2020-10-01 16:03:53

by Enric Balletbo i Serra

[permalink] [raw]
Subject: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

The System Control Processor System (SCPSYS) has several power management
related tasks in the system. This driver implements support to handle
the different power domains supported in order to meet high performance
and low power requirements.

Co-developed-by: Matthias Brugger <[email protected]>
Signed-off-by: Matthias Brugger <[email protected]>
Signed-off-by: Enric Balletbo i Serra <[email protected]>
---

Changes in v2:
- Get base address from parent syscon. We have now a scpsys syscon node
and a child for the SPM (System Power Manager).
- Use regmap API to acces de base address.

drivers/soc/mediatek/Kconfig | 13 +
drivers/soc/mediatek/Makefile | 1 +
drivers/soc/mediatek/mtk-pm-domains.c | 628 ++++++++++++++++++++++++++
3 files changed, 642 insertions(+)
create mode 100644 drivers/soc/mediatek/mtk-pm-domains.c

diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
index 59a56cd790ec..68d800f9e4a5 100644
--- a/drivers/soc/mediatek/Kconfig
+++ b/drivers/soc/mediatek/Kconfig
@@ -44,6 +44,19 @@ config MTK_SCPSYS
Say yes here to add support for the MediaTek SCPSYS power domain
driver.

+config MTK_SCPSYS_PM_DOMAINS
+ bool "MediaTek SCPSYS generic power domain"
+ default ARCH_MEDIATEK
+ depends on PM
+ depends on MTK_INFRACFG
+ select PM_GENERIC_DOMAINS
+ select REGMAP
+ help
+ Say y here to enable power domain support.
+ In order to meet high performance and low power requirements, the System
+ Control Processor System (SCPSYS) has several power management related
+ tasks in the system.
+
config MTK_MMSYS
bool "MediaTek MMSYS Support"
default ARCH_MEDIATEK
diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
index 01f9f873634a..1e60fb4f89d4 100644
--- a/drivers/soc/mediatek/Makefile
+++ b/drivers/soc/mediatek/Makefile
@@ -3,4 +3,5 @@ obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
+obj-$(CONFIG_MTK_SCPSYS_PM_DOMAINS) += mtk-pm-domains.o
obj-$(CONFIG_MTK_MMSYS) += mtk-mmsys.o
diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
new file mode 100644
index 000000000000..68886bf437f9
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-pm-domains.c
@@ -0,0 +1,628 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2020 Collabora Ltd.
+ */
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_clk.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/soc/mediatek/infracfg.h>
+
+#include <dt-bindings/power/mt8173-power.h>
+
+#define MTK_POLL_DELAY_US 10
+#define MTK_POLL_TIMEOUT USEC_PER_SEC
+
+#define MTK_SCPD_ACTIVE_WAKEUP BIT(0)
+#define MTK_SCPD_FWAIT_SRAM BIT(1)
+#define MTK_SCPD_CAPS(_scpd, _x) ((_scpd)->data->caps & (_x))
+
+#define SPM_VDE_PWR_CON 0x0210
+#define SPM_MFG_PWR_CON 0x0214
+#define SPM_VEN_PWR_CON 0x0230
+#define SPM_ISP_PWR_CON 0x0238
+#define SPM_DIS_PWR_CON 0x023c
+#define SPM_VEN2_PWR_CON 0x0298
+#define SPM_AUDIO_PWR_CON 0x029c
+#define SPM_MFG_2D_PWR_CON 0x02c0
+#define SPM_MFG_ASYNC_PWR_CON 0x02c4
+#define SPM_USB_PWR_CON 0x02cc
+
+#define SPM_PWR_STATUS 0x060c
+#define SPM_PWR_STATUS_2ND 0x0610
+
+#define PWR_RST_B_BIT BIT(0)
+#define PWR_ISO_BIT BIT(1)
+#define PWR_ON_BIT BIT(2)
+#define PWR_ON_2ND_BIT BIT(3)
+#define PWR_CLK_DIS_BIT BIT(4)
+
+#define PWR_STATUS_DISP BIT(3)
+#define PWR_STATUS_MFG BIT(4)
+#define PWR_STATUS_ISP BIT(5)
+#define PWR_STATUS_VDEC BIT(7)
+#define PWR_STATUS_VENC_LT BIT(20)
+#define PWR_STATUS_VENC BIT(21)
+#define PWR_STATUS_MFG_2D BIT(22)
+#define PWR_STATUS_MFG_ASYNC BIT(23)
+#define PWR_STATUS_AUDIO BIT(24)
+#define PWR_STATUS_USB BIT(25)
+
+struct scpsys_bus_prot_data {
+ u32 bus_prot_mask;
+ bool bus_prot_reg_update;
+};
+
+/**
+ * struct scpsys_domain_data - scp domain data for power on/off flow
+ * @sta_mask: The mask for power on/off status bit.
+ * @ctl_offs: The offset for main power control register.
+ * @sram_pdn_bits: The mask for sram power control bits.
+ * @sram_pdn_ack_bits: The mask for sram power control acked bits.
+ * @caps: The flag for active wake-up action.
+ * @bp_infracfg: bus protection for infracfg subsystem
+ */
+struct scpsys_domain_data {
+ u32 sta_mask;
+ int ctl_offs;
+ u32 sram_pdn_bits;
+ u32 sram_pdn_ack_bits;
+ u8 caps;
+ const struct scpsys_bus_prot_data bp_infracfg;
+};
+
+struct scpsys_domain {
+ struct generic_pm_domain genpd;
+ const struct scpsys_domain_data *data;
+ struct scpsys *scpsys;
+ int num_clks;
+ struct clk_bulk_data *clks;
+ struct regmap *infracfg;
+};
+
+struct scpsys_soc_data {
+ const struct scpsys_domain_data *domains;
+ int num_domains;
+ int pwr_sta_offs;
+ int pwr_sta2nd_offs;
+};
+
+struct scpsys {
+ struct device *dev;
+ struct regmap *base;
+ const struct scpsys_soc_data *soc_data;
+ struct genpd_onecell_data pd_data;
+ struct generic_pm_domain *domains[];
+};
+
+#define to_scpsys_domain(gpd) container_of(gpd, struct scpsys_domain, genpd)
+
+static int scpsys_domain_is_on(struct scpsys_domain *pd)
+{
+ struct scpsys *scpsys = pd->scpsys;
+ u32 status, status2;
+
+ regmap_read(scpsys->base, scpsys->soc_data->pwr_sta_offs, &status);
+ status &= pd->data->sta_mask;
+
+ regmap_read(scpsys->base, scpsys->soc_data->pwr_sta2nd_offs, &status2);
+ status2 &= pd->data->sta_mask;
+
+ /*
+ * A domain is on when both status bits are set. If only one is set
+ * return an error. This happens while powering up a domain
+ */
+
+ if (status && status2)
+ return true;
+ if (!status && !status2)
+ return false;
+
+ return -EINVAL;
+}
+
+static int scpsys_sram_enable(struct scpsys_domain *pd)
+{
+ u32 pdn_ack = pd->data->sram_pdn_ack_bits;
+ struct scpsys *scpsys = pd->scpsys;
+ u32 val;
+ int tmp;
+
+ regmap_read(scpsys->base, pd->data->ctl_offs, &val);
+ val &= ~pd->data->sram_pdn_bits;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ /* Either wait until SRAM_PDN_ACK all 1 or 0 */
+ return regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
+ (tmp & pdn_ack) == 0, MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+}
+
+static int scpsys_sram_disable(struct scpsys_domain *pd)
+{
+ u32 pdn_ack = pd->data->sram_pdn_ack_bits;
+ struct scpsys *scpsys = pd->scpsys;
+ u32 val;
+ int tmp;
+
+ regmap_read(scpsys->base, pd->data->ctl_offs, &val);
+ val |= pd->data->sram_pdn_bits;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ /* Either wait until SRAM_PDN_ACK all 1 or 0 */
+ return regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
+ (tmp & pdn_ack) == pdn_ack, MTK_POLL_DELAY_US,
+ MTK_POLL_TIMEOUT);
+}
+
+static int scpsys_bus_protect_enable(struct scpsys_domain *pd)
+{
+ const struct scpsys_bus_prot_data *bp_data = &pd->data->bp_infracfg;
+
+ if (!bp_data->bus_prot_mask)
+ return 0;
+
+ return mtk_infracfg_set_bus_protection(pd->infracfg, bp_data->bus_prot_mask,
+ bp_data->bus_prot_reg_update);
+}
+
+static int scpsys_bus_protect_disable(struct scpsys_domain *pd)
+{
+ const struct scpsys_bus_prot_data *bp_data = &pd->data->bp_infracfg;
+
+ if (!bp_data->bus_prot_mask)
+ return 0;
+
+ return mtk_infracfg_clear_bus_protection(pd->infracfg, bp_data->bus_prot_mask,
+ bp_data->bus_prot_reg_update);
+}
+
+static int scpsys_power_on(struct generic_pm_domain *genpd)
+{
+ struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
+ struct scpsys *scpsys = pd->scpsys;
+ int ret, tmp;
+ u32 val;
+
+ ret = clk_bulk_enable(pd->num_clks, pd->clks);
+ if (ret)
+ return ret;
+
+ /* subsys power on */
+ regmap_read(scpsys->base, pd->data->ctl_offs, &val);
+ val |= PWR_ON_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+ val |= PWR_ON_2ND_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ /* wait until PWR_ACK = 1 */
+ ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp > 0, MTK_POLL_DELAY_US,
+ MTK_POLL_TIMEOUT);
+ if (ret < 0)
+ goto err_pwr_ack;
+
+ val &= ~PWR_CLK_DIS_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ val &= ~PWR_ISO_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ val |= PWR_RST_B_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ ret = scpsys_sram_enable(pd);
+ if (ret < 0)
+ goto err_pwr_ack;
+
+ ret = scpsys_bus_protect_disable(pd);
+ if (ret < 0)
+ goto err_pwr_ack;
+
+ return 0;
+
+err_pwr_ack:
+ clk_bulk_disable(pd->num_clks, pd->clks);
+ return ret;
+}
+
+static int scpsys_power_off(struct generic_pm_domain *genpd)
+{
+ struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
+ struct scpsys *scpsys = pd->scpsys;
+ int ret, tmp;
+ u32 val;
+
+ ret = scpsys_bus_protect_enable(pd);
+ if (ret < 0)
+ return ret;
+
+ ret = scpsys_sram_disable(pd);
+ if (ret < 0)
+ return ret;
+
+ /* subsys power off */
+ regmap_read(scpsys->base, pd->data->ctl_offs, &val);
+ val |= PWR_ISO_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ val &= ~PWR_RST_B_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ val |= PWR_CLK_DIS_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ val &= ~PWR_ON_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ val &= ~PWR_ON_2ND_BIT;
+ regmap_write(scpsys->base, pd->data->ctl_offs, val);
+
+ /* wait until PWR_ACK = 0 */
+ ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp == 0, MTK_POLL_DELAY_US,
+ MTK_POLL_TIMEOUT);
+ if (ret < 0)
+ return ret;
+
+ clk_bulk_disable(pd->num_clks, pd->clks);
+
+ return 0;
+}
+
+static int scpsys_add_one_domain(struct scpsys *scpsys, struct device_node *node)
+{
+ const struct scpsys_domain_data *domain_data;
+ struct scpsys_domain *pd;
+ int i, ret;
+ u32 id;
+
+ ret = of_property_read_u32(node, "reg", &id);
+ if (ret) {
+ dev_err_probe(scpsys->dev, ret,
+ "%pOFn: failed to retrieve domain id from reg\n", node);
+ return -EINVAL;
+ }
+
+ if (id >= scpsys->soc_data->num_domains) {
+ dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
+ return -EINVAL;
+ }
+
+ domain_data = &scpsys->soc_data->domains[id];
+ if (!domain_data) {
+ dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: undefined domain id %d\n", node, id);
+ return -EINVAL;
+ }
+
+ pd = devm_kzalloc(scpsys->dev, sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ return -ENOMEM;
+
+ pd->data = domain_data;
+ pd->scpsys = scpsys;
+
+ pd->infracfg = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg");
+ if (IS_ERR(pd->infracfg))
+ pd->infracfg = NULL;
+
+ pd->num_clks = of_clk_get_parent_count(node);
+ if (pd->num_clks > 0) {
+ pd->clks = devm_kcalloc(scpsys->dev, pd->num_clks, sizeof(*pd->clks), GFP_KERNEL);
+ if (!pd->clks)
+ return -ENOMEM;
+ } else {
+ pd->num_clks = 0;
+ }
+
+ for (i = 0; i < pd->num_clks; i++) {
+ pd->clks[i].clk = of_clk_get(node, i);
+ if (IS_ERR(pd->clks[i].clk)) {
+ ret = PTR_ERR(pd->clks[i].clk);
+ dev_err_probe(scpsys->dev, ret, "%pOFn: failed to get clk at index %d\n",
+ node, i);
+ return ret;
+ }
+ }
+
+ ret = clk_bulk_prepare(pd->num_clks, pd->clks);
+ if (ret)
+ goto err_put_clocks;
+
+ /*
+ * Initially turn on all domains to make the domains usable
+ * with !CONFIG_PM and to get the hardware in sync with the
+ * software. The unused domains will be switched off during
+ * late_init time.
+ */
+ ret = scpsys_power_on(&pd->genpd);
+ if (ret < 0) {
+ dev_err_probe(scpsys->dev, ret, "failed to power on domain %pOFN\n", node);
+ goto err_unprepare_clocks;
+ }
+
+ pd->genpd.name = node->name;
+ pd->genpd.power_off = scpsys_power_off;
+ pd->genpd.power_on = scpsys_power_on;
+
+ pm_genpd_init(&pd->genpd, NULL, false);
+
+ scpsys->domains[id] = &pd->genpd;
+ return 0;
+
+err_unprepare_clocks:
+ clk_bulk_unprepare(pd->num_clks, pd->clks);
+err_put_clocks:
+ clk_bulk_put(pd->num_clks, pd->clks);
+ devm_kfree(scpsys->dev, pd->clks);
+ pd->num_clks = 0;
+ return ret;
+}
+
+static int scpsys_add_subdomain(struct scpsys *scpsys, struct device_node *parent)
+{
+ struct device_node *child;
+ struct generic_pm_domain *child_pd, *parent_pd;
+ int ret;
+
+ for_each_child_of_node(parent, child) {
+ u32 id;
+
+ ret = of_property_read_u32(parent, "reg", &id);
+ if (ret) {
+ dev_err_probe(scpsys->dev, ret,
+ "%pOFn: failed to get parent domain id\n", child);
+ goto err_put_node;
+ }
+ parent_pd = scpsys->pd_data.domains[id];
+
+ ret = scpsys_add_one_domain(scpsys, child);
+ if (ret)
+ goto err_put_node;
+
+ ret = of_property_read_u32(child, "reg", &id);
+ if (ret) {
+ dev_err_probe(scpsys->dev, ret,
+ "%pOFn: failed to get child domain id\n", child);
+ goto err_put_node;
+ }
+ child_pd = scpsys->pd_data.domains[id];
+
+ ret = pm_genpd_add_subdomain(parent_pd, child_pd);
+ if (ret) {
+ dev_err_probe(scpsys->dev, ret,
+ "failed to add %s subdomain to parent %s\n", child_pd->name,
+ parent_pd->name);
+ goto err_put_node;
+ } else {
+ dev_dbg(scpsys->dev, "%s add subdomain: %s\n", parent_pd->name,
+ child_pd->name);
+ }
+
+ /* recursive call to add all subdomains */
+ ret = scpsys_add_subdomain(scpsys, child);
+ if (ret)
+ goto err_put_node;
+ }
+
+ return 0;
+
+err_put_node:
+ of_node_put(child);
+ return ret;
+}
+
+static void scpsys_remove_one_domain(struct scpsys_domain *pd)
+{
+ int ret;
+
+ /*
+ * We're in the error cleanup already, so we only complain,
+ * but won't emit another error on top of the original one.
+ */
+ ret = pm_genpd_remove(&pd->genpd);
+ if (ret < 0)
+ dev_err(pd->scpsys->dev,
+ "failed to remove domain '%s' : %d - state may be inconsistent\n",
+ pd->genpd.name, ret);
+
+ scpsys_power_off(&pd->genpd);
+
+ clk_bulk_unprepare(pd->num_clks, pd->clks);
+ clk_bulk_put(pd->num_clks, pd->clks);
+ pd->num_clks = 0;
+}
+
+static void scpsys_domain_cleanup(struct scpsys *scpsys)
+{
+ struct generic_pm_domain *genpd;
+ struct scpsys_domain *pd;
+ int i;
+
+ for (i = scpsys->pd_data.num_domains - 1; i >= 0; i--) {
+ genpd = scpsys->pd_data.domains[i];
+ if (genpd) {
+ pd = to_scpsys_domain(genpd);
+ scpsys_remove_one_domain(pd);
+ }
+ }
+}
+
+/*
+ * MT8173 power domain support
+ */
+
+static const struct scpsys_domain_data scpsys_domain_data_mt8173[] = {
+ [MT8173_POWER_DOMAIN_VDEC] = {
+ .sta_mask = PWR_STATUS_VDEC,
+ .ctl_offs = SPM_VDE_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(12, 12),
+ },
+ [MT8173_POWER_DOMAIN_VENC] = {
+ .sta_mask = PWR_STATUS_VENC,
+ .ctl_offs = SPM_VEN_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(15, 12),
+ },
+ [MT8173_POWER_DOMAIN_ISP] = {
+ .sta_mask = PWR_STATUS_ISP,
+ .ctl_offs = SPM_ISP_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(13, 12),
+ },
+ [MT8173_POWER_DOMAIN_MM] = {
+ .sta_mask = PWR_STATUS_DISP,
+ .ctl_offs = SPM_DIS_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(12, 12),
+ .bp_infracfg = {
+ .bus_prot_reg_update = true,
+ .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MM_M0 |
+ MT8173_TOP_AXI_PROT_EN_MM_M1,
+ },
+ },
+ [MT8173_POWER_DOMAIN_VENC_LT] = {
+ .sta_mask = PWR_STATUS_VENC_LT,
+ .ctl_offs = SPM_VEN2_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(15, 12),
+ },
+ [MT8173_POWER_DOMAIN_AUDIO] = {
+ .sta_mask = PWR_STATUS_AUDIO,
+ .ctl_offs = SPM_AUDIO_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(15, 12),
+ },
+ [MT8173_POWER_DOMAIN_USB] = {
+ .sta_mask = PWR_STATUS_USB,
+ .ctl_offs = SPM_USB_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(15, 12),
+ .caps = MTK_SCPD_ACTIVE_WAKEUP,
+ },
+ [MT8173_POWER_DOMAIN_MFG_ASYNC] = {
+ .sta_mask = PWR_STATUS_MFG_ASYNC,
+ .ctl_offs = SPM_MFG_ASYNC_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = 0,
+ },
+ [MT8173_POWER_DOMAIN_MFG_2D] = {
+ .sta_mask = PWR_STATUS_MFG_2D,
+ .ctl_offs = SPM_MFG_2D_PWR_CON,
+ .sram_pdn_bits = GENMASK(11, 8),
+ .sram_pdn_ack_bits = GENMASK(13, 12),
+ },
+ [MT8173_POWER_DOMAIN_MFG] = {
+ .sta_mask = PWR_STATUS_MFG,
+ .ctl_offs = SPM_MFG_PWR_CON,
+ .sram_pdn_bits = GENMASK(13, 8),
+ .sram_pdn_ack_bits = GENMASK(21, 16),
+ .bp_infracfg = {
+ .bus_prot_reg_update = true,
+ .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MFG_S |
+ MT8173_TOP_AXI_PROT_EN_MFG_M0 |
+ MT8173_TOP_AXI_PROT_EN_MFG_M1 |
+ MT8173_TOP_AXI_PROT_EN_MFG_SNOOP_OUT,
+ },
+ },
+};
+
+static const struct scpsys_soc_data mt8173_scpsys_data = {
+ .domains = scpsys_domain_data_mt8173,
+ .num_domains = ARRAY_SIZE(scpsys_domain_data_mt8173),
+ .pwr_sta_offs = SPM_PWR_STATUS,
+ .pwr_sta2nd_offs = SPM_PWR_STATUS_2ND,
+};
+
+static const struct of_device_id scpsys_of_match[] = {
+ {
+ .compatible = "mediatek,mt8173-power-controller",
+ .data = &mt8173_scpsys_data,
+ },
+ { }
+};
+
+static int scpsys_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ const struct scpsys_soc_data *soc;
+ struct device_node *node;
+ struct device *parent;
+ struct scpsys *scpsys;
+ int ret;
+
+ soc = of_device_get_match_data(&pdev->dev);
+ if (!soc) {
+ dev_err(&pdev->dev, "no power controller data\n");
+ return -EINVAL;
+ }
+
+ scpsys = devm_kzalloc(dev, struct_size(scpsys, domains, soc->num_domains), GFP_KERNEL);
+ if (!scpsys)
+ return -ENOMEM;
+
+ scpsys->dev = dev;
+ scpsys->soc_data = soc;
+
+ scpsys->pd_data.domains = scpsys->domains;
+ scpsys->pd_data.num_domains = soc->num_domains;
+
+ parent = dev->parent;
+ if (!parent) {
+ dev_err(dev, "no parent for syscon devices\n");
+ return -ENODEV;
+ }
+
+ scpsys->base = syscon_node_to_regmap(parent->of_node);
+ if (IS_ERR(scpsys->base)) {
+ dev_err(dev, "no regmap available\n");
+ return PTR_ERR(scpsys->base);
+ }
+
+ ret = -ENODEV;
+ for_each_available_child_of_node(np, node) {
+ ret = scpsys_add_one_domain(scpsys, node);
+ if (ret) {
+ of_node_put(node);
+ goto err_cleanup_domains;
+ }
+
+ ret = scpsys_add_subdomain(scpsys, node);
+ if (ret) {
+ of_node_put(node);
+ goto err_cleanup_domains;
+ }
+ }
+
+ if (ret) {
+ dev_dbg(dev, "no power domains present\n");
+ return ret;
+ }
+
+ ret = of_genpd_add_provider_onecell(np, &scpsys->pd_data);
+ if (ret) {
+ dev_err(dev, "failed to add provider: %d\n", ret);
+ goto err_cleanup_domains;
+ }
+
+ return 0;
+
+err_cleanup_domains:
+ scpsys_domain_cleanup(scpsys);
+ return ret;
+}
+
+static struct platform_driver scpsys_pm_domain_driver = {
+ .probe = scpsys_probe,
+ .driver = {
+ .name = "mtk-power-controller",
+ .suppress_bind_attrs = true,
+ .of_match_table = scpsys_of_match,
+ },
+};
+builtin_platform_driver(scpsys_pm_domain_driver);
--
2.28.0


2020-10-05 01:41:30

by Nicolas Boichat

[permalink] [raw]
Subject: Re: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

On Fri, Oct 2, 2020 at 12:02 AM Enric Balletbo i Serra
<[email protected]> wrote:
>
> The System Control Processor System (SCPSYS) has several power management
> related tasks in the system. This driver implements support to handle
> the different power domains supported in order to meet high performance
> and low power requirements.
>
> Co-developed-by: Matthias Brugger <[email protected]>
> Signed-off-by: Matthias Brugger <[email protected]>
> Signed-off-by: Enric Balletbo i Serra <[email protected]>
> ---
>
> Changes in v2:
> - Get base address from parent syscon. We have now a scpsys syscon node
> and a child for the SPM (System Power Manager).
> - Use regmap API to acces de base address.
>
> drivers/soc/mediatek/Kconfig | 13 +
> drivers/soc/mediatek/Makefile | 1 +
> drivers/soc/mediatek/mtk-pm-domains.c | 628 ++++++++++++++++++++++++++
> 3 files changed, 642 insertions(+)
> create mode 100644 drivers/soc/mediatek/mtk-pm-domains.c
>
> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> index 59a56cd790ec..68d800f9e4a5 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -44,6 +44,19 @@ config MTK_SCPSYS
> Say yes here to add support for the MediaTek SCPSYS power domain
> driver.
>
> +config MTK_SCPSYS_PM_DOMAINS
> + bool "MediaTek SCPSYS generic power domain"
> + default ARCH_MEDIATEK
> + depends on PM
> + depends on MTK_INFRACFG
> + select PM_GENERIC_DOMAINS
> + select REGMAP
> + help
> + Say y here to enable power domain support.
> + In order to meet high performance and low power requirements, the System
> + Control Processor System (SCPSYS) has several power management related
> + tasks in the system.
> +
> config MTK_MMSYS
> bool "MediaTek MMSYS Support"
> default ARCH_MEDIATEK
> diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
> index 01f9f873634a..1e60fb4f89d4 100644
> --- a/drivers/soc/mediatek/Makefile
> +++ b/drivers/soc/mediatek/Makefile
> @@ -3,4 +3,5 @@ obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
> obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
> obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
> obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
> +obj-$(CONFIG_MTK_SCPSYS_PM_DOMAINS) += mtk-pm-domains.o
> obj-$(CONFIG_MTK_MMSYS) += mtk-mmsys.o
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
> new file mode 100644
> index 000000000000..68886bf437f9
> --- /dev/null
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -0,0 +1,628 @@
> [snip]
> +
> +static int scpsys_domain_is_on(struct scpsys_domain *pd)
> +{
> + struct scpsys *scpsys = pd->scpsys;
> + u32 status, status2;
> +
> + regmap_read(scpsys->base, scpsys->soc_data->pwr_sta_offs, &status);
> + status &= pd->data->sta_mask;
> +
> + regmap_read(scpsys->base, scpsys->soc_data->pwr_sta2nd_offs, &status2);
> + status2 &= pd->data->sta_mask;
> +
> + /*
> + * A domain is on when both status bits are set. If only one is set
> + * return an error. This happens while powering up a domain
> + */
> +
> + if (status && status2)
> + return true;
> + if (!status && !status2)
> + return false;
> +
> + return -EINVAL;


Why do you care? It seems like all you ever do with this is check if
the domain is powered on, so it seems like you could just
return (status && status2); ?

> +}
> +
> +static int scpsys_sram_enable(struct scpsys_domain *pd)
> +{
> + u32 pdn_ack = pd->data->sram_pdn_ack_bits;
> + struct scpsys *scpsys = pd->scpsys;
> + u32 val;
> + int tmp;

regmap_read_poll_timeout => regmap_read technically takes a `unsigned
int *` parameter, so this should probably be unsigned too (or... just
reuse val?)

> +
> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
> + val &= ~pd->data->sram_pdn_bits;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);

Replace with regmap_update_bits?

> +
> + /* Either wait until SRAM_PDN_ACK all 1 or 0 */
> + return regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
> + (tmp & pdn_ack) == 0, MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> +}
> +
> +static int scpsys_sram_disable(struct scpsys_domain *pd)
> +{
> + u32 pdn_ack = pd->data->sram_pdn_ack_bits;
> + struct scpsys *scpsys = pd->scpsys;
> + u32 val;
> + int tmp;
> +
> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
> + val |= pd->data->sram_pdn_bits;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + /* Either wait until SRAM_PDN_ACK all 1 or 0 */
> + return regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
> + (tmp & pdn_ack) == pdn_ack, MTK_POLL_DELAY_US,
> + MTK_POLL_TIMEOUT);
> +}
> +
> +static int scpsys_bus_protect_enable(struct scpsys_domain *pd)
> +{
> + const struct scpsys_bus_prot_data *bp_data = &pd->data->bp_infracfg;
> +
> + if (!bp_data->bus_prot_mask)
> + return 0;
> +
> + return mtk_infracfg_set_bus_protection(pd->infracfg, bp_data->bus_prot_mask,
> + bp_data->bus_prot_reg_update);
> +}
> +
> +static int scpsys_bus_protect_disable(struct scpsys_domain *pd)
> +{
> + const struct scpsys_bus_prot_data *bp_data = &pd->data->bp_infracfg;
> +
> + if (!bp_data->bus_prot_mask)
> + return 0;
> +
> + return mtk_infracfg_clear_bus_protection(pd->infracfg, bp_data->bus_prot_mask,
> + bp_data->bus_prot_reg_update);
> +}
> +
> +static int scpsys_power_on(struct generic_pm_domain *genpd)
> +{
> + struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
> + struct scpsys *scpsys = pd->scpsys;
> + int ret, tmp;
> + u32 val;
> +
> + ret = clk_bulk_enable(pd->num_clks, pd->clks);
> + if (ret)
> + return ret;
> +
> + /* subsys power on */
> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
> + val |= PWR_ON_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> + val |= PWR_ON_2ND_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + /* wait until PWR_ACK = 1 */
> + ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp > 0, MTK_POLL_DELAY_US,
> + MTK_POLL_TIMEOUT);
> + if (ret < 0)
> + goto err_pwr_ack;
> +
> + val &= ~PWR_CLK_DIS_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + val &= ~PWR_ISO_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + val |= PWR_RST_B_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + ret = scpsys_sram_enable(pd);
> + if (ret < 0)
> + goto err_pwr_ack;
> +
> + ret = scpsys_bus_protect_disable(pd);
> + if (ret < 0)
> + goto err_pwr_ack;
> +
> + return 0;
> +
> +err_pwr_ack:
> + clk_bulk_disable(pd->num_clks, pd->clks);
> + return ret;
> +}
> +
> +static int scpsys_power_off(struct generic_pm_domain *genpd)
> +{
> + struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
> + struct scpsys *scpsys = pd->scpsys;
> + int ret, tmp;
> + u32 val;
> +
> + ret = scpsys_bus_protect_enable(pd);
> + if (ret < 0)
> + return ret;
> +
> + ret = scpsys_sram_disable(pd);
> + if (ret < 0)
> + return ret;
> +
> + /* subsys power off */
> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
> + val |= PWR_ISO_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + val &= ~PWR_RST_B_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + val |= PWR_CLK_DIS_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + val &= ~PWR_ON_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + val &= ~PWR_ON_2ND_BIT;
> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
> +
> + /* wait until PWR_ACK = 0 */
> + ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp == 0, MTK_POLL_DELAY_US,
> + MTK_POLL_TIMEOUT);
> + if (ret < 0)
> + return ret;
> +
> + clk_bulk_disable(pd->num_clks, pd->clks);
> +
> + return 0;
> +}
> +
> +static int scpsys_add_one_domain(struct scpsys *scpsys, struct device_node *node)
> +{
> + const struct scpsys_domain_data *domain_data;
> + struct scpsys_domain *pd;
> + int i, ret;
> + u32 id;
> +
> + ret = of_property_read_u32(node, "reg", &id);
> + if (ret) {
> + dev_err_probe(scpsys->dev, ret,
> + "%pOFn: failed to retrieve domain id from reg\n", node);
> + return -EINVAL;
> + }
> +
> + if (id >= scpsys->soc_data->num_domains) {
> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
> + return -EINVAL;
> + }
> +
> + domain_data = &scpsys->soc_data->domains[id];
> + if (!domain_data) {

Is that even possible at all? I mean, even if
scpsys->soc_data->domains is NULL, as long as id != 0, this will no
happen.

> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: undefined domain id %d\n", node, id);
> + return -EINVAL;
> + }
> +
> + pd = devm_kzalloc(scpsys->dev, sizeof(*pd), GFP_KERNEL);
> + if (!pd)
> + return -ENOMEM;
> +
> + pd->data = domain_data;
> + pd->scpsys = scpsys;
> +
> + pd->infracfg = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg");
> + if (IS_ERR(pd->infracfg))
> + pd->infracfg = NULL;
> +
> + pd->num_clks = of_clk_get_parent_count(node);
> + if (pd->num_clks > 0) {
> + pd->clks = devm_kcalloc(scpsys->dev, pd->num_clks, sizeof(*pd->clks), GFP_KERNEL);
> + if (!pd->clks)
> + return -ENOMEM;
> + } else {
> + pd->num_clks = 0;
> + }

pd->num_clks < 0 can't happen so you can drop this.

> +
> + for (i = 0; i < pd->num_clks; i++) {
> + pd->clks[i].clk = of_clk_get(node, i);
> + if (IS_ERR(pd->clks[i].clk)) {
> + ret = PTR_ERR(pd->clks[i].clk);
> + dev_err_probe(scpsys->dev, ret, "%pOFn: failed to get clk at index %d\n",
> + node, i);
> + return ret;
> + }
> + }
> +
> + ret = clk_bulk_prepare(pd->num_clks, pd->clks);
> + if (ret)
> + goto err_put_clocks;
> +
> + /*
> + * Initially turn on all domains to make the domains usable
> + * with !CONFIG_PM and to get the hardware in sync with the
> + * software. The unused domains will be switched off during
> + * late_init time.
> + */
> + ret = scpsys_power_on(&pd->genpd);
> + if (ret < 0) {
> + dev_err_probe(scpsys->dev, ret, "failed to power on domain %pOFN\n", node);
> + goto err_unprepare_clocks;
> + }
> +
> + pd->genpd.name = node->name;
> + pd->genpd.power_off = scpsys_power_off;
> + pd->genpd.power_on = scpsys_power_on;
> +
> + pm_genpd_init(&pd->genpd, NULL, false);
> +
> + scpsys->domains[id] = &pd->genpd;

Do we want to add some logic to make sure scpsys->domains[id] == NULL
before this? (to make sure we don't accidentally probe 2 domains with
the same id, which I guess could happen with some incorrect
devicetree)

> + return 0;
> +
> +err_unprepare_clocks:
> + clk_bulk_unprepare(pd->num_clks, pd->clks);
> +err_put_clocks:
> + clk_bulk_put(pd->num_clks, pd->clks);

> + devm_kfree(scpsys->dev, pd->clks);
> + pd->num_clks = 0;

Why do you need these 2 lines? Can't you just let the core free the
devm_ allocated data?

> + return ret;
> +}
> +
> +static int scpsys_add_subdomain(struct scpsys *scpsys, struct device_node *parent)
> +{
> + struct device_node *child;
> + struct generic_pm_domain *child_pd, *parent_pd;
> + int ret;
> +
> + for_each_child_of_node(parent, child) {
> + u32 id;
> +
> + ret = of_property_read_u32(parent, "reg", &id);
> + if (ret) {
> + dev_err_probe(scpsys->dev, ret,
> + "%pOFn: failed to get parent domain id\n", child);
> + goto err_put_node;
> + }
> + parent_pd = scpsys->pd_data.domains[id];

No bounds check on id here? Also, wondering if you want to move the
logic, including bounds check, to a small function (since it's
repeated 3 times now, but I think that can be reduced to 2).

> +
> + ret = scpsys_add_one_domain(scpsys, child);
> + if (ret)
> + goto err_put_node;
> +
> + ret = of_property_read_u32(child, "reg", &id);
> + if (ret) {
> + dev_err_probe(scpsys->dev, ret,
> + "%pOFn: failed to get child domain id\n", child);
> + goto err_put_node;
> + }
> + child_pd = scpsys->pd_data.domains[id];

You already obtained the child_pd in scpsys_add_one_domain... Can you
have scpsys_add_one_domain return `child_pd` as a pointer (or a
PTR_ERR)?

> +
> + ret = pm_genpd_add_subdomain(parent_pd, child_pd);
> + if (ret) {
> + dev_err_probe(scpsys->dev, ret,
> + "failed to add %s subdomain to parent %s\n", child_pd->name,
> + parent_pd->name);
> + goto err_put_node;
> + } else {
> + dev_dbg(scpsys->dev, "%s add subdomain: %s\n", parent_pd->name,
> + child_pd->name);
> + }
> +
> + /* recursive call to add all subdomains */
> + ret = scpsys_add_subdomain(scpsys, child);
> + if (ret)
> + goto err_put_node;
> + }
> +
> + return 0;
> +
> +err_put_node:
> + of_node_put(child);
> + return ret;
> +}
> +
> +static void scpsys_remove_one_domain(struct scpsys_domain *pd)
> +{
> + int ret;
> +
> + /*
> + * We're in the error cleanup already, so we only complain,
> + * but won't emit another error on top of the original one.
> + */
> + ret = pm_genpd_remove(&pd->genpd);
> + if (ret < 0)
> + dev_err(pd->scpsys->dev,
> + "failed to remove domain '%s' : %d - state may be inconsistent\n",
> + pd->genpd.name, ret);
> +
> + scpsys_power_off(&pd->genpd);
> +
> + clk_bulk_unprepare(pd->num_clks, pd->clks);
> + clk_bulk_put(pd->num_clks, pd->clks);

> + pd->num_clks = 0;

What's the point of setting num_clks to 0?

> +}
> +
> +static void scpsys_domain_cleanup(struct scpsys *scpsys)
> +{
> + struct generic_pm_domain *genpd;
> + struct scpsys_domain *pd;
> + int i;
> +
> + for (i = scpsys->pd_data.num_domains - 1; i >= 0; i--) {
> + genpd = scpsys->pd_data.domains[i];
> + if (genpd) {
> + pd = to_scpsys_domain(genpd);
> + scpsys_remove_one_domain(pd);
> + }
> + }
> +}
> [snip]

2020-10-26 18:57:09

by Enric Balletbo i Serra

[permalink] [raw]
Subject: Re: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

Hi Nicolas,

Many thanks for looking at this.

On 5/10/20 3:39, Nicolas Boichat wrote:
> On Fri, Oct 2, 2020 at 12:02 AM Enric Balletbo i Serra
> <[email protected]> wrote:
>>
>> The System Control Processor System (SCPSYS) has several power management
>> related tasks in the system. This driver implements support to handle
>> the different power domains supported in order to meet high performance
>> and low power requirements.
>>
>> Co-developed-by: Matthias Brugger <[email protected]>
>> Signed-off-by: Matthias Brugger <[email protected]>
>> Signed-off-by: Enric Balletbo i Serra <[email protected]>
>> ---
>>
>> Changes in v2:
>> - Get base address from parent syscon. We have now a scpsys syscon node
>> and a child for the SPM (System Power Manager).
>> - Use regmap API to acces de base address.
>>
>> drivers/soc/mediatek/Kconfig | 13 +
>> drivers/soc/mediatek/Makefile | 1 +
>> drivers/soc/mediatek/mtk-pm-domains.c | 628 ++++++++++++++++++++++++++
>> 3 files changed, 642 insertions(+)
>> create mode 100644 drivers/soc/mediatek/mtk-pm-domains.c
>>
>> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
>> index 59a56cd790ec..68d800f9e4a5 100644
>> --- a/drivers/soc/mediatek/Kconfig
>> +++ b/drivers/soc/mediatek/Kconfig
>> @@ -44,6 +44,19 @@ config MTK_SCPSYS
>> Say yes here to add support for the MediaTek SCPSYS power domain
>> driver.
>>
>> +config MTK_SCPSYS_PM_DOMAINS
>> + bool "MediaTek SCPSYS generic power domain"
>> + default ARCH_MEDIATEK
>> + depends on PM
>> + depends on MTK_INFRACFG
>> + select PM_GENERIC_DOMAINS
>> + select REGMAP
>> + help
>> + Say y here to enable power domain support.
>> + In order to meet high performance and low power requirements, the System
>> + Control Processor System (SCPSYS) has several power management related
>> + tasks in the system.
>> +
>> config MTK_MMSYS
>> bool "MediaTek MMSYS Support"
>> default ARCH_MEDIATEK
>> diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
>> index 01f9f873634a..1e60fb4f89d4 100644
>> --- a/drivers/soc/mediatek/Makefile
>> +++ b/drivers/soc/mediatek/Makefile
>> @@ -3,4 +3,5 @@ obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
>> obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
>> obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
>> obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
>> +obj-$(CONFIG_MTK_SCPSYS_PM_DOMAINS) += mtk-pm-domains.o
>> obj-$(CONFIG_MTK_MMSYS) += mtk-mmsys.o
>> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
>> new file mode 100644
>> index 000000000000..68886bf437f9
>> --- /dev/null
>> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
>> @@ -0,0 +1,628 @@
>> [snip]
>> +
>> +static int scpsys_domain_is_on(struct scpsys_domain *pd)
>> +{
>> + struct scpsys *scpsys = pd->scpsys;
>> + u32 status, status2;
>> +
>> + regmap_read(scpsys->base, scpsys->soc_data->pwr_sta_offs, &status);
>> + status &= pd->data->sta_mask;
>> +
>> + regmap_read(scpsys->base, scpsys->soc_data->pwr_sta2nd_offs, &status2);
>> + status2 &= pd->data->sta_mask;
>> +
>> + /*
>> + * A domain is on when both status bits are set. If only one is set
>> + * return an error. This happens while powering up a domain
>> + */
>> +
>> + if (status && status2)
>> + return true;
>> + if (!status && !status2)
>> + return false;
>> +
>> + return -EINVAL;
>
>
> Why do you care? It seems like all you ever do with this is check if
> the domain is powered on, so it seems like you could just
> return (status && status2); ?
>

Changed in v3


>> +}
>> +
>> +static int scpsys_sram_enable(struct scpsys_domain *pd)
>> +{
>> + u32 pdn_ack = pd->data->sram_pdn_ack_bits;
>> + struct scpsys *scpsys = pd->scpsys;
>> + u32 val;
>> + int tmp;
>
> regmap_read_poll_timeout => regmap_read technically takes a `unsigned
> int *` parameter, so this should probably be unsigned too (or... just
> reuse val?)
>

Changed in v3

>> +
>> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
>> + val &= ~pd->data->sram_pdn_bits;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>
> Replace with regmap_update_bits?
>

Right, I'll replace here and in the other places where is possible.

>> +
>> + /* Either wait until SRAM_PDN_ACK all 1 or 0 */
>> + return regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
>> + (tmp & pdn_ack) == 0, MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
>> +}
>> +
>> +static int scpsys_sram_disable(struct scpsys_domain *pd)
>> +{
>> + u32 pdn_ack = pd->data->sram_pdn_ack_bits;
>> + struct scpsys *scpsys = pd->scpsys;
>> + u32 val;
>> + int tmp;
>> +
>> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
>> + val |= pd->data->sram_pdn_bits;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + /* Either wait until SRAM_PDN_ACK all 1 or 0 */
>> + return regmap_read_poll_timeout(scpsys->base, pd->data->ctl_offs, tmp,
>> + (tmp & pdn_ack) == pdn_ack, MTK_POLL_DELAY_US,
>> + MTK_POLL_TIMEOUT);
>> +}
>> +
>> +static int scpsys_bus_protect_enable(struct scpsys_domain *pd)
>> +{
>> + const struct scpsys_bus_prot_data *bp_data = &pd->data->bp_infracfg;
>> +
>> + if (!bp_data->bus_prot_mask)
>> + return 0;
>> +
>> + return mtk_infracfg_set_bus_protection(pd->infracfg, bp_data->bus_prot_mask,
>> + bp_data->bus_prot_reg_update);
>> +}
>> +
>> +static int scpsys_bus_protect_disable(struct scpsys_domain *pd)
>> +{
>> + const struct scpsys_bus_prot_data *bp_data = &pd->data->bp_infracfg;
>> +
>> + if (!bp_data->bus_prot_mask)
>> + return 0;
>> +
>> + return mtk_infracfg_clear_bus_protection(pd->infracfg, bp_data->bus_prot_mask,
>> + bp_data->bus_prot_reg_update);
>> +}
>> +
>> +static int scpsys_power_on(struct generic_pm_domain *genpd)
>> +{
>> + struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
>> + struct scpsys *scpsys = pd->scpsys;
>> + int ret, tmp;
>> + u32 val;
>> +
>> + ret = clk_bulk_enable(pd->num_clks, pd->clks);
>> + if (ret)
>> + return ret;
>> +
>> + /* subsys power on */
>> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
>> + val |= PWR_ON_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> + val |= PWR_ON_2ND_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + /* wait until PWR_ACK = 1 */
>> + ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp > 0, MTK_POLL_DELAY_US,
>> + MTK_POLL_TIMEOUT);
>> + if (ret < 0)
>> + goto err_pwr_ack;
>> +
>> + val &= ~PWR_CLK_DIS_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + val &= ~PWR_ISO_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + val |= PWR_RST_B_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + ret = scpsys_sram_enable(pd);
>> + if (ret < 0)
>> + goto err_pwr_ack;
>> +
>> + ret = scpsys_bus_protect_disable(pd);
>> + if (ret < 0)
>> + goto err_pwr_ack;
>> +
>> + return 0;
>> +
>> +err_pwr_ack:
>> + clk_bulk_disable(pd->num_clks, pd->clks);
>> + return ret;
>> +}
>> +
>> +static int scpsys_power_off(struct generic_pm_domain *genpd)
>> +{
>> + struct scpsys_domain *pd = container_of(genpd, struct scpsys_domain, genpd);
>> + struct scpsys *scpsys = pd->scpsys;
>> + int ret, tmp;
>> + u32 val;
>> +
>> + ret = scpsys_bus_protect_enable(pd);
>> + if (ret < 0)
>> + return ret;
>> +
>> + ret = scpsys_sram_disable(pd);
>> + if (ret < 0)
>> + return ret;
>> +
>> + /* subsys power off */
>> + regmap_read(scpsys->base, pd->data->ctl_offs, &val);
>> + val |= PWR_ISO_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + val &= ~PWR_RST_B_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + val |= PWR_CLK_DIS_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + val &= ~PWR_ON_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + val &= ~PWR_ON_2ND_BIT;
>> + regmap_write(scpsys->base, pd->data->ctl_offs, val);
>> +
>> + /* wait until PWR_ACK = 0 */
>> + ret = readx_poll_timeout(scpsys_domain_is_on, pd, tmp, tmp == 0, MTK_POLL_DELAY_US,
>> + MTK_POLL_TIMEOUT);
>> + if (ret < 0)
>> + return ret;
>> +
>> + clk_bulk_disable(pd->num_clks, pd->clks);
>> +
>> + return 0;
>> +}
>> +
>> +static int scpsys_add_one_domain(struct scpsys *scpsys, struct device_node *node)
>> +{
>> + const struct scpsys_domain_data *domain_data;
>> + struct scpsys_domain *pd;
>> + int i, ret;
>> + u32 id;
>> +
>> + ret = of_property_read_u32(node, "reg", &id);
>> + if (ret) {
>> + dev_err_probe(scpsys->dev, ret,
>> + "%pOFn: failed to retrieve domain id from reg\n", node);
>> + return -EINVAL;
>> + }
>> +
>> + if (id >= scpsys->soc_data->num_domains) {
>> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
>> + return -EINVAL;
>> + }
>> +
>> + domain_data = &scpsys->soc_data->domains[id];
>> + if (!domain_data) {
>
> Is that even possible at all? I mean, even if
> scpsys->soc_data->domains is NULL, as long as id != 0, this will no
> happen.
>

I think could happen with a bad DT definition. I.e if for the definition of the
MT8173 domains you use a wrong value for the reg property, a value that is not
present in the SoC data. It is unlikely if you use the defines but could happen
if you hardcore the value. We cannot check this with the DT json-schema.

>> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: undefined domain id %d\n", node, id);
>> + return -EINVAL;
>> + }
>> +
>> + pd = devm_kzalloc(scpsys->dev, sizeof(*pd), GFP_KERNEL);
>> + if (!pd)
>> + return -ENOMEM;
>> +
>> + pd->data = domain_data;
>> + pd->scpsys = scpsys;
>> +
>> + pd->infracfg = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg");
>> + if (IS_ERR(pd->infracfg))
>> + pd->infracfg = NULL;
>> +
>> + pd->num_clks = of_clk_get_parent_count(node);
>> + if (pd->num_clks > 0) {
>> + pd->clks = devm_kcalloc(scpsys->dev, pd->num_clks, sizeof(*pd->clks), GFP_KERNEL);
>> + if (!pd->clks)
>> + return -ENOMEM;
>> + } else {
>> + pd->num_clks = 0;
>> + }
>
> pd->num_clks < 0 can't happen so you can drop this.
>

Right, removed in the next version.

>> +
>> + for (i = 0; i < pd->num_clks; i++) {
>> + pd->clks[i].clk = of_clk_get(node, i);
>> + if (IS_ERR(pd->clks[i].clk)) {
>> + ret = PTR_ERR(pd->clks[i].clk);
>> + dev_err_probe(scpsys->dev, ret, "%pOFn: failed to get clk at index %d\n",
>> + node, i);
>> + return ret;
>> + }
>> + }
>> +
>> + ret = clk_bulk_prepare(pd->num_clks, pd->clks);
>> + if (ret)
>> + goto err_put_clocks;
>> +
>> + /*
>> + * Initially turn on all domains to make the domains usable
>> + * with !CONFIG_PM and to get the hardware in sync with the
>> + * software. The unused domains will be switched off during
>> + * late_init time.
>> + */
>> + ret = scpsys_power_on(&pd->genpd);
>> + if (ret < 0) {
>> + dev_err_probe(scpsys->dev, ret, "failed to power on domain %pOFN\n", node);
>> + goto err_unprepare_clocks;
>> + }
>> +
>> + pd->genpd.name = node->name;
>> + pd->genpd.power_off = scpsys_power_off;
>> + pd->genpd.power_on = scpsys_power_on;
>> +
>> + pm_genpd_init(&pd->genpd, NULL, false);
>> +
>> + scpsys->domains[id] = &pd->genpd;
>
> Do we want to add some logic to make sure scpsys->domains[id] == NULL
> before this? (to make sure we don't accidentally probe 2 domains with
> the same id, which I guess could happen with some incorrect
> devicetree)
>

Good idea, I'll do in next version.



>> + return 0;
>> +
>> +err_unprepare_clocks:
>> + clk_bulk_unprepare(pd->num_clks, pd->clks);
>> +err_put_clocks:
>> + clk_bulk_put(pd->num_clks, pd->clks);
>
>> + devm_kfree(scpsys->dev, pd->clks);
>> + pd->num_clks = 0;
>
> Why do you need these 2 lines? Can't you just let the core free the
> devm_ allocated data?
>

Right, this is in the probe path, so no need to free the resources, the core
will do it.

>> + return ret;
>> +}
>> +
>> +static int scpsys_add_subdomain(struct scpsys *scpsys, struct device_node *parent)
>> +{
>> + struct device_node *child;
>> + struct generic_pm_domain *child_pd, *parent_pd;
>> + int ret;
>> +
>> + for_each_child_of_node(parent, child) {
>> + u32 id;
>> +
>> + ret = of_property_read_u32(parent, "reg", &id);
>> + if (ret) {
>> + dev_err_probe(scpsys->dev, ret,
>> + "%pOFn: failed to get parent domain id\n", child);
>> + goto err_put_node;
>> + }
>> + parent_pd = scpsys->pd_data.domains[id];
>
> No bounds check on id here? Also, wondering if you want to move the
> logic, including bounds check, to a small function (since it's
> repeated 3 times now, but I think that can be reduced to 2).
>

Done in the next version.

>> +
>> + ret = scpsys_add_one_domain(scpsys, child);
>> + if (ret)
>> + goto err_put_node;
>> +
>> + ret = of_property_read_u32(child, "reg", &id);
>> + if (ret) {
>> + dev_err_probe(scpsys->dev, ret,
>> + "%pOFn: failed to get child domain id\n", child);
>> + goto err_put_node;
>> + }
>> + child_pd = scpsys->pd_data.domains[id];
>
> You already obtained the child_pd in scpsys_add_one_domain... Can you
> have scpsys_add_one_domain return `child_pd` as a pointer (or a
> PTR_ERR)?
>

Good idea, done in next version.


>> +
>> + ret = pm_genpd_add_subdomain(parent_pd, child_pd);
>> + if (ret) {
>> + dev_err_probe(scpsys->dev, ret,
>> + "failed to add %s subdomain to parent %s\n", child_pd->name,
>> + parent_pd->name);
>> + goto err_put_node;
>> + } else {
>> + dev_dbg(scpsys->dev, "%s add subdomain: %s\n", parent_pd->name,
>> + child_pd->name);
>> + }
>> +
>> + /* recursive call to add all subdomains */
>> + ret = scpsys_add_subdomain(scpsys, child);
>> + if (ret)
>> + goto err_put_node;
>> + }
>> +
>> + return 0;
>> +
>> +err_put_node:
>> + of_node_put(child);
>> + return ret;
>> +}
>> +
>> +static void scpsys_remove_one_domain(struct scpsys_domain *pd)
>> +{
>> + int ret;
>> +
>> + /*
>> + * We're in the error cleanup already, so we only complain,
>> + * but won't emit another error on top of the original one.
>> + */
>> + ret = pm_genpd_remove(&pd->genpd);
>> + if (ret < 0)
>> + dev_err(pd->scpsys->dev,
>> + "failed to remove domain '%s' : %d - state may be inconsistent\n",
>> + pd->genpd.name, ret);
>> +
>> + scpsys_power_off(&pd->genpd);
>> +
>> + clk_bulk_unprepare(pd->num_clks, pd->clks);
>> + clk_bulk_put(pd->num_clks, pd->clks);
>
>> + pd->num_clks = 0;
>
> What's the point of setting num_clks to 0?
>

No really needed, no.

>> +}
>> +
>> +static void scpsys_domain_cleanup(struct scpsys *scpsys)
>> +{
>> + struct generic_pm_domain *genpd;
>> + struct scpsys_domain *pd;
>> + int i;
>> +
>> + for (i = scpsys->pd_data.num_domains - 1; i >= 0; i--) {
>> + genpd = scpsys->pd_data.domains[i];
>> + if (genpd) {
>> + pd = to_scpsys_domain(genpd);
>> + scpsys_remove_one_domain(pd);
>> + }
>> + }
>> +}
>> [snip]

2020-10-27 00:32:31

by Nicolas Boichat

[permalink] [raw]
Subject: Re: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

Hi Enric,

On Mon, Oct 26, 2020 at 11:17 PM Enric Balletbo i Serra
<[email protected]> wrote:
>
> Hi Nicolas,
>
> Many thanks for looking at this.

Thanks to you ,-)

[snip]
> >> + if (id >= scpsys->soc_data->num_domains) {
> >> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
> >> + return -EINVAL;
> >> + }
> >> +
> >> + domain_data = &scpsys->soc_data->domains[id];
> >> + if (!domain_data) {
> >
> > Is that even possible at all? I mean, even if
> > scpsys->soc_data->domains is NULL, as long as id != 0, this will no
> > happen.
> >
>
> I think could happen with a bad DT definition. I.e if for the definition of the
> MT8173 domains you use a wrong value for the reg property, a value that is not
> present in the SoC data. It is unlikely if you use the defines but could happen
> if you hardcore the value. We cannot check this with the DT json-schema.

I wasn't clear in my explanation, and looking further there is more
that looks wrong.

This expression &scpsys->soc_data->domains[id] is a pointer to element
"id" of the array domains. So if you convert to integer arithmetic,
it'll be something like `(long)scpsys->soc_data->domains +
(sizeof(struct generic_pm_domain *)) * id`. The only way this can be
NULL is if scpsys->soc_data->domains pointer is NULL, which, actually,
can't really happen as it's the 5th element of a struct scpsys
structure `(long)scpsys->soc_data + offset_of(domains, struct scpsys)
+ (sizeof(struct generic_pm_domain *)) * id`.

I think what you mean is either:
domain_data = &scpsys->soc_data->domains[id];
if (!*domain_data)
[but then domain_data type should be `struct generic_pm_domain **`?
Does your code compile with warnings enabled?]
or:
domain_data = scpsys->soc_data->domains[id];
if (!domain_data)
[then the test makes sense]

[snip]

2020-10-27 17:09:47

by Enric Balletbo i Serra

[permalink] [raw]
Subject: Re: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

Hi Nicolas,

On 27/10/20 1:19, Nicolas Boichat wrote:
> Hi Enric,
>
> On Mon, Oct 26, 2020 at 11:17 PM Enric Balletbo i Serra
> <[email protected]> wrote:
>>
>> Hi Nicolas,
>>
>> Many thanks for looking at this.
>
> Thanks to you ,-)
>
> [snip]
>>>> + if (id >= scpsys->soc_data->num_domains) {
>>>> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + domain_data = &scpsys->soc_data->domains[id];
>>>> + if (!domain_data) {
>>>
>>> Is that even possible at all? I mean, even if
>>> scpsys->soc_data->domains is NULL, as long as id != 0, this will no
>>> happen.
>>>
>>
>> I think could happen with a bad DT definition. I.e if for the definition of the
>> MT8173 domains you use a wrong value for the reg property, a value that is not
>> present in the SoC data. It is unlikely if you use the defines but could happen
>> if you hardcore the value. We cannot check this with the DT json-schema.
>
> I wasn't clear in my explanation, and looking further there is more
> that looks wrong.
>
> This expression &scpsys->soc_data->domains[id] is a pointer to element
> "id" of the array domains. So if you convert to integer arithmetic,
> it'll be something like `(long)scpsys->soc_data->domains +
> (sizeof(struct generic_pm_domain *)) * id`. The only way this can be
> NULL is if scpsys->soc_data->domains pointer is NULL, which, actually,
> can't really happen as it's the 5th element of a struct scpsys
> structure `(long)scpsys->soc_data + offset_of(domains, struct scpsys)
> + (sizeof(struct generic_pm_domain *)) * id`.
>
> I think what you mean is either:
> domain_data = &scpsys->soc_data->domains[id];
> if (!*domain_data)
> [but then domain_data type should be `struct generic_pm_domain **`?

I think you're confusing the field `struct generic_pm_domain *domains[]`from the
`struct scpsys` with `const struct scpsys_domain_data *domains` from `struct
scpsys_soc_data`. My bad they have the same name, I should probably rename the
second one as domain_info or domain_data to avoid that confusion.


diff --git a/drivers/soc/mediatek/mtk-pm-domains.h
b/drivers/soc/mediatek/mtk-pm-domains.h
index 7c8efcb3cef2..6ff095db8a27 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.h
+++ b/drivers/soc/mediatek/mtk-pm-domains.h
@@ -56,7 +56,7 @@ struct scpsys_domain_data {
};

struct scpsys_soc_data {
- const struct scpsys_domain_data *domains;
+ const struct scpsys_domain_data *domain_data;
int num_domains;
int pwr_sta_offs;
int pwr_sta2nd_offs;

---

struct scpsys {
...
const struct scpsys_soc_data *soc_data;
...
struct generic_pm_domain *domains[];
}


domain_data = &scpsys->soc_data->domain_data[id];
if (!domain_data)

Thanks,
Enric


> Does your code compile with warnings enabled?]
> or:
> domain_data = scpsys->soc_data->domains[id];
> if (!domain_data)
> [then the test makes sense]
>
> [snip]
>

2020-10-29 08:36:32

by Nicolas Boichat

[permalink] [raw]
Subject: Re: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

On Wed, Oct 28, 2020 at 12:25 AM Enric Balletbo i Serra
<[email protected]> wrote:
>
> Hi Nicolas,
>
> On 27/10/20 1:19, Nicolas Boichat wrote:
> > Hi Enric,
> >
> > On Mon, Oct 26, 2020 at 11:17 PM Enric Balletbo i Serra
> > <[email protected]> wrote:
> >>
> >> Hi Nicolas,
> >>
> >> Many thanks for looking at this.
> >
> > Thanks to you ,-)
> >
> > [snip]
> >>>> + if (id >= scpsys->soc_data->num_domains) {
> >>>> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
> >>>> + return -EINVAL;
> >>>> + }
> >>>> +
> >>>> + domain_data = &scpsys->soc_data->domains[id];
> >>>> + if (!domain_data) {
> >>>
> >>> Is that even possible at all? I mean, even if
> >>> scpsys->soc_data->domains is NULL, as long as id != 0, this will no
> >>> happen.
> >>>
> >>
> >> I think could happen with a bad DT definition. I.e if for the definition of the
> >> MT8173 domains you use a wrong value for the reg property, a value that is not
> >> present in the SoC data. It is unlikely if you use the defines but could happen
> >> if you hardcore the value. We cannot check this with the DT json-schema.
> >
> > I wasn't clear in my explanation, and looking further there is more
> > that looks wrong.
> >
> > This expression &scpsys->soc_data->domains[id] is a pointer to element
> > "id" of the array domains. So if you convert to integer arithmetic,
> > it'll be something like `(long)scpsys->soc_data->domains +
> > (sizeof(struct generic_pm_domain *)) * id`. The only way this can be
> > NULL is if scpsys->soc_data->domains pointer is NULL, which, actually,
> > can't really happen as it's the 5th element of a struct scpsys
> > structure `(long)scpsys->soc_data + offset_of(domains, struct scpsys)
> > + (sizeof(struct generic_pm_domain *)) * id`.
> >
> > I think what you mean is either:
> > domain_data = &scpsys->soc_data->domains[id];
> > if (!*domain_data)
> > [but then domain_data type should be `struct generic_pm_domain **`?
>
> I think you're confusing the field `struct generic_pm_domain *domains[]`from the
> `struct scpsys` with `const struct scpsys_domain_data *domains` from `struct
> scpsys_soc_data`. My bad they have the same name, I should probably rename the
> second one as domain_info or domain_data to avoid that confusion.

Oh, okay, get it, thanks for clarifying, I got myself confused indeed ,-P

But, still, part of my integer arithmetics still holds...

&scpsys->soc_data->domains[id] = (long)scpsys->soc_data->domains +
(sizeof(struct generic_pm_domain *)) * id. The only way domain_data
can be NULL is if scpsys->soc_data->domains pointer is NULL (it can't
be, really, assuming scpsys_soc_data structures are well defined) AND
id is 0.

Now, if I understand what you want to check here. If a domain id is
not specified in scpsys_domain_data (e.g. if there is a gap in
MT8XXX_POWER_DOMAIN_YYY indices and if `id` points at one of those
gaps), you'll get an all-zero entry in domain_data. So maybe you can
just check that domain_data->sta_mask != 0? Would that be enough? (I
expect that sta_mask would always need to be set?)

But then again, are there ever gaps in MT8XXX_POWER_DOMAIN_YYY indices?

>
>
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.h
> b/drivers/soc/mediatek/mtk-pm-domains.h
> index 7c8efcb3cef2..6ff095db8a27 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.h
> +++ b/drivers/soc/mediatek/mtk-pm-domains.h
> @@ -56,7 +56,7 @@ struct scpsys_domain_data {
> };
>
> struct scpsys_soc_data {
> - const struct scpsys_domain_data *domains;
> + const struct scpsys_domain_data *domain_data;
> int num_domains;
> int pwr_sta_offs;
> int pwr_sta2nd_offs;
>
> ---
>
> struct scpsys {
> ...
> const struct scpsys_soc_data *soc_data;
> ...
> struct generic_pm_domain *domains[];
> }
>
>
> domain_data = &scpsys->soc_data->domain_data[id];
> if (!domain_data)
>
> Thanks,
> Enric
>
>
> > Does your code compile with warnings enabled?]
> > or:
> > domain_data = scpsys->soc_data->domains[id];
> > if (!domain_data)
> > [then the test makes sense]
> >
> > [snip]
> >

2020-10-30 10:34:01

by Enric Balletbo i Serra

[permalink] [raw]
Subject: Re: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

Hi Nicolas,

On 28/10/20 2:13, Nicolas Boichat wrote:
> On Wed, Oct 28, 2020 at 12:25 AM Enric Balletbo i Serra
> <[email protected]> wrote:
>>
>> Hi Nicolas,
>>
>> On 27/10/20 1:19, Nicolas Boichat wrote:
>>> Hi Enric,
>>>
>>> On Mon, Oct 26, 2020 at 11:17 PM Enric Balletbo i Serra
>>> <[email protected]> wrote:
>>>>
>>>> Hi Nicolas,
>>>>
>>>> Many thanks for looking at this.
>>>
>>> Thanks to you ,-)
>>>
>>> [snip]
>>>>>> + if (id >= scpsys->soc_data->num_domains) {
>>>>>> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
>>>>>> + return -EINVAL;
>>>>>> + }
>>>>>> +
>>>>>> + domain_data = &scpsys->soc_data->domains[id];
>>>>>> + if (!domain_data) {
>>>>>
>>>>> Is that even possible at all? I mean, even if
>>>>> scpsys->soc_data->domains is NULL, as long as id != 0, this will no
>>>>> happen.
>>>>>
>>>>
>>>> I think could happen with a bad DT definition. I.e if for the definition of the
>>>> MT8173 domains you use a wrong value for the reg property, a value that is not
>>>> present in the SoC data. It is unlikely if you use the defines but could happen
>>>> if you hardcore the value. We cannot check this with the DT json-schema.
>>>
>>> I wasn't clear in my explanation, and looking further there is more
>>> that looks wrong.
>>>
>>> This expression &scpsys->soc_data->domains[id] is a pointer to element
>>> "id" of the array domains. So if you convert to integer arithmetic,
>>> it'll be something like `(long)scpsys->soc_data->domains +
>>> (sizeof(struct generic_pm_domain *)) * id`. The only way this can be
>>> NULL is if scpsys->soc_data->domains pointer is NULL, which, actually,
>>> can't really happen as it's the 5th element of a struct scpsys
>>> structure `(long)scpsys->soc_data + offset_of(domains, struct scpsys)
>>> + (sizeof(struct generic_pm_domain *)) * id`.
>>>
>>> I think what you mean is either:
>>> domain_data = &scpsys->soc_data->domains[id];
>>> if (!*domain_data)
>>> [but then domain_data type should be `struct generic_pm_domain **`?
>>
>> I think you're confusing the field `struct generic_pm_domain *domains[]`from the
>> `struct scpsys` with `const struct scpsys_domain_data *domains` from `struct
>> scpsys_soc_data`. My bad they have the same name, I should probably rename the
>> second one as domain_info or domain_data to avoid that confusion.
>
> Oh, okay, get it, thanks for clarifying, I got myself confused indeed ,-P
>
> But, still, part of my integer arithmetics still holds...
>
> &scpsys->soc_data->domains[id] = (long)scpsys->soc_data->domains +
> (sizeof(struct generic_pm_domain *)) * id. The only way domain_data
> can be NULL is if scpsys->soc_data->domains pointer is NULL (it can't
> be, really, assuming scpsys_soc_data structures are well defined) AND
> id is 0.
>
> Now, if I understand what you want to check here. If a domain id is
> not specified in scpsys_domain_data (e.g. if there is a gap in
> MT8XXX_POWER_DOMAIN_YYY indices and if `id` points at one of those
> gaps), you'll get an all-zero entry in domain_data. So maybe you can
> just check that domain_data->sta_mask != 0? Would that be enough? (I
> expect that sta_mask would always need to be set?)
>

Yes, that would be enough. I'll change for the next version.

> But then again, are there ever gaps in MT8XXX_POWER_DOMAIN_YYY indices?
>

AFAIK, there is no gaps, but one could make gaps when filling that info. I
still think is worth have this check although is "unlikely" to happen due an
human error :-). I'll maintain for the next version, but I don't really care to
remove it if all you prefer I remove it.

Thanks,
Enric


>>
>>
>> diff --git a/drivers/soc/mediatek/mtk-pm-domains.h
>> b/drivers/soc/mediatek/mtk-pm-domains.h
>> index 7c8efcb3cef2..6ff095db8a27 100644
>> --- a/drivers/soc/mediatek/mtk-pm-domains.h
>> +++ b/drivers/soc/mediatek/mtk-pm-domains.h
>> @@ -56,7 +56,7 @@ struct scpsys_domain_data {
>> };
>>
>> struct scpsys_soc_data {
>> - const struct scpsys_domain_data *domains;
>> + const struct scpsys_domain_data *domain_data;
>> int num_domains;
>> int pwr_sta_offs;
>> int pwr_sta2nd_offs;
>>
>> ---
>>
>> struct scpsys {
>> ...
>> const struct scpsys_soc_data *soc_data;
>> ...
>> struct generic_pm_domain *domains[];
>> }
>>
>>
>> domain_data = &scpsys->soc_data->domain_data[id];
>> if (!domain_data)
>>
>> Thanks,
>> Enric
>>
>>
>>> Does your code compile with warnings enabled?]
>>> or:
>>> domain_data = scpsys->soc_data->domains[id];
>>> if (!domain_data)
>>> [then the test makes sense]
>>>
>>> [snip]
>>>

2020-10-30 12:48:04

by Nicolas Boichat

[permalink] [raw]
Subject: Re: [PATCH v2 02/12] soc: mediatek: Add MediaTek SCPSYS power domains

On Fri, Oct 30, 2020 at 6:30 PM Enric Balletbo i Serra
<[email protected]> wrote:
>
> Hi Nicolas,
>
> On 28/10/20 2:13, Nicolas Boichat wrote:
> > On Wed, Oct 28, 2020 at 12:25 AM Enric Balletbo i Serra
> > <[email protected]> wrote:
> >>
> >> Hi Nicolas,
> >>
> >> On 27/10/20 1:19, Nicolas Boichat wrote:
> >>> Hi Enric,
> >>>
> >>> On Mon, Oct 26, 2020 at 11:17 PM Enric Balletbo i Serra
> >>> <[email protected]> wrote:
> >>>>
> >>>> Hi Nicolas,
> >>>>
> >>>> Many thanks for looking at this.
> >>>
> >>> Thanks to you ,-)
> >>>
> >>> [snip]
> >>>>>> + if (id >= scpsys->soc_data->num_domains) {
> >>>>>> + dev_err_probe(scpsys->dev, -EINVAL, "%pOFn: invalid domain id %d\n", node, id);
> >>>>>> + return -EINVAL;
> >>>>>> + }
> >>>>>> +
> >>>>>> + domain_data = &scpsys->soc_data->domains[id];
> >>>>>> + if (!domain_data) {
> >>>>>
> >>>>> Is that even possible at all? I mean, even if
> >>>>> scpsys->soc_data->domains is NULL, as long as id != 0, this will no
> >>>>> happen.
> >>>>>
> >>>>
> >>>> I think could happen with a bad DT definition. I.e if for the definition of the
> >>>> MT8173 domains you use a wrong value for the reg property, a value that is not
> >>>> present in the SoC data. It is unlikely if you use the defines but could happen
> >>>> if you hardcore the value. We cannot check this with the DT json-schema.
> >>>
> >>> I wasn't clear in my explanation, and looking further there is more
> >>> that looks wrong.
> >>>
> >>> This expression &scpsys->soc_data->domains[id] is a pointer to element
> >>> "id" of the array domains. So if you convert to integer arithmetic,
> >>> it'll be something like `(long)scpsys->soc_data->domains +
> >>> (sizeof(struct generic_pm_domain *)) * id`. The only way this can be
> >>> NULL is if scpsys->soc_data->domains pointer is NULL, which, actually,
> >>> can't really happen as it's the 5th element of a struct scpsys
> >>> structure `(long)scpsys->soc_data + offset_of(domains, struct scpsys)
> >>> + (sizeof(struct generic_pm_domain *)) * id`.
> >>>
> >>> I think what you mean is either:
> >>> domain_data = &scpsys->soc_data->domains[id];
> >>> if (!*domain_data)
> >>> [but then domain_data type should be `struct generic_pm_domain **`?
> >>
> >> I think you're confusing the field `struct generic_pm_domain *domains[]`from the
> >> `struct scpsys` with `const struct scpsys_domain_data *domains` from `struct
> >> scpsys_soc_data`. My bad they have the same name, I should probably rename the
> >> second one as domain_info or domain_data to avoid that confusion.
> >
> > Oh, okay, get it, thanks for clarifying, I got myself confused indeed ,-P
> >
> > But, still, part of my integer arithmetics still holds...
> >
> > &scpsys->soc_data->domains[id] = (long)scpsys->soc_data->domains +
> > (sizeof(struct generic_pm_domain *)) * id. The only way domain_data
> > can be NULL is if scpsys->soc_data->domains pointer is NULL (it can't
> > be, really, assuming scpsys_soc_data structures are well defined) AND
> > id is 0.
> >
> > Now, if I understand what you want to check here. If a domain id is
> > not specified in scpsys_domain_data (e.g. if there is a gap in
> > MT8XXX_POWER_DOMAIN_YYY indices and if `id` points at one of those
> > gaps), you'll get an all-zero entry in domain_data. So maybe you can
> > just check that domain_data->sta_mask != 0? Would that be enough? (I
> > expect that sta_mask would always need to be set?)
> >
>
> Yes, that would be enough. I'll change for the next version.
>
> > But then again, are there ever gaps in MT8XXX_POWER_DOMAIN_YYY indices?
> >
>
> AFAIK, there is no gaps, but one could make gaps when filling that info. I
> still think is worth have this check although is "unlikely" to happen due an
> human error :-). I'll maintain for the next version, but I don't really care to
> remove it if all you prefer I remove it.

I'm fine with the sta_mask check. Thanks!

>
> Thanks,
> Enric
>
>
> >>
> >>
> >> diff --git a/drivers/soc/mediatek/mtk-pm-domains.h
> >> b/drivers/soc/mediatek/mtk-pm-domains.h
> >> index 7c8efcb3cef2..6ff095db8a27 100644
> >> --- a/drivers/soc/mediatek/mtk-pm-domains.h
> >> +++ b/drivers/soc/mediatek/mtk-pm-domains.h
> >> @@ -56,7 +56,7 @@ struct scpsys_domain_data {
> >> };
> >>
> >> struct scpsys_soc_data {
> >> - const struct scpsys_domain_data *domains;
> >> + const struct scpsys_domain_data *domain_data;
> >> int num_domains;
> >> int pwr_sta_offs;
> >> int pwr_sta2nd_offs;
> >>
> >> ---
> >>
> >> struct scpsys {
> >> ...
> >> const struct scpsys_soc_data *soc_data;
> >> ...
> >> struct generic_pm_domain *domains[];
> >> }
> >>
> >>
> >> domain_data = &scpsys->soc_data->domain_data[id];
> >> if (!domain_data)
> >>
> >> Thanks,
> >> Enric
> >>
> >>
> >>> Does your code compile with warnings enabled?]
> >>> or:
> >>> domain_data = scpsys->soc_data->domains[id];
> >>> if (!domain_data)
> >>> [then the test makes sense]
> >>>
> >>> [snip]
> >>>