From: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
Add suspend and resume support. Only the rc mode is supported.
During the suspend stage PERST# is asserted, then deasserted during the
resume stage.
Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@xxxxxx>
Signed-off-by: Thomas Richard <thomas.richard@xxxxxxxxxxx>
---
drivers/pci/controller/cadence/pci-j721e.c | 98 ++++++++++++++++++++++++++++--
1 file changed, 92 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
index 967a5bf38e26..96316a79ab8a 100644
--- a/drivers/pci/controller/cadence/pci-j721e.c
+++ b/drivers/pci/controller/cadence/pci-j721e.c
@@ -7,6 +7,8 @@
*/
#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/container_of.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/io.h>
@@ -22,6 +24,8 @@
#include "../../pci.h"
#include "pcie-cadence.h"
+#define cdns_pcie_to_rc(p) container_of(p, struct cdns_pcie_rc, pcie)
+
#define ENABLE_REG_SYS_2 0x108
#define STATUS_REG_SYS_2 0x508
#define STATUS_CLR_REG_SYS_2 0x708
@@ -531,12 +535,12 @@ static int j721e_pcie_probe(struct platform_device *pdev)
pcie->refclk = clk;
/*
- * "Power Sequencing and Reset Signal Timings" table in
- * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0
- * indicates PERST# should be deasserted after minimum of 100us
- * once REFCLK is stable. The REFCLK to the connector in RC
- * mode is selected while enabling the PHY. So deassert PERST#
- * after 100 us.
+ * "Power Sequencing and Reset Signal Timings" table (section
+ * 2.9.2) in PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION,
+ * REV. 5.1 indicates PERST# should be deasserted after minimum
+ * of 100us once REFCLK is stable (symbol T_PERST-CLK).
+ * The REFCLK to the connector in RC mode is selected while
+ * enabling the PHY. So deassert PERST# after 100 us.
*/
if (gpiod) {
fsleep(PCIE_T_PERST_CLK_US);
@@ -588,6 +592,87 @@ static void j721e_pcie_remove(struct platform_device *pdev)
pm_runtime_disable(dev);
}
+static int j721e_pcie_suspend_noirq(struct device *dev)
+{
+ struct j721e_pcie *pcie = dev_get_drvdata(dev);
+
+ if (pcie->mode == PCI_MODE_RC) {
+ gpiod_set_value_cansleep(pcie->reset_gpio, 0);
+ clk_disable_unprepare(pcie->refclk);
+ }
+
+ cdns_pcie_disable_phy(pcie->cdns_pcie);
+
+ return 0;
+}
+
+static int j721e_pcie_resume_noirq(struct device *dev)
+{
+ struct j721e_pcie *pcie = dev_get_drvdata(dev);
+ struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
+ int ret;
+
+ ret = j721e_pcie_ctrl_init(pcie);
+ if (ret < 0)
+ return ret;
+
+ j721e_pcie_config_link_irq(pcie);
+
+ /*
+ * This is not called explicitly in the probe, it is called by
+ * cdns_pcie_init_phy().
+ */
+ ret = cdns_pcie_enable_phy(pcie->cdns_pcie);
+ if (ret < 0)
+ return ret;
+
+ if (pcie->mode == PCI_MODE_RC) {
+ struct cdns_pcie_rc *rc = cdns_pcie_to_rc(cdns_pcie);
+
+ ret = clk_prepare_enable(pcie->refclk);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * "Power Sequencing and Reset Signal Timings" table (section
+ * 2.9.2) in PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION,
+ * REV. 5.1 indicates PERST# should be deasserted after minimum
+ * of 100us once REFCLK is stable (symbol T_PERST-CLK).
+ * The REFCLK to the connector in RC mode is selected while
+ * enabling the PHY. So deassert PERST# after 100 us.
+ */
+ if (pcie->reset_gpio) {
+ fsleep(PCIE_T_PERST_CLK_US);
+ gpiod_set_value_cansleep(pcie->reset_gpio, 1);
+ }
+
+ ret = cdns_pcie_host_link_setup(rc);
+ if (ret < 0) {
+ clk_disable_unprepare(pcie->refclk);
+ return ret;
+ }
+
+ /*
+ * Reset internal status of BARs to force reinitialization in
+ * cdns_pcie_host_init().
+ */
+ for (enum cdns_pcie_rp_bar bar = RP_BAR0; bar <= RP_NO_BAR; bar++)
+ rc->avail_ib_bar[bar] = true;
+
+ ret = cdns_pcie_host_init(rc);
+ if (ret) {
+ clk_disable_unprepare(pcie->refclk);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static DEFINE_NOIRQ_DEV_PM_OPS(j721e_pcie_pm_ops,
+ j721e_pcie_suspend_noirq,
+ j721e_pcie_resume_noirq);
+
static struct platform_driver j721e_pcie_driver = {
.probe = j721e_pcie_probe,
.remove_new = j721e_pcie_remove,
@@ -595,6 +680,7 @@ static struct platform_driver j721e_pcie_driver = {
.name = "j721e-pcie",
.of_match_table = of_j721e_pcie_match,
.suppress_bind_attrs = true,
+ .pm = pm_sleep_ptr(&j721e_pcie_pm_ops),
},
};
builtin_platform_driver(j721e_pcie_driver);
--
2.39.2
