+		option->force_clkreq_0 = false;
+	else
+		option->force_clkreq_0 = true;
+
+	return 0;
+}
+
 static int rts5249_extra_init_hw(struct rtsx_pcr *pcr)
 {
+	struct rtsx_cr_option *option = &(pcr->option);
+
+	rts5249_init_from_cfg(pcr);
+	rts5249_init_from_hw(pcr);
+
 	rtsx_pci_init_cmd(pcr);
 
 	/* Rest L1SUB Config */
@@ -125,7 +181,18 @@ static int rts5249_extra_init_hw(struct rtsx_pcr *pcr)
 	else
 		rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PETXCFG, 0xB0, 0x80);
 
-	return rtsx_pci_send_cmd(pcr, 100);
+	/*
+	 * If u_force_clkreq_0 is enabled, CLKREQ# PIN will be forced
+	 * to drive low, and we forcibly request clock.
+	 */
+	if (option->force_clkreq_0)
+		rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PETXCFG,
+			FORCE_CLKREQ_DELINK_MASK, FORCE_CLKREQ_LOW);
+	else
+		rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, PETXCFG,
+			FORCE_CLKREQ_DELINK_MASK, FORCE_CLKREQ_HIGH);
+
+	return rtsx_pci_send_cmd(pcr, CMD_TIMEOUT_DEF);
 }
 
 static int rts5249_optimize_phy(struct rtsx_pcr *pcr)
@@ -285,6 +352,31 @@ static int rtsx_base_switch_output_voltage(struct rtsx_pcr *pcr, u8 voltage)
 	return rtsx_pci_send_cmd(pcr, 100);
 }
 
+static void rts5249_set_aspm(struct rtsx_pcr *pcr, bool enable)
+{
+	struct rtsx_cr_option *option = &pcr->option;
+	u8 val = 0;
+
+	if (pcr->aspm_enabled == enable)
+		return;
+
+	if (option->dev_aspm_mode == DEV_ASPM_DYNAMIC) {
+		if (enable)
+			val = pcr->aspm_en;
+		rtsx_pci_update_cfg_byte(pcr,
+			pcr->pcie_cap + PCI_EXP_LNKCTL,
+			ASPM_MASK_NEG, val);
+	} else if (option->dev_aspm_mode == DEV_ASPM_BACKDOOR) {
+		u8 mask = FORCE_ASPM_VAL_MASK | FORCE_ASPM_CTL0;
+
+		if (!enable)
+			val = FORCE_ASPM_CTL0;
+		rtsx_pci_write_register(pcr, ASPM_FORCE_CTL, mask, val);
+	}
+
+	pcr->aspm_enabled = enable;
+}
+
 static const struct pcr_ops rts5249_pcr_ops = {
 	.fetch_vendor_settings = rtsx_base_fetch_vendor_settings,
 	.extra_init_hw = rts5249_extra_init_hw,
@@ -297,6 +389,7 @@ static const struct pcr_ops rts5249_pcr_ops = {
 	.card_power_off = rtsx_base_card_power_off,
 	.switch_output_voltage = rtsx_base_switch_output_voltage,
 	.force_power_down = rtsx_base_force_power_down,
+	.set_aspm = rts5249_set_aspm,
 };
 
 /* SD Pull Control Enable:
@@ -353,6 +446,8 @@ static const u32 rts5249_ms_pull_ctl_disable_tbl[] = {
 
 void rts5249_init_params(struct rtsx_pcr *pcr)
 {
+	struct rtsx_cr_option *option = &(pcr->option);
+
 	pcr->extra_caps = EXTRA_CAPS_SD_SDR50 | EXTRA_CAPS_SD_SDR104;
 	pcr->num_slots = 2;
 	pcr->ops = &rts5249_pcr_ops;
@@ -372,6 +467,20 @@ void rts5249_init_params(struct rtsx_pcr *pcr)
 	pcr->ms_pull_ctl_disable_tbl = rts5249_ms_pull_ctl_disable_tbl;
 
 	pcr->reg_pm_ctrl3 = PM_CTRL3;
+
+	option->dev_flags = (LTR_L1SS_PWR_GATE_CHECK_CARD_EN
+				| LTR_L1SS_PWR_GATE_EN);
+	option->ltr_en = true;
+
+	/* Init latency of active, idle, L1OFF to 60us, 300us, 3ms */
+	option->ltr_active_latency = LTR_ACTIVE_LATENCY_DEF;
+	option->ltr_idle_latency = LTR_IDLE_LATENCY_DEF;
+	option->ltr_l1off_latency = LTR_L1OFF_LATENCY_DEF;
+	option->dev_aspm_mode = DEV_ASPM_DYNAMIC;
+	option->l1_snooze_delay = L1_SNOOZE_DELAY_DEF;
+	option->ltr_l1off_sspwrgate = LTR_L1OFF_SSPWRGATE_5249_DEF;
+	option->ltr_l1off_snooze_sspwrgate =
+		LTR_L1OFF_SNOOZE_SSPWRGATE_5249_DEF;
 }
 
 static int rts524a_write_phy(struct rtsx_pcr *pcr, u8 addr, u16 val)
@@ -459,6 +568,40 @@ static int rts524a_extra_init_hw(struct rtsx_pcr *pcr)
 	return 0;
 }
 
+static void rts5250_set_l1off_cfg_sub_d0(struct rtsx_pcr *pcr, int active)
+{
+	struct rtsx_cr_option *option = &(pcr->option);
+
+	u32 interrupt = rtsx_pci_readl(pcr, RTSX_BIPR);
+	int card_exist = (interrupt & SD_EXIST) | (interrupt & MS_EXIST);
+	int aspm_L1_1, aspm_L1_2;
+	u8 val = 0;
+
+	aspm_L1_1 = rtsx_check_dev_flag(pcr, ASPM_L1_1_EN);
+	aspm_L1_2 = rtsx_check_dev_flag(pcr, ASPM_L1_2_EN);
+
+	if (active) {
+		/* Run, latency: 60us */
+		if (aspm_L1_1)
+			val = option->ltr_l1off_snooze_sspwrgate;
+	} else {
+		/* L1off, latency: 300us */
+		if (aspm_L1_2)
+			val = option->ltr_l1off_sspwrgate;
+	}
+
+	if (aspm_L1_1 || aspm_L1_2) {
+		if (rtsx_check_dev_flag(pcr,
+					LTR_L1SS_PWR_GATE_CHECK_CARD_EN)) {
+			if (card_exist)
+				val &= ~L1OFF_MBIAS2_EN_5250;
+			else
+				val |= L1OFF_MBIAS2_EN_5250;
+		}
+	}
+	rtsx_set_l1off_sub(pcr, val);
+}
+
 static const struct pcr_ops rts524a_pcr_ops = {
 	.write_phy = rts524a_write_phy,
 	.read_phy = rts524a_read_phy,
@@ -473,11 +616,16 @@ static const struct pcr_ops rts524a_pcr_ops = {
 	.card_power_off = rtsx_base_card_power_off,
 	.switch_output_voltage = rtsx_base_switch_output_voltage,
 	.force_power_down = rtsx_base_force_power_down,
+	.set_l1off_cfg_sub_d0 = rts5250_set_l1off_cfg_sub_d0,
+	.set_aspm = rts5249_set_aspm,
 };
 
 void rts524a_init_params(struct rtsx_pcr *pcr)
 {
 	rts5249_init_params(pcr);
+	pcr->option.ltr_l1off_sspwrgate = LTR_L1OFF_SSPWRGATE_5250_DEF;
+	pcr->option.ltr_l1off_snooze_sspwrgate =
+		LTR_L1OFF_SNOOZE_SSPWRGATE_5250_DEF;
 
 	pcr->reg_pm_ctrl3 = RTS524A_PM_CTRL3;
 	pcr->ops = &rts524a_pcr_ops;
@@ -576,11 +724,16 @@ static const struct pcr_ops rts525a_pcr_ops = {
 	.card_power_off = rtsx_base_card_power_off,
 	.switch_output_voltage = rts525a_switch_output_voltage,
 	.force_power_down = rtsx_base_force_power_down,
+	.set_l1off_cfg_sub_d0 = rts5250_set_l1off_cfg_sub_d0,
+	.set_aspm = rts5249_set_aspm,
 };
 
 void rts525a_init_params(struct rtsx_pcr *pcr)
 {
 	rts5249_init_params(pcr);
+	pcr->option.ltr_l1off_sspwrgate = LTR_L1OFF_SSPWRGATE_5250_DEF;
+	pcr->option.ltr_l1off_snooze_sspwrgate =
+		LTR_L1OFF_SNOOZE_SSPWRGATE_5250_DEF;
 
 	pcr->reg_pm_ctrl3 = RTS524A_PM_CTRL3;
 	pcr->ops = &rts525a_pcr_ops;