[PATCH 3/4] soc/imx: add new GPC driver
Shawn Guo
shawnguo at kernel.org
Tue Jan 24 04:49:56 PST 2017
On Fri, Jan 20, 2017 at 04:52:24PM +0100, Lucas Stach wrote:
> This is an almost complete re-write of the previous GPC power gating control
> code found in the IMX architecture code. It supports both the old and the new
> DT binding, allowing more domains to be added later and generally makes the
> driver easier to extend, while keeping compatibility with existing DTBs.
Shouldn't we generally wrap the commit log around column 72?
>
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> ---
> drivers/soc/Makefile | 1 +
> drivers/soc/imx/Makefile | 1 +
> drivers/soc/imx/gpc.c | 480 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 482 insertions(+)
> create mode 100644 drivers/soc/imx/Makefile
> create mode 100644 drivers/soc/imx/gpc.c
>
> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
> index 50c23d0bd457..42b3fc7687bb 100644
> --- a/drivers/soc/Makefile
> +++ b/drivers/soc/Makefile
> @@ -6,6 +6,7 @@ obj-y += bcm/
> obj-$(CONFIG_ARCH_DOVE) += dove/
> obj-$(CONFIG_MACH_DOVE) += dove/
> obj-y += fsl/
> +obj-$(CONFIG_ARCH_MXC) += imx/
> obj-$(CONFIG_ARCH_MEDIATEK) += mediatek/
> obj-$(CONFIG_ARCH_QCOM) += qcom/
> obj-$(CONFIG_ARCH_RENESAS) += renesas/
> diff --git a/drivers/soc/imx/Makefile b/drivers/soc/imx/Makefile
> new file mode 100644
> index 000000000000..35861f5b2802
> --- /dev/null
> +++ b/drivers/soc/imx/Makefile
> @@ -0,0 +1 @@
> +obj-y += gpc.o
> diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c
> new file mode 100644
> index 000000000000..24bc0c6b72d8
> --- /dev/null
> +++ b/drivers/soc/imx/gpc.c
> @@ -0,0 +1,480 @@
> +/*
> + * Copyright 2015-2017 Pengutronix, Lucas Stach <kernel at pengutronix.de>
> + * Copyright 2011-2013 Freescale Semiconductor, Inc.
> + *
> + * 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>
> +
> +#define GPC_CNTR 0x000
> +
> +#define GPC_PGC_PDN_OFFS 0x0
> +#define GPC_PGC_PUPSCR_OFFS 0x4
> +#define GPC_PGC_PDNSCR_OFFS 0x8
> +#define GPC_PGC_SW2ISO_SHIFT 0x8
> +#define GPC_PGC_SW_SHIFT 0x0
> +
> +#define GPC_PGC_GPU_PDN 0x260
> +#define GPC_PGC_GPU_PUPSCR 0x264
> +#define GPC_PGC_GPU_PDNSCR 0x268
> +
> +#define GPU_VPU_PUP_REQ BIT(1)
> +#define GPU_VPU_PDN_REQ BIT(0)
> +
> +#define GPC_CLK_MAX 6
> +
> +struct imx_pm_domain {
> + struct generic_pm_domain base;
> + struct regmap *regmap;
> + struct regulator *supply;
> + struct clk *clk[GPC_CLK_MAX];
> + int num_clks;
> + unsigned int reg_offs;
> + signed char cntr_pdn_bit;
> + unsigned int ipg_rate_mhz;
> +};
> +
> +static inline struct imx_pm_domain *
> +to_imx_pm_domain(struct generic_pm_domain *genpd)
> +{
> + return container_of(genpd, struct imx_pm_domain, base);
> +}
> +
> +static int imx6_pm_domain_power_off(struct generic_pm_domain *genpd)
> +{
> + struct imx_pm_domain *pd = to_imx_pm_domain(genpd);
> + int iso, iso2sw;
> + u32 val;
> +
> + /* Read ISO and ISO2SW power down delays */
> + regmap_read(pd->regmap, pd->reg_offs + GPC_PGC_PUPSCR_OFFS, &val);
> + iso = val & 0x3f;
> + iso2sw = (val >> 8) & 0x3f;
> +
> + /* Gate off domain when powered down */
> + regmap_update_bits(pd->regmap, pd->reg_offs + GPC_PGC_PDN_OFFS,
> + 0x1, 0x1);
> +
> + /* Request GPC to power down domain */
> + val = BIT(pd->cntr_pdn_bit);
> + regmap_update_bits(pd->regmap, GPC_CNTR, val, val);
> +
> + /* Wait ISO + ISO2SW IPG clock cycles */
> + udelay(DIV_ROUND_UP(iso + iso2sw, pd->ipg_rate_mhz));
> +
> + if (pd->supply)
> + regulator_disable(pd->supply);
> +
> + return 0;
> +}
> +
> +static int imx6_pm_domain_power_on(struct generic_pm_domain *genpd)
> +{
> + struct imx_pm_domain *pd = to_imx_pm_domain(genpd);
> + int i, ret, sw, sw2iso;
> + u32 val;
> +
> + if (pd->supply) {
> + ret = regulator_enable(pd->supply);
> + if (ret) {
> + pr_err("%s: failed to enable regulator: %d\n",
> + __func__, ret);
> + return ret;
> + }
> + }
> +
> + /* Enable reset clocks for all devices in the domain */
> + for (i = 0; i < pd->num_clks; i++)
> + clk_prepare_enable(pd->clk[i]);
> +
> + /* Gate off domain when powered down */
> + regmap_update_bits(pd->regmap, pd->reg_offs + GPC_PGC_PDN_OFFS,
> + 0x1, 0x1);
> +
> + /* Read ISO and ISO2SW power down delays */
> + regmap_read(pd->regmap, pd->reg_offs + GPC_PGC_PUPSCR_OFFS, &val);
> + sw = val & 0x3f;
> + sw2iso = (val >> 8) & 0x3f;
> +
> + /* Request GPC to power up domain */
> + val = BIT(pd->cntr_pdn_bit + 1);
> + regmap_update_bits(pd->regmap, GPC_CNTR, val, val);
> +
> + /* Wait ISO + ISO2SW IPG clock cycles */
> + udelay(DIV_ROUND_UP(sw + sw2iso, pd->ipg_rate_mhz));
> +
> + /* Disable reset clocks for all devices in the domain */
> + for (i = 0; i < pd->num_clks; i++)
> + clk_disable_unprepare(pd->clk[i]);
> +
> + return 0;
> +}
> +
> +static int imx_pgc_get_clocks(struct device *dev, struct imx_pm_domain *domain)
> +{
> + int i, ret;
> +
> + for (i = 0; ; i++) {
> + struct clk *clk = of_clk_get(dev->of_node, i);
> + if (IS_ERR(clk))
> + break;
> + if (i >= GPC_CLK_MAX) {
> + dev_err(dev, "more than %d clocks\n", GPC_CLK_MAX);
> + ret = -EINVAL;
> + goto clk_err;
> + }
> + domain->clk[i] = clk;
> + }
> + domain->num_clks = i;
> +
> + return 0;
> +
> +clk_err:
> + for (; i >= 0; i--)
> + clk_put(domain->clk[i]);
> +
> + return ret;
> +}
> +
> +static void imx_pgc_put_clocks(struct imx_pm_domain *domain)
> +{
> + int i;
> +
> + for (i = domain->num_clks - 1; i >= 0; i--)
> + clk_put(domain->clk[i]);
> +}
> +
> +static int imx_pgc_parse_dt(struct device *dev, struct imx_pm_domain *domain)
> +{
> + /* try to get the domain supply regulator */
> + domain->supply = devm_regulator_get_optional(dev, "domain");
> + if (IS_ERR(domain->supply)) {
> + if (PTR_ERR(domain->supply) == -ENODEV)
> + domain->supply = NULL;
> + else
> + return PTR_ERR(domain->supply);
> + }
> +
> + /* try to get all clocks needed for reset propagation */
> + return imx_pgc_get_clocks(dev, domain);
> +}
> +
> +static int imx_pgc_power_domain_probe(struct platform_device *pdev)
> +{
> + struct imx_pm_domain *domain = pdev->dev.platform_data;
> + struct device *dev = &pdev->dev;
> + int ret;
> +
> + /* if this PD is associated with a DT node try to parse it */
> + if (dev->of_node) {
> + ret = imx_pgc_parse_dt(dev, domain);
> + if (ret)
> + return ret;
> + }
> +
> + /* initially power on the domain */
> + if (domain->base.power_on)
> + domain->base.power_on(&domain->base);
> +
> + if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
> + pm_genpd_init(&domain->base, NULL, false);
> + ret = of_genpd_add_provider_simple(dev->of_node, &domain->base);
> + if (ret)
> + goto genpd_err;
> + }
> +
> + return 0;
> +
> +genpd_err:
> + pm_genpd_remove(&domain->base);
> + imx_pgc_put_clocks(domain);
> +
> + return ret;
> +}
> +
> +static int imx_pgc_power_domain_remove(struct platform_device *pdev)
> +{
> + struct imx_pm_domain *domain = pdev->dev.platform_data;
> +
> + if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
> + of_genpd_del_provider(pdev->dev.of_node);
> + pm_genpd_remove(&domain->base);
> + imx_pgc_put_clocks(domain);
> + }
> +
> + return 0;
> +}
> +
> +static const struct platform_device_id imx_pgc_power_domain_id[] = {
> + { "imx-pgc-power-domain"},
> + { },
> +};
> +
> +static struct platform_driver imx_pgc_power_domain_driver = {
> + .driver = {
> + .name = "imx-pgc-pd",
> + },
> + .probe = imx_pgc_power_domain_probe,
> + .remove = imx_pgc_power_domain_remove,
Not sure how .remove hook is going to be useful for a
builtin_platform_driver.
> + .id_table = imx_pgc_power_domain_id,
> +};
> +builtin_platform_driver(imx_pgc_power_domain_driver)
> +
> +static struct genpd_power_state imx6_pm_domain_pu_state = {
> + .power_off_latency_ns = 25000,
> + .power_on_latency_ns = 2000000,
> +};
> +
> +static struct imx_pm_domain imx_gpc_domains[] = {
> + {
> + .base = {
> + .name = "ARM",
> + },
> + }, {
> + .base = {
> + .name = "PU",
> + .power_off = imx6_pm_domain_power_off,
> + .power_on = imx6_pm_domain_power_on,
> + .states = &imx6_pm_domain_pu_state,
> + .state_count = 1,
> + },
> + .reg_offs = 0x260,
> + .cntr_pdn_bit = 0,
> + }, {
> + .base = {
> + .name = "DISPLAY",
> + .power_off = imx6_pm_domain_power_off,
> + .power_on = imx6_pm_domain_power_on,
> + },
> + .reg_offs = 0x240,
> + .cntr_pdn_bit = 4,
> + }
> +};
> +
> +struct imx_gpc_dt_data {
> + int num_domains;
> +};
> +
> +static const struct imx_gpc_dt_data imx6q_dt_data = {
> + .num_domains = 2,
> +};
> +
> +static const struct imx_gpc_dt_data imx6sl_dt_data = {
> + .num_domains = 3,
> +};
> +
> +static const struct of_device_id imx_gpc_dt_ids[] = {
> + { .compatible = "fsl,imx6q-gpc", .data = &imx6q_dt_data },
> + { .compatible = "fsl,imx6sl-gpc", .data = &imx6sl_dt_data },
> + { }
> +};
> +
> +static bool imx_gpc_readable_reg(struct device *dev, unsigned int reg)
> +{
> + return (reg % 4 == 0) && (reg <= 0x2ac);
> +}
> +
> +static bool imx_gpc_volatile_reg(struct device *dev, unsigned int reg)
> +{
> + if (reg == GPC_CNTR)
> + return true;
> +
> + return false;
> +}
> +
> +static const struct regmap_config imx_gpc_regmap_config = {
> + .cache_type = REGCACHE_FLAT,
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> +
> + .readable_reg = imx_gpc_readable_reg,
> + .volatile_reg = imx_gpc_volatile_reg,
> +
> + .max_register = 0x2ac,
> +};
> +
> +static struct generic_pm_domain *imx_gpc_onecell_domains[] = {
> + &imx_gpc_domains[0].base,
> + &imx_gpc_domains[1].base,
> +};
> +
> +static struct genpd_onecell_data imx_gpc_onecell_data = {
> + .domains = imx_gpc_onecell_domains,
> + .num_domains = 2,
> +};
> +
> +static int imx_gpc_old_dt_init(struct device *dev, struct regmap *regmap)
> +{
> + struct imx_pm_domain *domain;
> + int i, ret;
> +
> + for (i = 0; i < 2; i++) {
> + domain = &imx_gpc_domains[i];
> + domain->regmap = regmap;
> + domain->ipg_rate_mhz = 33;
I see it's being 66MHz in the existing driver code. What's the reason
behind this change?
> +
> + if (i == 1) {
> + domain->supply = devm_regulator_get(dev, "pu");
> + if (IS_ERR(domain->supply))
> + return PTR_ERR(domain->supply);;
> +
> + ret = imx_pgc_get_clocks(dev, domain);
> + if (ret)
> + goto clk_err;
> +
> + domain->base.power_on(&domain->base);
> + }
> + }
> +
> + for (i = 0; i < 2; i++)
> + pm_genpd_init(&imx_gpc_domains[i].base, NULL, false);
> +
> + if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) {
> + ret = of_genpd_add_provider_onecell(dev->of_node,
> + &imx_gpc_onecell_data);
> + if (ret)
> + goto genpd_err;
> + }
> +
> + return 0;
> +
> +genpd_err:
> + pm_genpd_remove(&imx_gpc_domains[1].base);
> + imx_pgc_put_clocks(&imx_gpc_domains[1]);
> +clk_err:
> + pm_genpd_remove(&imx_gpc_domains[0].base);
I do not think that imx_gpc_domains[0].base is already registered on
clk_err path.
> +
> + return ret;
> +}
> +
> +static int imx_gpc_probe(struct platform_device *pdev)
> +{
> + const struct of_device_id *of_id =
> + of_match_device(imx_gpc_dt_ids, &pdev->dev);
> + const struct imx_gpc_dt_data *of_id_data = of_id->data;
> + struct device_node *pgc_node;
> + struct regmap *regmap;
> + struct resource *res;
> + void __iomem *base;
> + int ret;
> +
> + pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");
> +
> + /* bail out if DT too old and doesn't provide the necessary info */
> + if (!of_property_read_bool(pdev->dev.of_node, "#power-domain-cells") &&
> + !pgc_node)
> + return 0;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
> + &imx_gpc_regmap_config);
> + if (IS_ERR(regmap)) {
> + ret = PTR_ERR(regmap);
> + dev_err(&pdev->dev, "failed to init regmap: %d\n",
> + ret);
> + return ret;
> + }
> +
> + if (!pgc_node) {
> + /* old DT layout is only supported for mx6q aka 2 domains */
> + if (of_id_data->num_domains != 2) {
> + dev_err(&pdev->dev, "could not find pgc DT node\n");
> + return -ENODEV;
> + }
> +
> + ret = imx_gpc_old_dt_init(&pdev->dev, regmap);
> + if (ret)
> + return ret;
> + } else {
> + struct imx_pm_domain *domain;
> + struct platform_device *pd_pdev;
> + struct device_node *np;
> + struct clk *ipg_clk;
> + unsigned int ipg_rate_mhz;
> + int domain_index;
> +
> + ipg_clk = devm_clk_get(&pdev->dev, "ipg");
> + if (IS_ERR(ipg_clk))
> + return PTR_ERR(ipg_clk);
> + ipg_rate_mhz = clk_get_rate(ipg_clk) / 1000000;
> +
> + for_each_child_of_node(pgc_node, np) {
> + ret = of_property_read_u32(np, "reg", &domain_index);
> + if (ret) {
> + of_node_put(np);
> + return ret;
> + }
Should we have a check here to ensure that domain_index doesn't exceed
imx_gpc_domains[] array size?
Shawn
> +
> + domain = &imx_gpc_domains[domain_index];
> + domain->regmap = regmap;
> + domain->ipg_rate_mhz = ipg_rate_mhz;
> +
> + pd_pdev = platform_device_alloc("imx-pgc-power-domain",
> + domain_index);
> + pd_pdev->dev.platform_data = domain;
> + pd_pdev->dev.parent = &pdev->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 int imx_gpc_remove(struct platform_device *pdev)
> +{
> + int ret;
> +
> + /*
> + * If the old DT binding is used the toplevel driver needs to
> + * de-register the power domains
> + */
> + if (!of_get_child_by_name(pdev->dev.of_node, "pgc")) {
> + of_genpd_del_provider(pdev->dev.of_node);
> +
> + ret = pm_genpd_remove(&imx_gpc_domains[1].base);
> + if (ret)
> + return ret;
> + imx_pgc_put_clocks(&imx_gpc_domains[1]);
> +
> + ret = pm_genpd_remove(&imx_gpc_domains[0].base);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static struct platform_driver imx_gpc_driver = {
> + .driver = {
> + .name = "imx-gpc",
> + .of_match_table = imx_gpc_dt_ids,
> + },
> + .probe = imx_gpc_probe,
> + .remove = imx_gpc_remove,
> +};
> +builtin_platform_driver(imx_gpc_driver)
> --
> 2.11.0
>
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