MLK-10017 PCI: save power when pcie is not used

In order to save power consumption, do the
following actions when pcie is not used.
- turn off clocks on imx6q/dl.
- turn off clocks and power on imx6sx

Signed-off-by: Richard Zhu <Richard.Zhu@freescale.com>
(cherry picked from commit e9796dfbae2a8b732022a6c96b3d7803099a70b5)

3 files changed, 33 insertions, 7 deletions

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 1d0c96120e9a..1d88f4201bef 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -422,7 +422,7 @@ static irqreturn_t imx_pcie_msi_irq_handler(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
-static void imx6_pcie_host_init(struct pcie_port *pp)
+static int imx6_pcie_host_init(struct pcie_port *pp)
 {
 	int count = 0;
 	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
@@ -459,14 +459,37 @@ static void imx6_pcie_host_init(struct pcie_port *pp)
 				"DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
 				readl(pp->dbi_base + PCIE_PHY_DEBUG_R0),
 				readl(pp->dbi_base + PCIE_PHY_DEBUG_R1));
-			return;
+			clk_disable_unprepare(imx6_pcie->pcie_axi);
+			if (!IS_ENABLED(CONFIG_EP_MODE_IN_EP_RC_SYS)
+				&& !IS_ENABLED(CONFIG_RC_MODE_IN_EP_RC_SYS))
+				clk_disable_unprepare(imx6_pcie->lvds_gate);
+			clk_disable_unprepare(imx6_pcie->pcie_ref_125m);
+			if (is_imx6sx_pcie(imx6_pcie)) {
+				/* Disable clks and power down PCIe PHY */
+				clk_disable_unprepare(imx6_pcie->dis_axi);
+				release_bus_freq(BUS_FREQ_HIGH);
+
+				/* Put PCIe PHY to be isolation */
+				regmap_update_bits(imx6_pcie->iomuxc_gpr,
+						IOMUXC_GPR0, BIT(6), 1 << 6);
+
+				/*
+				 * Power down PCIe PHY.
+				 */
+				regulator_disable(imx6_pcie->pcie_phy_reg);
+				regulator_disable(imx6_pcie->pcie_reg);
+			} else {
+				clk_disable_unprepare(imx6_pcie->sata_ref_100m);
+				release_bus_freq(BUS_FREQ_HIGH);
+			}
+			return -ENODEV;
 		}
 	}
 
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		dw_pcie_msi_init(pp);
 
-	return;
+	return 0;
 }
 
 static int imx6_pcie_link_up(struct pcie_port *pp)
diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 882c713145bb..a320e5a3d4f5 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -408,7 +408,7 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
 	struct of_pci_range range;
 	struct of_pci_range_parser parser;
 	u32 val;
-	int i;
+	int i, ret = 0;
 
 	if (of_pci_range_parser_init(&parser, np)) {
 		dev_err(pp->dev, "missing ranges property\n");
@@ -489,8 +489,11 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
 			irq_create_mapping(pp->irq_domain, i);
 	}
 
-	if (pp->ops->host_init)
-		pp->ops->host_init(pp);
+	if (pp->ops->host_init) {
+		ret = pp->ops->host_init(pp);
+		if (ret < 0)
+			return -ENODEV;
+	}
 
 	dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);
 
diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h
index c3caa81ad85f..6396ecdb198f 100644
--- a/drivers/pci/host/pcie-designware.h
+++ b/drivers/pci/host/pcie-designware.h
@@ -107,7 +107,7 @@ struct pcie_host_ops {
 	int (*rd_own_conf)(struct pcie_port *pp, int where, int size, u32 *val);
 	int (*wr_own_conf)(struct pcie_port *pp, int where, int size, u32 val);
 	int (*link_up)(struct pcie_port *pp);
-	void (*host_init)(struct pcie_port *pp);
+	int (*host_init)(struct pcie_port *pp);
 	void (*msi_set_irq)(struct pcie_port *pp, int irq);
 	void (*msi_clear_irq)(struct pcie_port *pp, int irq);
 	u32 (*get_msi_data)(struct pcie_port *pp);