6.6-stable review patch. If anyone has any objections, please let me know.
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From: Théo Lebrun theo.lebrun@bootlin.com
[ Upstream commit c538d40f365b5b6d7433d371710f58e8b266fb19 ]
Add suspend and resume support. Only the Root Complex mode is supported.
During the suspend stage PERST# is asserted, then deasserted during the resume stage.
Link: https://lore.kernel.org/linux-pci/20240102-j7200-pcie-s2r-v7-7-a2f9156da6c3@... Signed-off-by: Théo Lebrun theo.lebrun@bootlin.com Signed-off-by: Thomas Richard thomas.richard@bootlin.com [kwilczynski: commit log, update references to the PCI SIG specification] Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org Reviewed-by: Siddharth Vadapalli s-vadapalli@ti.com Stable-dep-of: 22a9120479a4 ("PCI: j721e: Deassert PERST# after a delay of PCIE_T_PVPERL_MS milliseconds") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b83ae35a210fe..212b11c3145d8 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 @@ -512,12 +516,12 @@ 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. + * The "Power Sequencing and Reset Signal Timings" table of the + * PCI Express Card Electromechanical Specification, Revision + * 5.1, Section 2.9.2, Symbol "T_PERST-CLK", 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. */ if (gpiod) { fsleep(PCIE_T_PERST_CLK_US); @@ -569,6 +573,87 @@ 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; + + /* + * The "Power Sequencing and Reset Signal Timings" table of the + * PCI Express Card Electromechanical Specification, Revision + * 5.1, Section 2.9.2, Symbol "T_PERST-CLK", 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. + */ + 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, @@ -576,6 +661,7 @@ 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);