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From:   Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To:     rafael@kernel.org, rui.zhang@intel.com, daniel.lezcano@linaro.org
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Subject: [PATCH v2] thermal/drivers/intel/int340x: Add DLVR support
Date:   Thu, 13 Apr 2023 14:37:53 -0700
Message-Id: <20230413213753.129962-1-srinivas.pandruvada@linux.intel.com>
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Precedence: bulk

Add support for DLVR (Digital Linear Voltage Regulator) attributes,
which can be used to control RFIM.
Here instead of "fivr" another directory "dlvr" is created with DLVR
attributes:

/sys/bus/pci/devices/0000:00:04.0/dlvr
├── dlvr_freq_mhz
├── dlvr_freq_select
├── dlvr_hardware_rev
├── dlvr_pll_busy
├── dlvr_rfim_enable
└── dlvr_spread_spectrum_pct
└── dlvr_control_mode
└── dlvr_control_lock

Attributes
dlvr_freq_mhz (RO):
Current DLVR PLL frequency in MHz.

dlvr_freq_select (RW):
Sets DLVR PLL clock frequency.

dlvr_hardware_rev (RO):
DLVR hardware revision.

dlvr_pll_busy (RO):
PLL can't accept frequency change when set.

dlvr_rfim_enable (RW):
0: Disable RF frequency hopping, 1: Enable RF frequency hopping.

dlvr_control_mode (RW):
Specifies how frequencies are spread. 0: Down spread, 1: Spread in Center.

dlvr_control_lock (RW):
1: future writes are ignored.

dlvr_spread_spectrum_pct (RW)
A write to this register updates the DLVR spread spectrum percent value.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
v2
- Updated documentation
- Added dlvr_control_lock attribute

 .../driver-api/thermal/intel_dptf.rst         | 46 +++++++++-
 .../processor_thermal_device.c                |  3 +-
 .../processor_thermal_device.h                |  1 +
 .../processor_thermal_device_pci.c            |  2 +-
 .../int340x_thermal/processor_thermal_rfim.c  | 92 ++++++++++++++++++-
 5 files changed, 135 insertions(+), 9 deletions(-)

diff --git a/Documentation/driver-api/thermal/intel_dptf.rst b/Documentation/driver-api/thermal/intel_dptf.rst
index f5c193cccbda..9ab4316322a1 100644
--- a/Documentation/driver-api/thermal/intel_dptf.rst
+++ b/Documentation/driver-api/thermal/intel_dptf.rst
@@ -184,8 +184,9 @@ ABI.
 DPTF Processor thermal RFIM interface
 --------------------------------------------
 
-RFIM interface allows adjustment of FIVR (Fully Integrated Voltage Regulator)
-and DDR (Double Data Rate)frequencies to avoid RF interference with WiFi and 5G.
+RFIM interface allows adjustment of FIVR (Fully Integrated Voltage Regulator),
+DDR (Double Data Rate) and DLVR (Digital Linear Voltage Regulator)
+frequencies to avoid RF interference with WiFi and 5G.
 
 Switching voltage regulators (VR) generate radiated EMI or RFI at the
 fundamental frequency and its harmonics. Some harmonics may interfere
@@ -196,6 +197,15 @@ small % and shift away the switching noise harmonic interference from
 radio channels.  OEM or ODMs can use the driver to control SOC IVR
 operation within the range where it does not impact IVR performance.
 
+Some products use DLVR instead of FIVR as switching voltage regulator.
+In this case attributes of DLVR must be adjusted instead of FIVR.
+
+While shifting the frequencies additional clock noise can be introduced,
+which is compensated by adjusting Spread spectrum percent. This helps
+to reduce the clock noise to meet regulatory compliance. This spreading
+% increases bandwidth of signal transmission and hence reduces the
+effects of interference, noise and signal fading.
+
 DRAM devices of DDR IO interface and their power plane can generate EMI
 at the data rates. Similar to IVR control mechanism, Intel offers a
 mechanism by which DDR data rates can be changed if several conditions
@@ -264,6 +274,38 @@ DVFS attributes
 ``rfi_disable (RW)``
 	Disable DDR rate change feature
 
+DLVR attributes
+
+:file:`/sys/bus/pci/devices/0000\:00\:04.0/dlvr/`
+
+``dlvr_hardware_rev`` (RO)
+	DLVR hardware revision.
+
+``dlvr_freq_mhz`` (RO)
+	Current DLVR PLL frequency in MHz.
+
+``dlvr_freq_select`` (RW)
+	Sets DLVR PLL clock frequency. Once set, and enabled via
+	dlvr_rfim_enable, the dlvr_freq_mhz will show the current
+	DLVR PLL frequency.
+
+``dlvr_pll_busy`` (RO)
+	PLL can't accept frequency change when set.
+
+``dlvr_rfim_enable`` (RW)
+	0: Disable RF frequency hopping, 1: Enable RF frequency hopping.
+
+``dlvr_spread_spectrum_pct`` (RW)
+	Sets DLVR spread spectrum percent value.
+
+``dlvr_control_mode`` (RW)
+        Specifies how frequencies are spread using spread spectrum.
+        0: Down spread,
+        1: Spread in the Center.
+
+``dlvr_control_lock`` (RW)
+    1: future writes are ignored.
+
 DPTF Power supply and Battery Interface
 ----------------------------------------
 
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c
index a1dc18be7609..3ca0a2f5937f 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c
@@ -337,7 +337,8 @@ int proc_thermal_mmio_add(struct pci_dev *pdev,
 	}
 
 	if (feature_mask & PROC_THERMAL_FEATURE_FIVR ||
-	    feature_mask & PROC_THERMAL_FEATURE_DVFS) {
+	    feature_mask & PROC_THERMAL_FEATURE_DVFS ||
+	    feature_mask & PROC_THERMAL_FEATURE_DLVR) {
 		ret = proc_thermal_rfim_add(pdev, proc_priv);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to add RFIM interface\n");
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h
index 7d52fcff4937..7acaa8f1b896 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h
@@ -60,6 +60,7 @@ struct rapl_mmio_regs {
 #define PROC_THERMAL_FEATURE_FIVR	0x02
 #define PROC_THERMAL_FEATURE_DVFS	0x04
 #define PROC_THERMAL_FEATURE_MBOX	0x08
+#define PROC_THERMAL_FEATURE_DLVR	0x10
 
 #if IS_ENABLED(CONFIG_PROC_THERMAL_MMIO_RAPL)
 int proc_thermal_rapl_add(struct pci_dev *pdev, struct proc_thermal_device *proc_priv);
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
index d71ee50e7878..8b260dd9221b 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pci.c
@@ -351,7 +351,7 @@ static SIMPLE_DEV_PM_OPS(proc_thermal_pci_pm, proc_thermal_pci_suspend,
 
 static const struct pci_device_id proc_thermal_pci_ids[] = {
 	{ PCI_DEVICE_DATA(INTEL, ADL_THERMAL, PROC_THERMAL_FEATURE_RAPL | PROC_THERMAL_FEATURE_FIVR | PROC_THERMAL_FEATURE_DVFS | PROC_THERMAL_FEATURE_MBOX) },
-	{ PCI_DEVICE_DATA(INTEL, MTLP_THERMAL, PROC_THERMAL_FEATURE_RAPL | PROC_THERMAL_FEATURE_FIVR | PROC_THERMAL_FEATURE_DVFS | PROC_THERMAL_FEATURE_MBOX) },
+	{ PCI_DEVICE_DATA(INTEL, MTLP_THERMAL, PROC_THERMAL_FEATURE_RAPL | PROC_THERMAL_FEATURE_FIVR | PROC_THERMAL_FEATURE_DVFS | PROC_THERMAL_FEATURE_MBOX | PROC_THERMAL_FEATURE_DLVR) },
 	{ PCI_DEVICE_DATA(INTEL, RPL_THERMAL, PROC_THERMAL_FEATURE_RAPL | PROC_THERMAL_FEATURE_FIVR | PROC_THERMAL_FEATURE_DVFS | PROC_THERMAL_FEATURE_MBOX) },
 	{ },
 };
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_rfim.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_rfim.c
index 92ed1213fe37..546b70434004 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_rfim.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_rfim.c
@@ -39,6 +39,29 @@ static const struct mmio_reg tgl_fivr_mmio_regs[] = {
 	{ 1, 0x5A14, 2, 0x3, 1}, /* fivr_fffc_rev */
 };
 
+static const char * const dlvr_strings[] = {
+	"dlvr_spread_spectrum_pct",
+	"dlvr_control_mode",
+	"dlvr_control_lock",
+	"dlvr_rfim_enable",
+	"dlvr_freq_select",
+	"dlvr_hardware_rev",
+	"dlvr_freq_mhz",
+	"dlvr_pll_busy",
+	NULL
+};
+
+static const struct mmio_reg dlvr_mmio_regs[] = {
+	{ 0, 0x15A08, 5, 0x1F, 0}, /* dlvr_spread_spectrum_pct */
+	{ 0, 0x15A08, 1, 0x1, 5}, /* dlvr_control_mode */
+	{ 0, 0x15A08, 1, 0x1, 6}, /* dlvr_control_lock */
+	{ 0, 0x15A08, 1, 0x1, 7}, /* dlvr_rfim_enable */
+	{ 0, 0x15A08, 12, 0xFFF, 8}, /* dlvr_freq_select */
+	{ 1, 0x15A10, 2, 0x3, 30}, /* dlvr_hardware_rev */
+	{ 1, 0x15A10, 16, 0xFFFF, 0}, /* dlvr_freq_mhz */
+	{ 1, 0x15A10, 1, 0x1, 16}, /* dlvr_pll_busy */
+};
+
 /* These will represent sysfs attribute names */
 static const char * const dvfs_strings[] = {
 	"rfi_restriction_run_busy",
@@ -78,14 +101,16 @@ static ssize_t suffix##_show(struct device *dev,\
 	int ret;\
 \
 	proc_priv = pci_get_drvdata(pdev);\
-	if (table) {\
+	if (table == 1) {\
 		match_strs = (const char **)dvfs_strings;\
 		mmio_regs = adl_dvfs_mmio_regs;\
-	} else { \
+	} else if (table == 2) { \
+		match_strs = (const char **)dlvr_strings;\
+		mmio_regs = dlvr_mmio_regs;\
+	} else {\
 		match_strs = (const char **)fivr_strings;\
 		mmio_regs = tgl_fivr_mmio_regs;\
 	} \
-	\
 	ret = match_string(match_strs, -1, attr->attr.name);\
 	if (ret < 0)\
 		return ret;\
@@ -109,10 +134,13 @@ static ssize_t suffix##_store(struct device *dev,\
 	u32 mask;\
 \
 	proc_priv = pci_get_drvdata(pdev);\
-	if (table) {\
+	if (table == 1) {\
 		match_strs = (const char **)dvfs_strings;\
 		mmio_regs = adl_dvfs_mmio_regs;\
-	} else { \
+	} else if (table == 2) { \
+		match_strs = (const char **)dlvr_strings;\
+		mmio_regs = dlvr_mmio_regs;\
+	} else {\
 		match_strs = (const char **)fivr_strings;\
 		mmio_regs = tgl_fivr_mmio_regs;\
 	} \
@@ -147,6 +175,47 @@ RFIM_STORE(spread_spectrum_clk_enable, 0)
 RFIM_STORE(rfi_vco_ref_code, 0)
 RFIM_STORE(fivr_fffc_rev, 0)
 
+RFIM_SHOW(dlvr_spread_spectrum_pct, 2)
+RFIM_SHOW(dlvr_control_mode, 2)
+RFIM_SHOW(dlvr_control_lock, 2)
+RFIM_SHOW(dlvr_hardware_rev, 2)
+RFIM_SHOW(dlvr_freq_mhz, 2)
+RFIM_SHOW(dlvr_pll_busy, 2)
+RFIM_SHOW(dlvr_freq_select, 2)
+RFIM_SHOW(dlvr_rfim_enable, 2)
+
+RFIM_STORE(dlvr_spread_spectrum_pct, 2)
+RFIM_STORE(dlvr_rfim_enable, 2)
+RFIM_STORE(dlvr_freq_select, 2)
+RFIM_STORE(dlvr_control_mode, 2)
+RFIM_STORE(dlvr_control_lock, 2)
+
+static DEVICE_ATTR_RW(dlvr_spread_spectrum_pct);
+static DEVICE_ATTR_RW(dlvr_control_mode);
+static DEVICE_ATTR_RW(dlvr_control_lock);
+static DEVICE_ATTR_RW(dlvr_freq_select);
+static DEVICE_ATTR_RO(dlvr_hardware_rev);
+static DEVICE_ATTR_RO(dlvr_freq_mhz);
+static DEVICE_ATTR_RO(dlvr_pll_busy);
+static DEVICE_ATTR_RW(dlvr_rfim_enable);
+
+static struct attribute *dlvr_attrs[] = {
+	&dev_attr_dlvr_spread_spectrum_pct.attr,
+	&dev_attr_dlvr_control_mode.attr,
+	&dev_attr_dlvr_control_lock.attr,
+	&dev_attr_dlvr_freq_select.attr,
+	&dev_attr_dlvr_hardware_rev.attr,
+	&dev_attr_dlvr_freq_mhz.attr,
+	&dev_attr_dlvr_pll_busy.attr,
+	&dev_attr_dlvr_rfim_enable.attr,
+	NULL
+};
+
+static const struct attribute_group dlvr_attribute_group = {
+	.attrs = dlvr_attrs,
+	.name = "dlvr"
+};
+
 static DEVICE_ATTR_RW(vco_ref_code_lo);
 static DEVICE_ATTR_RW(vco_ref_code_hi);
 static DEVICE_ATTR_RW(spread_spectrum_pct);
@@ -277,12 +346,22 @@ int proc_thermal_rfim_add(struct pci_dev *pdev, struct proc_thermal_device *proc
 			return ret;
 	}
 
+	if (proc_priv->mmio_feature_mask & PROC_THERMAL_FEATURE_DLVR) {
+		ret = sysfs_create_group(&pdev->dev.kobj, &dlvr_attribute_group);
+		if (ret)
+			return ret;
+	}
+
 	if (proc_priv->mmio_feature_mask & PROC_THERMAL_FEATURE_DVFS) {
 		ret = sysfs_create_group(&pdev->dev.kobj, &dvfs_attribute_group);
 		if (ret && proc_priv->mmio_feature_mask & PROC_THERMAL_FEATURE_FIVR) {
 			sysfs_remove_group(&pdev->dev.kobj, &fivr_attribute_group);
 			return ret;
 		}
+		if (ret && proc_priv->mmio_feature_mask & PROC_THERMAL_FEATURE_DLVR) {
+			sysfs_remove_group(&pdev->dev.kobj, &dlvr_attribute_group);
+			return ret;
+		}
 	}
 
 	return 0;
@@ -296,6 +375,9 @@ void proc_thermal_rfim_remove(struct pci_dev *pdev)
 	if (proc_priv->mmio_feature_mask & PROC_THERMAL_FEATURE_FIVR)
 		sysfs_remove_group(&pdev->dev.kobj, &fivr_attribute_group);
 
+	if (proc_priv->mmio_feature_mask & PROC_THERMAL_FEATURE_DLVR)
+		sysfs_remove_group(&pdev->dev.kobj, &dlvr_attribute_group);
+
 	if (proc_priv->mmio_feature_mask & PROC_THERMAL_FEATURE_DVFS)
 		sysfs_remove_group(&pdev->dev.kobj, &dvfs_attribute_group);
 }
-- 
2.38.1