diff options
author | Hou Zhiqiang <Zhiqiang.Hou@nxp.com> | 2023-08-21 21:48:15 +0300 |
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committer | Lorenzo Pieralisi <lpieralisi@kernel.org> | 2023-08-24 12:49:38 +0300 |
commit | 9fda4d09905db9ecae17ad741924a7530aa3c96e (patch) | |
tree | 81418004740d5c7e92792f3b4907ff8863abad02 | |
parent | 4774faf854f53461fd22daa73f3881fe11b6b755 (diff) | |
download | linux-9fda4d09905db9ecae17ad741924a7530aa3c96e.tar.xz |
PCI: layerscape: Add power management support for ls1028a
Add PME_Turn_off/PME_TO_Ack handshake sequence for ls1028a platform.
Implemented on top of common dwc dw_pcie_suspend(resume)_noirq()
functions to handle system enter/exit suspend states.
Link: https://lore.kernel.org/r/20230821184815.2167131-4-Frank.Li@nxp.com
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
-rw-r--r-- | drivers/pci/controller/dwc/pci-layerscape.c | 140 |
1 files changed, 131 insertions, 9 deletions
diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c index ed5fb492fe08..b931d597656f 100644 --- a/drivers/pci/controller/dwc/pci-layerscape.c +++ b/drivers/pci/controller/dwc/pci-layerscape.c @@ -8,9 +8,11 @@ * Author: Minghuan Lian <Minghuan.Lian@freescale.com> */ +#include <linux/delay.h> #include <linux/kernel.h> #include <linux/interrupt.h> #include <linux/init.h> +#include <linux/iopoll.h> #include <linux/of_pci.h> #include <linux/of_platform.h> #include <linux/of_address.h> @@ -20,6 +22,7 @@ #include <linux/mfd/syscon.h> #include <linux/regmap.h> +#include "../../pci.h" #include "pcie-designware.h" /* PEX Internal Configuration Registers */ @@ -27,12 +30,26 @@ #define PCIE_ABSERR 0x8d0 /* Bridge Slave Error Response Register */ #define PCIE_ABSERR_SETTING 0x9401 /* Forward error of non-posted request */ +/* PF Message Command Register */ +#define LS_PCIE_PF_MCR 0x2c +#define PF_MCR_PTOMR BIT(0) +#define PF_MCR_EXL2S BIT(1) + #define PCIE_IATU_NUM 6 +struct ls_pcie_drvdata { + const u32 pf_off; + bool pm_support; +}; + struct ls_pcie { struct dw_pcie *pci; + const struct ls_pcie_drvdata *drvdata; + void __iomem *pf_base; + bool big_endian; }; +#define ls_pcie_pf_readl_addr(addr) ls_pcie_pf_readl(pcie, addr) #define to_ls_pcie(x) dev_get_drvdata((x)->dev) static bool ls_pcie_is_bridge(struct ls_pcie *pcie) @@ -73,6 +90,68 @@ static void ls_pcie_fix_error_response(struct ls_pcie *pcie) iowrite32(PCIE_ABSERR_SETTING, pci->dbi_base + PCIE_ABSERR); } +static u32 ls_pcie_pf_readl(struct ls_pcie *pcie, u32 off) +{ + if (pcie->big_endian) + return ioread32be(pcie->pf_base + off); + + return ioread32(pcie->pf_base + off); +} + +static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val) +{ + if (pcie->big_endian) + iowrite32be(val, pcie->pf_base + off); + else + iowrite32(val, pcie->pf_base + off); +} + +static void ls_pcie_send_turnoff_msg(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct ls_pcie *pcie = to_ls_pcie(pci); + u32 val; + int ret; + + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR); + val |= PF_MCR_PTOMR; + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val); + + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR, + val, !(val & PF_MCR_PTOMR), + PCIE_PME_TO_L2_TIMEOUT_US/10, + PCIE_PME_TO_L2_TIMEOUT_US); + if (ret) + dev_err(pcie->pci->dev, "PME_Turn_off timeout\n"); +} + +static void ls_pcie_exit_from_l2(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct ls_pcie *pcie = to_ls_pcie(pci); + u32 val; + int ret; + + /* + * Set PF_MCR_EXL2S bit in LS_PCIE_PF_MCR register for the link + * to exit L2 state. + */ + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR); + val |= PF_MCR_EXL2S; + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val); + + /* + * L2 exit timeout of 10ms is not defined in the specifications, + * it was chosen based on empirical observations. + */ + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR, + val, !(val & PF_MCR_EXL2S), + 1000, + 10000); + if (ret) + dev_err(pcie->pci->dev, "L2 exit timeout\n"); +} + static int ls_pcie_host_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); @@ -91,18 +170,28 @@ static int ls_pcie_host_init(struct dw_pcie_rp *pp) static const struct dw_pcie_host_ops ls_pcie_host_ops = { .host_init = ls_pcie_host_init, + .pme_turn_off = ls_pcie_send_turnoff_msg, +}; + +static const struct ls_pcie_drvdata ls1021a_drvdata = { + .pm_support = false, +}; + +static const struct ls_pcie_drvdata layerscape_drvdata = { + .pf_off = 0xc0000, + .pm_support = true, }; static const struct of_device_id ls_pcie_of_match[] = { - { .compatible = "fsl,ls1012a-pcie", }, - { .compatible = "fsl,ls1021a-pcie", }, - { .compatible = "fsl,ls1028a-pcie", }, - { .compatible = "fsl,ls1043a-pcie", }, - { .compatible = "fsl,ls1046a-pcie", }, - { .compatible = "fsl,ls2080a-pcie", }, - { .compatible = "fsl,ls2085a-pcie", }, - { .compatible = "fsl,ls2088a-pcie", }, - { .compatible = "fsl,ls1088a-pcie", }, + { .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata }, + { .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls1043a-pcie", .data = &ls1021a_drvdata }, + { .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls2088a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls1088a-pcie", .data = &layerscape_drvdata }, { }, }; @@ -121,6 +210,8 @@ static int ls_pcie_probe(struct platform_device *pdev) if (!pci) return -ENOMEM; + pcie->drvdata = of_device_get_match_data(dev); + pci->dev = dev; pci->pp.ops = &ls_pcie_host_ops; @@ -131,6 +222,10 @@ static int ls_pcie_probe(struct platform_device *pdev) if (IS_ERR(pci->dbi_base)) return PTR_ERR(pci->dbi_base); + pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian"); + + pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off; + if (!ls_pcie_is_bridge(pcie)) return -ENODEV; @@ -139,12 +234,39 @@ static int ls_pcie_probe(struct platform_device *pdev) return dw_pcie_host_init(&pci->pp); } +static int ls_pcie_suspend_noirq(struct device *dev) +{ + struct ls_pcie *pcie = dev_get_drvdata(dev); + + if (!pcie->drvdata->pm_support) + return 0; + + return dw_pcie_suspend_noirq(pcie->pci); +} + +static int ls_pcie_resume_noirq(struct device *dev) +{ + struct ls_pcie *pcie = dev_get_drvdata(dev); + + if (!pcie->drvdata->pm_support) + return 0; + + ls_pcie_exit_from_l2(&pcie->pci->pp); + + return dw_pcie_resume_noirq(pcie->pci); +} + +static const struct dev_pm_ops ls_pcie_pm_ops = { + NOIRQ_SYSTEM_SLEEP_PM_OPS(ls_pcie_suspend_noirq, ls_pcie_resume_noirq) +}; + static struct platform_driver ls_pcie_driver = { .probe = ls_pcie_probe, .driver = { .name = "layerscape-pcie", .of_match_table = ls_pcie_of_match, .suppress_bind_attrs = true, + .pm = &ls_pcie_pm_ops, }, }; builtin_platform_driver(ls_pcie_driver); |