Re: [PATCH v5 2/3] soc/imx: Add GPCv2 power gating driver

From: Shawn Guo
Date: Wed Mar 15 2017 - 23:41:04 EST

On Tue, Mar 14, 2017 at 08:05:39AM -0700, Andrey Smirnov wrote:
> Add code allowing for control of various power domains managed by GPCv2
> IP block found in i.MX7 series of SoCs. Power domains covered by this
> patch are:
>
> - PCIE PHY
> - MIPI PHY
> - USB HSIC PHY
> - USB OTG1/2 PHY
>
> Support for any other power domain controlled by GPC is not present, and
> can be added at some later point.
>
> Testing of this code was done against a PCIe driver.
>
> Cc: yurovsky@xxxxxxxxx
> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Cc: Fabio Estevam <fabio.estevam@xxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> ---
> drivers/soc/Kconfig | 1 +
> drivers/soc/imx/Kconfig | 9 ++
> drivers/soc/imx/Makefile | 1 +
> drivers/soc/imx/gpcv2.c | 387 +++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 398 insertions(+)
> create mode 100644 drivers/soc/imx/Kconfig
> create mode 100644 drivers/soc/imx/gpcv2.c
>
> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
> index f31bceb..55a4eb8 100644
> --- a/drivers/soc/Kconfig
> +++ b/drivers/soc/Kconfig
> @@ -2,6 +2,7 @@ menu "SOC (System On Chip) specific Drivers"
>
> source "drivers/soc/bcm/Kconfig"
> source "drivers/soc/fsl/Kconfig"
> +source "drivers/soc/imx/Kconfig"
> source "drivers/soc/mediatek/Kconfig"
> source "drivers/soc/qcom/Kconfig"
> source "drivers/soc/rockchip/Kconfig"
> diff --git a/drivers/soc/imx/Kconfig b/drivers/soc/imx/Kconfig
> new file mode 100644
> index 0000000..9c84eb0
> --- /dev/null
> +++ b/drivers/soc/imx/Kconfig
> @@ -0,0 +1,9 @@
> +menu "i.MX SoC drivers"
> +
> +config IMX7_PM_DOMAINS
> + bool "i.MX7 PM domains"
> + select PM_GENERIC_DOMAINS
> + depends on SOC_IMX7D || (COMPILE_TEST && OF)

Can we do something like below to save the patch #3?

default y if SOC_IMX7D

> +
> +endmenu
> +
> diff --git a/drivers/soc/imx/Makefile b/drivers/soc/imx/Makefile
> index 35861f5..5b6e396 100644
> --- a/drivers/soc/imx/Makefile
> +++ b/drivers/soc/imx/Makefile
> @@ -1 +1,2 @@
> obj-y += gpc.o
> +obj-$(CONFIG_IMX7_PM_DOMAINS) += gpcv2.o
> diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c
> new file mode 100644
> index 0000000..7d52141
> --- /dev/null
> +++ b/drivers/soc/imx/gpcv2.c
> @@ -0,0 +1,387 @@
> +/*
> + * Copyright 2017 Impinj, Inc
> + * Author: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> + *
> + * Based on the code of analogus driver:
> + *
> + * Copyright 2015-2017 Pengutronix, Lucas Stach <kernel@xxxxxxxxxxxxxx>
> + *
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <dt-bindings/power/imx7-power.h>
> +
> +#define GPC_PGC_CPU_MAPPING 0xec
> +#define USB_HSIC_PHY_A7_DOMAIN BIT(6)
> +#define USB_OTG2_PHY_A7_DOMAIN BIT(5)
> +#define USB_OTG1_PHY_A7_DOMAIN BIT(4)
> +#define PCIE_PHY_A7_DOMAIN BIT(3)
> +#define MIPI_PHY_A7_DOMAIN BIT(2)
> +
> +#define GPC_PU_PGC_SW_PUP_REQ 0xf8
> +#define GPC_PU_PGC_SW_PDN_REQ 0x104
> +#define USB_HSIC_PHY_SW_Pxx_REQ BIT(4)
> +#define USB_OTG2_PHY_SW_Pxx_REQ BIT(3)
> +#define USB_OTG1_PHY_SW_Pxx_REQ BIT(2)
> +#define PCIE_PHY_SW_Pxx_REQ BIT(1)
> +#define MIPI_PHY_SW_Pxx_REQ BIT(0)
> +
> +#define GPC_MAX_REGISTER 0x1000
> +
> +#define GPC_PGC_nCTRL_PCR BIT(0)
> +
> +struct imx7_pgc_domain {
> + struct generic_pm_domain genpd;
> + struct regmap *regmap;
> + struct regulator *regulator;
> +
> + unsigned int pgc_nctrl;
> +
> + const struct {
> + u32 pxx;
> + u32 map;
> + } bits;
> +
> + const int voltage;
> + struct device *dev;
> +};
> +
> +static int imx7_gpc_pu_pgc_sw_pxx_req(struct generic_pm_domain *genpd,
> + bool on)
> +{
> + int ret = 0;
> + unsigned long deadline;
> + struct imx7_pgc_domain *domain = container_of(genpd,
> + struct imx7_pgc_domain,
> + genpd);
> + unsigned int offset = on ?
> + GPC_PU_PGC_SW_PUP_REQ : GPC_PU_PGC_SW_PDN_REQ;
> +
> + const bool enable_power_control = domain->pgc_nctrl && !on;
> + const bool has_regulator = !IS_ERR(domain->regulator);

Again, reverse tree for variable declaration section, and drop the
newline in middle of it please.

Shawn

> +
> + regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
> + domain->bits.map, domain->bits.map);
> +
> + if (has_regulator && on) {
> + ret = regulator_enable(domain->regulator);
> + if (ret) {
> + dev_err(domain->dev, "failed to enable regulator\n");
> + goto unmap;
> + }
> + }
> +
> + if (enable_power_control)
> + regmap_update_bits(domain->regmap, domain->pgc_nctrl,
> + GPC_PGC_nCTRL_PCR, GPC_PGC_nCTRL_PCR);
> +
> + regmap_update_bits(domain->regmap, offset,
> + domain->bits.pxx, domain->bits.pxx);
> +
> + /*
> + * As per "5.5.9.4 Example Code 4" in IMX7DRM.pdf wait
> + * for PUP_REQ/PDN_REQ bit to be cleared
> + */
> + deadline = jiffies + msecs_to_jiffies(1);
> + while (true) {
> + u32 pxx_req;
> +
> + regmap_read(domain->regmap, offset, &pxx_req);
> +
> + if (!(pxx_req & domain->bits.pxx))
> + break;
> +
> + if (time_after(jiffies, deadline)) {
> + dev_err(domain->dev, "falied to command PGC\n");
> + ret = -ETIMEDOUT;
> + /*
> + * If we were in a process of enabling a
> + * domain and failed we might as well disable
> + * the regulator we just enabled. And if it
> + * was the opposite situation and we failed to
> + * power down -- keep the regulator on
> + */
> + on = !on;
> + break;
> + }
> +
> + cpu_relax();
> + }
> +
> + if (enable_power_control)
> + regmap_update_bits(domain->regmap, domain->pgc_nctrl,
> + GPC_PGC_nCTRL_PCR, 0);
> +
> + if (has_regulator && !on) {
> + int err;
> +
> + err = regulator_disable(domain->regulator);
> + if (err)
> + dev_err(domain->dev,
> + "failed to disable regulator: %d\n", ret);
> + /* Preserve earlier error code */
> + ret = ret ?: err;
> + }
> +unmap:
> + regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,
> + domain->bits.map, 0);
> + return ret;
> +}
> +
> +static int imx7_gpc_pu_pgc_sw_pup_req(struct generic_pm_domain *genpd)
> +{
> + return imx7_gpc_pu_pgc_sw_pxx_req(genpd, true);
> +}
> +
> +static int imx7_gpc_pu_pgc_sw_pdn_req(struct generic_pm_domain *genpd)
> +{
> + return imx7_gpc_pu_pgc_sw_pxx_req(genpd, false);
> +}
> +
> +static struct imx7_pgc_domain imx7_pgc_domains[] = {
> + [IMX7_POWER_DOMAIN_USB_HSIC_PHY] = {
> + .genpd = {
> + .name = "usb-hsic-phy",
> + },
> + .bits = {
> + .pxx = USB_HSIC_PHY_SW_Pxx_REQ,
> + .map = USB_HSIC_PHY_A7_DOMAIN,
> + },
> + .voltage = 1200000,
> + .pgc_nctrl = 0x0d00,
> + },
> +
> + [IMX7_POWER_DOMAIN_USB_OTG2_PHY] = {
> + .genpd = {
> + .name = "usb-otg2-phy",
> + },
> + .bits = {
> + .pxx = USB_OTG2_PHY_SW_Pxx_REQ,
> + .map = USB_OTG2_PHY_A7_DOMAIN,
> + },
> + },
> +
> + [IMX7_POWER_DOMAIN_USB_OTG1_PHY] = {
> + .genpd = {
> + .name = "usb-otg1-phy",
> + },
> + .bits = {
> + .pxx = USB_OTG1_PHY_SW_Pxx_REQ,
> + .map = USB_OTG1_PHY_A7_DOMAIN,
> + },
> + },
> +
> + [IMX7_POWER_DOMAIN_PCIE_PHY] = {
> + .genpd = {
> + .name = "pcie-phy",
> + },
> + .bits = {
> + .pxx = PCIE_PHY_SW_Pxx_REQ,
> + .map = PCIE_PHY_A7_DOMAIN,
> + },
> + .voltage = 1000000,
> + .pgc_nctrl = 0x0c40,
> + },
> +
> + [IMX7_POWER_DOMAIN_MIPI_PHY] = {
> + .genpd = {
> + .name = "mipi-phy",
> + },
> + .bits = {
> + .pxx = MIPI_PHY_SW_Pxx_REQ,
> + .map = MIPI_PHY_A7_DOMAIN,
> + },
> + .voltage = 1000000,
> + .pgc_nctrl = 0x0c00,
> + },
> +};
> +
> +static int imx7_pgc_domain_probe(struct platform_device *pdev)
> +{
> + struct imx7_pgc_domain *domain = pdev->dev.platform_data;
> + int ret;
> +
> + domain->dev = &pdev->dev;
> +
> + ret = pm_genpd_init(&domain->genpd, NULL, true);
> + if (ret) {
> + dev_err(domain->dev, "Failed to init power domain\n");
> + return ret;
> + }
> +
> + domain->regulator = devm_regulator_get_optional(domain->dev, "power");
> + if (IS_ERR(domain->regulator) &&
> + PTR_ERR(domain->regulator) != -ENODEV) {
> + dev_err(domain->dev, "Failed to get domain's regulator\n");
> + return PTR_ERR(domain->regulator);
> + }
> +
> + if (!IS_ERR(domain->regulator)) {
> + if (!domain->voltage) {
> + WARN(1, "No voltage configured for domain's regulator");
> + return -EINVAL;
> + }
> +
> + regulator_set_voltage(domain->regulator,
> + domain->voltage, domain->voltage);
> + }
> +
> + ret = of_genpd_add_provider_simple(domain->dev->of_node,
> + &domain->genpd);
> + if (ret) {
> + dev_err(domain->dev, "Failed to add genpd provider\n");
> + pm_genpd_remove(&domain->genpd);
> + }
> +
> + return ret;
> +}
> +
> +static int imx7_pgc_domain_remove(struct platform_device *pdev)
> +{
> + struct imx7_pgc_domain *domain = pdev->dev.platform_data;
> +
> + of_genpd_del_provider(domain->dev->of_node);
> + pm_genpd_remove(&domain->genpd);
> +
> + return 0;
> +}
> +
> +static const struct platform_device_id imx7_pgc_domain_id[] = {
> + { "imx7-pgc-domain", },
> + { },
> +};
> +
> +static struct platform_driver imx7_pgc_domain_driver = {
> + .driver = {
> + .name = "imx7-pgc",
> + },
> + .probe = imx7_pgc_domain_probe,
> + .remove = imx7_pgc_domain_remove,
> + .id_table = imx7_pgc_domain_id,
> +};
> +builtin_platform_driver(imx7_pgc_domain_driver)
> +
> +static bool imx_gpcv2_readable_reg(struct device *dev, unsigned int reg)
> +{
> + return reg % 4 == 0 &&
> + reg <= GPC_MAX_REGISTER;
> +}
> +
> +static bool imx_gpcv2_volatile_reg(struct device *dev, unsigned int reg)
> +{
> + return reg == GPC_PU_PGC_SW_PUP_REQ ||
> + reg == GPC_PU_PGC_SW_PDN_REQ;
> +}
> +
> +static int imx_gpcv2_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *pgc_np, *np;
> + struct regmap *regmap;
> + struct resource *res;
> + void __iomem *base;
> + int ret;
> +
> + static const struct regmap_config regmap_config = {
> + .cache_type = REGCACHE_FLAT,
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> +
> + .readable_reg = imx_gpcv2_readable_reg,
> + .volatile_reg = imx_gpcv2_volatile_reg,
> +
> + .max_register = GPC_MAX_REGISTER,
> + };
> +
> + pgc_np = of_get_child_by_name(dev->of_node, "pgc");
> + if (!pgc_np) {
> + dev_err(dev, "No power domains specified in DT\n");
> + return -EINVAL;
> + }
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + regmap = devm_regmap_init_mmio(dev, base, &regmap_config);
> + if (IS_ERR(regmap)) {
> + ret = PTR_ERR(regmap);
> + dev_err(dev, "failed to init regmap (%d)\n", ret);
> + return ret;
> + }
> +
> + for_each_child_of_node(pgc_np, np) {
> + struct platform_device *pd_pdev;
> + struct imx7_pgc_domain *domain;
> + u32 domain_index;
> +
> + ret = of_property_read_u32(np, "reg", &domain_index);
> + if (ret) {
> + dev_err(dev, "Failed to read 'reg' property\n");
> + of_node_put(np);
> + return ret;
> + }
> +
> + if (domain_index >= ARRAY_SIZE(imx7_pgc_domains)) {
> + dev_warn(dev,
> + "Domain index %d is out of bounds\n",
> + domain_index);
> + continue;
> + }
> +
> + domain = &imx7_pgc_domains[domain_index];
> + domain->regmap = regmap;
> + domain->genpd.power_on = imx7_gpc_pu_pgc_sw_pup_req;
> + domain->genpd.power_off = imx7_gpc_pu_pgc_sw_pdn_req;
> +
> + pd_pdev = platform_device_alloc("imx7-pgc-domain",
> + domain_index);
> + if (!pd_pdev) {
> + dev_err(dev, "Failed to allocate platform device\n");
> + of_node_put(np);
> + return -ENOMEM;
> + }
> +
> + pd_pdev->dev.platform_data = domain;
> + pd_pdev->dev.parent = dev;
> + pd_pdev->dev.of_node = np;
> +
> + ret = platform_device_add(pd_pdev);
> + if (ret) {
> + platform_device_put(pd_pdev);
> + of_node_put(np);
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static const struct of_device_id imx_gpcv2_dt_ids[] = {
> + { .compatible = "fsl,imx7d-gpc" },
> + { }
> +};
> +
> +static struct platform_driver imx_gpc_driver = {
> + .driver = {
> + .name = "imx-gpcv2",
> + .of_match_table = imx_gpcv2_dt_ids,
> + },
> + .probe = imx_gpcv2_probe,
> +};
> +builtin_platform_driver(imx_gpc_driver)
> --
> 2.9.3
>