[PATCH v2 2/7] ARM: imx6: gpc: Add PU power domain for GPU/VPU
Philipp Zabel
p.zabel at pengutronix.de
Thu Feb 13 11:41:52 EST 2014
Am Donnerstag, den 13.02.2014, 15:39 +0100 schrieb Philipp Zabel:
> When generic pm domain support is enabled, the PGC can be used
> to completely gate power to the PU power domain containing GPU3D,
> GPU2D, and VPU cores.
> This code triggers the PGC powerdown sequence to disable the GPU/VPU
> isolation cells and gate power and then disables the PU regulator.
> To reenable, the reverse powerup sequence is triggered after the PU
> regulaotor is enabled again.
>
> Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
> ---
> Changes since v1:
> - Removed superfluous comment
> - Link PU domain with its DT node, check for PU domain in bus notifier
> - Turn off the PU power domain on boot
> ---
> arch/arm/mach-imx/Kconfig | 2 +
> arch/arm/mach-imx/gpc.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 172 insertions(+)
>
> diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> index 33567aa..3c58f2e 100644
> --- a/arch/arm/mach-imx/Kconfig
> +++ b/arch/arm/mach-imx/Kconfig
> @@ -808,6 +808,7 @@ config SOC_IMX6Q
> select PL310_ERRATA_727915 if CACHE_PL310
> select PL310_ERRATA_769419 if CACHE_PL310
> select PM_OPP if PM
> + select PM_GENERIC_DOMAINS if PM
>
> help
> This enables support for Freescale i.MX6 Quad processor.
> @@ -827,6 +828,7 @@ config SOC_IMX6SL
> select PL310_ERRATA_588369 if CACHE_PL310
> select PL310_ERRATA_727915 if CACHE_PL310
> select PL310_ERRATA_769419 if CACHE_PL310
> + select PM_GENERIC_DOMAINS if PM
>
> help
> This enables support for Freescale i.MX6 SoloLite processor.
> diff --git a/arch/arm/mach-imx/gpc.c b/arch/arm/mach-imx/gpc.c
> index 586e017..1dc4301 100644
> --- a/arch/arm/mach-imx/gpc.c
> +++ b/arch/arm/mach-imx/gpc.c
> @@ -10,19 +10,32 @@
> * http://www.gnu.org/copyleft/gpl.html
> */
>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> #include <linux/io.h>
> #include <linux/irq.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/irqchip/arm-gic.h>
> #include "common.h"
> +#include "hardware.h"
>
> +#define GPC_CNTR 0x000
> #define GPC_IMR1 0x008
> +#define GPC_PGC_GPU_PDN 0x260
> +#define GPC_PGC_GPU_PUPSCR 0x264
> +#define GPC_PGC_GPU_PDNSCR 0x268
> #define GPC_PGC_CPU_PDN 0x2a0
>
> #define IMR_NUM 4
>
> +#define GPU_VPU_PUP_REQ BIT(1)
> +#define GPU_VPU_PDN_REQ BIT(0)
> +
> static void __iomem *gpc_base;
> static u32 gpc_wake_irqs[IMR_NUM];
> static u32 gpc_saved_imrs[IMR_NUM];
> @@ -138,3 +151,160 @@ void __init imx_gpc_init(void)
> gic_arch_extn.irq_unmask = imx_gpc_irq_unmask;
> gic_arch_extn.irq_set_wake = imx_gpc_irq_set_wake;
> }
> +
> +static struct regulator *pu_reg;
> +
> +static int imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
> +{
> + u32 val;
> + int iso, iso2sw;
> +
> + /* Read ISO and ISO2SW power down delays */
> + val = readl_relaxed(gpc_base + GPC_PGC_GPU_PDNSCR);
> + iso = val & 0x3f;
> + iso2sw = (val >> 8) & 0x3f;
> +
> + /* Gate off PU domain when GPU/VPU when powered down */
> + writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);
> +
> + /* Request GPC to power down GPU/VPU */
> + val = readl_relaxed(gpc_base + GPC_CNTR);
> + val |= GPU_VPU_PDN_REQ;
> + writel_relaxed(val, gpc_base + GPC_CNTR);
> +
> + /* Wait ISO + ISO2SW IPG clock cycles */
> + ndelay((iso + iso2sw) * 1000 / 66);
> +
> + regulator_disable(pu_reg);
> +
> + return 0;
> +}
> +
> +static int imx6q_pm_pu_power_on(struct generic_pm_domain *genpd)
> +{
> + int ret;
> + u32 val;
> + int sw, sw2iso;
> +
> + ret = regulator_enable(pu_reg);
> + if (ret) {
> + pr_err("%s: failed to enable regulator: %d\n", __func__, ret);
> + return ret;
> + }
> +
> + /* Gate off PU domain when GPU/VPU when powered down */
> + writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);
> +
> + /* Read ISO and ISO2SW power down delays */
> + val = readl_relaxed(gpc_base + GPC_PGC_GPU_PUPSCR);
> + sw = val & 0x3f;
> + sw2iso = (val >> 8) & 0x3f;
> +
> + /* Request GPC to power up GPU/VPU */
> + val = readl_relaxed(gpc_base + GPC_CNTR);
> + val |= GPU_VPU_PUP_REQ;
> + writel_relaxed(val, gpc_base + GPC_CNTR);
> +
> + /* Wait ISO + ISO2SW IPG clock cycles */
> + ndelay((sw + sw2iso) * 1000 / 66);
> +
> + return 0;
> +}
> +
> +static struct generic_pm_domain imx6q_pu_domain = {
> + .name = "PU",
> + .power_off = imx6q_pm_pu_power_off,
> + .power_on = imx6q_pm_pu_power_on,
> +};
> +
> +static int imx6q_pm_notifier_call(struct notifier_block *nb,
> + unsigned long event, void *data)
> +{
> + struct generic_pm_domain *genpd;
> + struct device *dev = data;
> + struct device_node *np;
> + int ret;
> +
> + switch (event) {
> + case BUS_NOTIFY_BIND_DRIVER:
> + np = of_parse_phandle(dev->of_node, "power-domain", 0);
> + if (!np || np != imx6q_pu_domain.of_node)
> + return NOTIFY_DONE;
> +
> + ret = pm_genpd_of_add_device(np, dev);
> + if (ret)
> + dev_err(dev, "failed to add to power domain: %d\n",
> + ret);
> + break;
> + case BUS_NOTIFY_UNBOUND_DRIVER:
> + genpd = dev_to_genpd(dev);
> + if (IS_ERR(genpd) || genpd != &imx6q_pu_domain)
> + return NOTIFY_DONE;
> +
> + ret = pm_genpd_remove_device(genpd, dev);
> + if (ret)
> + dev_err(dev, "failed to remove from power domain: %d\n",
> + ret);
> + break;
> + }
> +
> + return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block imx6q_platform_nb = {
> + .notifier_call = imx6q_pm_notifier_call,
> +};
> +
> +static int imx_gpc_probe(struct platform_device *pdev)
> +{
> + struct device_node *np;
> + int ret;
> +
> + np = of_get_child_by_name(pdev->dev.of_node, "pu-power-domain");
> + if (!np) {
> + dev_err(&pdev->dev, "missing pu-power-domain node\n");
> + return -EINVAL;
> + }
> + imx6q_pu_domain.of_node = np;
> +
> + pu_reg = devm_regulator_get(&pdev->dev, "pu");
> + if (IS_ERR(pu_reg)) {
> + ret = PTR_ERR(pu_reg);
> + dev_err(&pdev->dev, "failed to get pu regulator: %d\n", ret);
> + return ret;
> + }
> +
> + /* The regulator is initially enabled */
> + ret = regulator_enable(pu_reg);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to enable pu regulator: %d\n", ret);
> + return ret;
> + }
> +
> + imx6q_pu_domain.of_node = np;
> + imx6q_pm_pu_power_off(&imx6q_pu_domain);
> + pm_genpd_init(&imx6q_pu_domain, NULL, true);
Turning off the PU power domain and supply voltage on boot isn't a good
idea if the kernel doesn't have runtime PM support compiled in. In that
case it should be left enabled:
--- a/arch/arm/mach-imx/gpc.c
+++ b/arch/arm/mach-imx/gpc.c
@@ -366,8 +366,12 @@ static int imx_gpc_probe(struct platform_device *pdev)
regulator_allow_bypass(pu_reg, true);
imx6q_pu_domain.of_node = np;
+#ifdef CONFIG_PM_RUNTIME
imx6q_pm_pu_power_off(&imx6q_pu_domain);
pm_genpd_init(&imx6q_pu_domain, NULL, true);
+#else
+ pm_genpd_init(&imx6q_pu_domain, NULL, false);
+#endif
bus_register_notifier(&platform_bus_type, &imx6q_platform_nb);
return 0;
> + bus_register_notifier(&platform_bus_type, &imx6q_platform_nb);
> +
> + return 0;
> +}
> +
> +static struct of_device_id imx_gpc_dt_ids[] = {
> + { .compatible = "fsl,imx6q-gpc" },
> + { }
> +};
> +
> +static struct platform_driver imx_gpc_driver = {
> + .driver = {
> + .name = "imx-gpc",
> + .owner = THIS_MODULE,
> + .of_match_table = imx_gpc_dt_ids,
> + },
> + .probe = imx_gpc_probe,
> +};
> +
> +static int __init imx_pgc_init(void)
> +{
> + return platform_driver_register(&imx_gpc_driver);
> +}
> +subsys_initcall(imx_pgc_init);
regards
Philipp
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