Re: [PATCH v3] thermal: k3_j72xx_bandgap: implement suspend/resume support

From: Daniel Lezcano
Date: Mon Apr 22 2024 - 11:46:15 EST


On 17/04/2024 14:03, Thomas Richard wrote:
From: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>

This add suspend-to-ram support.

The derived_table is kept-as is, so the resume is only about
pm_runtime_* calls and restoring the same registers as the probe.

Extract the hardware initialization procedure to a function called at
both probe-time & resume-time.

The probe-time loop is split in two to ensure doing the hardware
initialization before registering thermal zones. That ensures our
callbacks cannot be called while in bad state.

Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
Acked-by: Keerthy <j-keerthy@xxxxxx>
Signed-off-by: Thomas Richard <thomas.richard@xxxxxxxxxxx>
---

v3:
- Remove __maybe_unused attributes and use the magic of PTR_IF()

Where are these changes ?

v2:
- Fix warnings/errors reported by kernel test robot

drivers/thermal/k3_j72xx_bandgap.c | 112 ++++++++++++++++++++---------
1 file changed, 79 insertions(+), 33 deletions(-)

diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
index c74094a86982..a7244e05ed5c 100644
--- a/drivers/thermal/k3_j72xx_bandgap.c
+++ b/drivers/thermal/k3_j72xx_bandgap.c
@@ -178,6 +178,7 @@ struct k3_j72xx_bandgap {
void __iomem *base;
void __iomem *cfg2_base;
struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
+ int cnt;
};
/* common data structures */
@@ -338,24 +339,53 @@ static void print_look_up_table(struct device *dev, int *ref_table)
dev_dbg(dev, "%d %d %d\n", i, derived_table[i], ref_table[i]);
}
+static void k3_j72xx_bandgap_init_hw(struct k3_j72xx_bandgap *bgp)
+{
+ struct k3_thermal_data *data;
+ int id, high_max, low_temp;
+ u32 val;
+
+ for (id = 0; id < bgp->cnt; id++) {
+ data = bgp->ts_data[id];
+ val = readl(bgp->cfg2_base + data->ctrl_offset);
+ val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
+ K3_VTM_TMPSENS_CTRL_SOC |
+ K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
+ writel(val, bgp->cfg2_base + data->ctrl_offset);
+ }
+
+ /*
+ * Program TSHUT thresholds
+ * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
+ * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN bit
+ * This is already taken care as per of init
+ * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN bit
+ */
+ high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
+ low_temp = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
+
+ writel((low_temp << 16) | high_max, bgp->cfg2_base + K3_VTM_MISC_CTRL2_OFFSET);
+ mdelay(100);

100ms ?

Ok, I know you did not introduce this delay. But as it is a suspend / resume, this delay will be called at each resume which is not acceptable given its duration.

Please, investigate a way to get rid of this delay


+ writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, bgp->cfg2_base + K3_VTM_MISC_CTRL_OFFSET);
+}
+
struct k3_j72xx_bandgap_data {
const bool has_errata_i2128;
};
static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
{
- int ret = 0, cnt, val, id;
- int high_max, low_temp;
- struct resource *res;
+ const struct k3_j72xx_bandgap_data *driver_data;
+ struct thermal_zone_device *ti_thermal;
struct device *dev = &pdev->dev;
+ bool workaround_needed = false;
struct k3_j72xx_bandgap *bgp;
struct k3_thermal_data *data;
- bool workaround_needed = false;
- const struct k3_j72xx_bandgap_data *driver_data;
- struct thermal_zone_device *ti_thermal;
- int *ref_table;
struct err_values err_vals;
void __iomem *fuse_base;
+ int ret = 0, val, id;
+ struct resource *res;
+ int *ref_table;

No related to the changes but the patch is showing signs the driver needs a code cleanup AFAICT

const s64 golden_factors[] = {
-490019999999999936,
@@ -422,10 +452,10 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
/* Get the sensor count in the VTM */
val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
- cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
- cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
+ bgp->cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
+ bgp->cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
- data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
+ data = devm_kcalloc(bgp->dev, bgp->cnt, sizeof(*data), GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
goto err_alloc;
@@ -449,8 +479,8 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
else
init_table(3, ref_table, pvt_wa_factors);
- /* Register the thermal sensors */
- for (id = 0; id < cnt; id++) {
+ /* Precompute the derived table & fill each thermal sensor struct */
+ for (id = 0; id < bgp->cnt; id++) {
data[id].bgp = bgp;
data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
data[id].stat_offset = data[id].ctrl_offset +
@@ -470,13 +500,13 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
else if (id == 0 && !workaround_needed)
memcpy(derived_table, ref_table, TABLE_SIZE * 4);
- val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset);
- val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
- K3_VTM_TMPSENS_CTRL_SOC |
- K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
- writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
-
bgp->ts_data[id] = &data[id];
+ }
+
+ k3_j72xx_bandgap_init_hw(bgp);
+
+ /* Register the thermal sensors */
+ for (id = 0; id < bgp->cnt; id++) {
ti_thermal = devm_thermal_of_zone_register(bgp->dev, id, &data[id],
&k3_of_thermal_ops);
if (IS_ERR(ti_thermal)) {
@@ -486,21 +516,7 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
}
}
- /*
- * Program TSHUT thresholds
- * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
- * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN bit
- * This is already taken care as per of init
- * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN bit
- */
- high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
- low_temp = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
-
- writel((low_temp << 16) | high_max, data[0].bgp->cfg2_base +
- K3_VTM_MISC_CTRL2_OFFSET);
- mdelay(100);
- writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
- K3_VTM_MISC_CTRL_OFFSET);
+ platform_set_drvdata(pdev, bgp);
print_look_up_table(dev, ref_table);
/*
@@ -527,6 +543,35 @@ static void k3_j72xx_bandgap_remove(struct platform_device *pdev)
pm_runtime_disable(&pdev->dev);
}
+static int k3_j72xx_bandgap_suspend(struct device *dev)
+{
+ pm_runtime_put_sync(dev);
+ pm_runtime_disable(dev);
+ return 0;
+}
+
+static int k3_j72xx_bandgap_resume(struct device *dev)
+{
+ struct k3_j72xx_bandgap *bgp = dev_get_drvdata(dev);
+ int ret;
+
+ pm_runtime_enable(dev);
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(dev);
+ pm_runtime_disable(dev);
+ return ret;
+ }
+
+ k3_j72xx_bandgap_init_hw(bgp);
+
+ return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(k3_j72xx_bandgap_pm_ops,
+ k3_j72xx_bandgap_suspend,
+ k3_j72xx_bandgap_resume);
+
static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = {
.has_errata_i2128 = true,
};
@@ -554,6 +599,7 @@ static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
.driver = {
.name = "k3-j72xx-soc-thermal",
.of_match_table = of_k3_j72xx_bandgap_match,
+ .pm = pm_sleep_ptr(&k3_j72xx_bandgap_pm_ops),
},
};

--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog