[PATCH v2 1/5] usb: dwc3: Cache ref_clk pointer in struct dwc3

[PATCH v2 1/5] usb: dwc3: Cache ref_clk pointer in struct dwc3

[Marek Vasut]

Cache ref_clk clock pointer in struct dwc3 . This is a preparatory
patch for subsequent backports from Linux kernel which configure
GFLADJ register content based on the ref_clk rate and therefore need
access to the ref_clk pointer.

It is possible to extract the clock pointer from existing clk_bulk
list of already claimed clock, no need to call clk_get*() again.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Angus Ainslie <angus@akkea.ca>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sean Anderson <sean.anderson@seco.com>
Cc: Stefano Babic <sbabic@denx.de>
---
V2: Add paragraph on clk_get into commit message
---
 drivers/usb/dwc3/core.h         | 3 +++
 drivers/usb/dwc3/dwc3-generic.c | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index d7cce3a861a..0d20fe285b0 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -668,6 +668,7 @@ struct dwc3_scratchpad_array {
  * @event_buffer_list: a list of event buffers
  * @gadget: device side representation of the peripheral controller
  * @gadget_driver: pointer to the gadget driver
+ * @ref_clk: reference clock
  * @regs: base address for our registers
  * @regs_size: address space size
  * @nr_scratch: number of scratch buffers
@@ -766,6 +767,8 @@ struct dwc3 {
 	struct usb_gadget	gadget;
 	struct usb_gadget_driver *gadget_driver;
 
+	struct clk		*ref_clk;
+
 	void __iomem		*regs;
 	size_t			regs_size;
 
diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
index 466b25a0c38..78966718d01 100644
--- a/drivers/usb/dwc3/dwc3-generic.c
+++ b/drivers/usb/dwc3/dwc3-generic.c
@@ -59,12 +59,21 @@ static int dwc3_generic_probe(struct udevice *dev,
 	struct dwc3_generic_plat *plat = dev_get_plat(dev);
 	struct dwc3 *dwc3 = &priv->dwc3;
 	struct dwc3_glue_data *glue = dev_get_plat(dev->parent);
+	int __maybe_unused index;
+	ofnode __maybe_unused node;
 
 	dwc3->dev = dev;
 	dwc3->maximum_speed = plat->maximum_speed;
 	dwc3->dr_mode = plat->dr_mode;
 #if CONFIG_IS_ENABLED(OF_CONTROL)
 	dwc3_of_parse(dwc3);
+
+	node = dev_ofnode(dev->parent);
+	index = ofnode_stringlist_search(node, "clock-names", "ref");
+	if (index < 0)
+		index = ofnode_stringlist_search(node, "clock-names", "ref_clk");
+	if (index >= 0)
+		dwc3->ref_clk = &glue->clks.clks[index];
 #endif
 
 	/*
-- 
2.35.1

[PATCH v2 2/5] usb: dwc3: reference clock period configuration

[Marek Vasut]

From: Balaji Prakash J <bjagadee@codeaurora.org>

Set reference clock period when it differs from dwc3 default hardware
set.

We could calculate clock period based on reference clock frequency. But
this information is not always available. This is the case of PCI bus
attached USB host. For that reason we use a custom property.

Tested (USB2 only) on IPQ6010 SoC based board with 24 MHz reference
clock while hardware default is 19.2 MHz.

[ baruch: rewrite commit message; drop GFLADJ code; remove 'quirk-' from
  property name; mention tested hardware ]

[ marek: Ported from Linux kernel commit
         7bee318838890 ("usb: dwc3: reference clock period configuration") ]

Signed-off-by: Balaji Prakash J <bjagadee@codeaurora.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Marek Vasut <marex@denx.de> # Port from Linux
---
Cc: Angus Ainslie <angus@akkea.ca>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sean Anderson <sean.anderson@seco.com>
Cc: Stefano Babic <sbabic@denx.de>
---
V2: No change
---
 drivers/usb/dwc3/core.c | 27 +++++++++++++++++++++++++++
 drivers/usb/dwc3/core.h |  6 ++++++
 2 files changed, 33 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index b592a487e00..300450100c9 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -28,6 +28,7 @@
 #include <generic-phy.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
+#include <linux/bitfield.h>
 
 #include "core.h"
 #include "gadget.h"
@@ -114,6 +115,28 @@ static void dwc3_frame_length_adjustment(struct dwc3 *dwc, u32 fladj)
 	dwc3_writel(dwc->regs, DWC3_GFLADJ, reg);
 }
 
+/**
+ * dwc3_ref_clk_period - Reference clock period configuration
+ *		Default reference clock period depends on hardware
+ *		configuration. For systems with reference clock that differs
+ *		from the default, this will set clock period in DWC3_GUCTL
+ *		register.
+ * @dwc: Pointer to our controller context structure
+ * @ref_clk_per: reference clock period in ns
+ */
+static void dwc3_ref_clk_period(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	if (dwc->ref_clk_per == 0)
+		return;
+
+	reg = dwc3_readl(dwc->regs, DWC3_GUCTL);
+	reg &= ~DWC3_GUCTL_REFCLKPER_MASK;
+	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, dwc->ref_clk_per);
+	dwc3_writel(dwc->regs, DWC3_GUCTL, reg);
+}
+
 /**
  * dwc3_free_one_event_buffer - Frees one event buffer
  * @dwc: Pointer to our controller context structure
@@ -640,6 +663,9 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	/* Adjust Frame Length */
 	dwc3_frame_length_adjustment(dwc, dwc->fladj);
 
+	/* Adjust Reference Clock Period */
+	dwc3_ref_clk_period(dwc);
+
 	dwc3_set_incr_burst_type(dwc);
 
 	return 0;
@@ -1043,6 +1069,7 @@ void dwc3_of_parse(struct dwc3 *dwc)
 		| (dwc->is_utmi_l1_suspend << 4);
 
 	dev_read_u32(dev, "snps,quirk-frame-length-adjustment", &dwc->fladj);
+	dev_read_u32(dev, "snps,ref-clock-period-ns", &dwc->ref_clk_per);
 
 	/*
 	 * Handle property "snps,incr-burst-type-adjustment".
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 0d20fe285b0..b4a7d9e52bc 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -249,6 +249,10 @@
 #define DWC3_GFLADJ_30MHZ_SDBND_SEL		(1 << 7)
 #define DWC3_GFLADJ_30MHZ_MASK			0x3f
 
+/* Global User Control Register*/
+#define DWC3_GUCTL_REFCLKPER_MASK		0xffc00000
+#define DWC3_GUCTL_REFCLKPER_SEL		22
+
 /* Device Configuration Register */
 #define DWC3_DCFG_DEVADDR(addr)	((addr) << 3)
 #define DWC3_DCFG_DEVADDR_MASK	DWC3_DCFG_DEVADDR(0x7f)
@@ -671,6 +675,7 @@ struct dwc3_scratchpad_array {
  * @ref_clk: reference clock
  * @regs: base address for our registers
  * @regs_size: address space size
+ * @ref_clk_per: reference clock period configuration
  * @nr_scratch: number of scratch buffers
  * @num_event_buffers: calculated number of event buffers
  * @u1u2: only used on revisions <1.83a for workaround
@@ -832,6 +837,7 @@ struct dwc3 {
 	u8			lpm_nyet_threshold;
 	u8			hird_threshold;
 	u32			fladj;
+	u32			ref_clk_per;
 	u8			incrx_mode;
 	u32			incrx_size;
 
-- 
2.35.1

[PATCH v2 3/5] usb: dwc3: Calculate REFCLKPER based on reference clock

[Marek Vasut]

From: Sean Anderson <sean.anderson@seco.com>

Instead of using a special property to determine the reference clock
period, use the rate of the reference clock. When we have a legacy
snps,ref-clock-period-ns property and no reference clock, use it
instead. Fractional clocks are not currently supported, and will be
dealt with in the next commit.

[ marek: Ported from Linux kernel commit
         5114c3ee24875 ("usb: dwc3: Calculate REFCLKPER based on reference clock") ]

Reviewed-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Marek Vasut <marex@denx.de> # Port from Linux
---
Cc: Angus Ainslie <angus@akkea.ca>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sean Anderson <sean.anderson@seco.com>
Cc: Stefano Babic <sbabic@denx.de>
---
V2: No change
---
 drivers/usb/dwc3/core.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 300450100c9..cf66976a088 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -126,14 +126,24 @@ static void dwc3_frame_length_adjustment(struct dwc3 *dwc, u32 fladj)
  */
 static void dwc3_ref_clk_period(struct dwc3 *dwc)
 {
+	unsigned long period;
+	unsigned long rate;
 	u32 reg;
 
-	if (dwc->ref_clk_per == 0)
+	if (dwc->ref_clk) {
+		rate = clk_get_rate(dwc->ref_clk);
+		if (!rate)
+			return;
+		period = NSEC_PER_SEC / rate;
+	} else if (dwc->ref_clk_per) {
+		period = dwc->ref_clk_per;
+	} else {
 		return;
+	}
 
 	reg = dwc3_readl(dwc->regs, DWC3_GUCTL);
 	reg &= ~DWC3_GUCTL_REFCLKPER_MASK;
-	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, dwc->ref_clk_per);
+	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, period);
 	dwc3_writel(dwc->regs, DWC3_GUCTL, reg);
 }
 
-- 
2.35.1

[PATCH v2 4/5] usb: dwc3: Program GFLADJ

[Marek Vasut]

From: Sean Anderson <sean.anderson@seco.com>

GUCTL.REFCLKPER can only account for clock frequencies with integer
periods. To address this, program REFCLK_FLADJ with the relative error
caused by period truncation. The formula given in the register reference
has been rearranged to allow calculation based on rate (instead of
period), and to allow for fixed-point arithmetic.

Additionally, calculate a value for 240MHZDECR. This configures a
simulated 240Mhz clock using a counter with one fractional bit (PLS1).

This register is programmed only for versions >= 2.50a, since this is
the check also used by commit db2be4e9e30c ("usb: dwc3: Add frame length
adjustment quirk").

[ marek: Ported from Linux kernel commit
         596c87856e08d ("usb: dwc3: Program GFLADJ") ]

Reviewed-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Marek Vasut <marex@denx.de> # Port from Linux
---
Cc: Angus Ainslie <angus@akkea.ca>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sean Anderson <sean.anderson@seco.com>
Cc: Stefano Babic <sbabic@denx.de>
---
V2: No change
---
 drivers/usb/dwc3/core.c | 41 +++++++++++++++++++++++++++++++++++++++++
 drivers/usb/dwc3/core.h |  3 +++
 2 files changed, 44 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index cf66976a088..fcd062dc898 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -29,6 +29,7 @@
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
 #include <linux/bitfield.h>
+#include <linux/math64.h>
 
 #include "core.h"
 #include "gadget.h"
@@ -36,6 +37,8 @@
 
 #include "linux-compat.h"
 
+#define NSEC_PER_SEC	1000000000L
+
 static LIST_HEAD(dwc3_list);
 /* -------------------------------------------------------------------------- */
 
@@ -127,6 +130,8 @@ static void dwc3_frame_length_adjustment(struct dwc3 *dwc, u32 fladj)
 static void dwc3_ref_clk_period(struct dwc3 *dwc)
 {
 	unsigned long period;
+	unsigned long fladj;
+	unsigned long decr;
 	unsigned long rate;
 	u32 reg;
 
@@ -137,6 +142,7 @@ static void dwc3_ref_clk_period(struct dwc3 *dwc)
 		period = NSEC_PER_SEC / rate;
 	} else if (dwc->ref_clk_per) {
 		period = dwc->ref_clk_per;
+		rate = NSEC_PER_SEC / period;
 	} else {
 		return;
 	}
@@ -145,6 +151,41 @@ static void dwc3_ref_clk_period(struct dwc3 *dwc)
 	reg &= ~DWC3_GUCTL_REFCLKPER_MASK;
 	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, period);
 	dwc3_writel(dwc->regs, DWC3_GUCTL, reg);
+
+	if (dwc->revision <= DWC3_REVISION_250A)
+		return;
+
+	/*
+	 * The calculation below is
+	 *
+	 * 125000 * (NSEC_PER_SEC / (rate * period) - 1)
+	 *
+	 * but rearranged for fixed-point arithmetic. The division must be
+	 * 64-bit because 125000 * NSEC_PER_SEC doesn't fit in 32 bits (and
+	 * neither does rate * period).
+	 *
+	 * Note that rate * period ~= NSEC_PER_SECOND, minus the number of
+	 * nanoseconds of error caused by the truncation which happened during
+	 * the division when calculating rate or period (whichever one was
+	 * derived from the other). We first calculate the relative error, then
+	 * scale it to units of 8 ppm.
+	 */
+	fladj = div64_u64(125000ULL * NSEC_PER_SEC, (u64)rate * period);
+	fladj -= 125000;
+
+	/*
+	 * The documented 240MHz constant is scaled by 2 to get PLS1 as well.
+	 */
+	decr = 480000000 / rate;
+
+	reg = dwc3_readl(dwc->regs, DWC3_GFLADJ);
+	reg &= ~DWC3_GFLADJ_REFCLK_FLADJ_MASK
+	    &  ~DWC3_GFLADJ_240MHZDECR
+	    &  ~DWC3_GFLADJ_240MHZDECR_PLS1;
+	reg |= FIELD_PREP(DWC3_GFLADJ_REFCLK_FLADJ_MASK, fladj)
+	    |  FIELD_PREP(DWC3_GFLADJ_240MHZDECR, decr >> 1)
+	    |  FIELD_PREP(DWC3_GFLADJ_240MHZDECR_PLS1, decr & 1);
+	dwc3_writel(dwc->regs, DWC3_GFLADJ, reg);
 }
 
 /**
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index b4a7d9e52bc..532746dd88d 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -248,6 +248,9 @@
 /* Global Frame Length Adjustment Register */
 #define DWC3_GFLADJ_30MHZ_SDBND_SEL		(1 << 7)
 #define DWC3_GFLADJ_30MHZ_MASK			0x3f
+#define DWC3_GFLADJ_REFCLK_FLADJ_MASK		GENMASK(21, 8)
+#define DWC3_GFLADJ_240MHZDECR			GENMASK(30, 24)
+#define DWC3_GFLADJ_240MHZDECR_PLS1		BIT(31)
 
 /* Global User Control Register*/
 #define DWC3_GUCTL_REFCLKPER_MASK		0xffc00000
-- 
2.35.1

[PATCH v2 5/5] usb: dwc3: Drop support for "snps, ref-clock-period-ns" DT property

[Marek Vasut]

Drop support for quickly deprecated DT property "snps,ref-clock-period-ns"
to prevent its proliferation.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Angus Ainslie <angus@akkea.ca>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sean Anderson <sean.anderson@seco.com>
Cc: Stefano Babic <sbabic@denx.de>
---
V2: New patch
---
 drivers/usb/dwc3/core.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index fcd062dc898..a0d3a9d5eea 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -140,9 +140,6 @@ static void dwc3_ref_clk_period(struct dwc3 *dwc)
 		if (!rate)
 			return;
 		period = NSEC_PER_SEC / rate;
-	} else if (dwc->ref_clk_per) {
-		period = dwc->ref_clk_per;
-		rate = NSEC_PER_SEC / period;
 	} else {
 		return;
 	}
@@ -1120,7 +1117,6 @@ void dwc3_of_parse(struct dwc3 *dwc)
 		| (dwc->is_utmi_l1_suspend << 4);
 
 	dev_read_u32(dev, "snps,quirk-frame-length-adjustment", &dwc->fladj);
-	dev_read_u32(dev, "snps,ref-clock-period-ns", &dwc->ref_clk_per);
 
 	/*
 	 * Handle property "snps,incr-burst-type-adjustment".
-- 
2.35.1

Re: [PATCH v2 1/5] usb: dwc3: Cache ref_clk pointer in struct dwc3

[Sean Anderson]

On 11/7/22 20:40, Marek Vasut wrote:
> Cache ref_clk clock pointer in struct dwc3 . This is a preparatory
> patch for subsequent backports from Linux kernel which configure
> GFLADJ register content based on the ref_clk rate and therefore need
> access to the ref_clk pointer.
> 
> It is possible to extract the clock pointer from existing clk_bulk
> list of already claimed clock, no need to call clk_get*() again.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> ---
> Cc: Angus Ainslie <angus@akkea.ca>
> Cc: Bin Meng <bmeng.cn@gmail.com>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Peng Fan <peng.fan@nxp.com>
> Cc: Sean Anderson <sean.anderson@seco.com>
> Cc: Stefano Babic <sbabic@denx.de>
> ---
> V2: Add paragraph on clk_get into commit message
> ---
>   drivers/usb/dwc3/core.h         | 3 +++
>   drivers/usb/dwc3/dwc3-generic.c | 9 +++++++++
>   2 files changed, 12 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index d7cce3a861a..0d20fe285b0 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -668,6 +668,7 @@ struct dwc3_scratchpad_array {
>    * @event_buffer_list: a list of event buffers
>    * @gadget: device side representation of the peripheral controller
>    * @gadget_driver: pointer to the gadget driver
> + * @ref_clk: reference clock
>    * @regs: base address for our registers
>    * @regs_size: address space size
>    * @nr_scratch: number of scratch buffers
> @@ -766,6 +767,8 @@ struct dwc3 {
>   	struct usb_gadget	gadget;
>   	struct usb_gadget_driver *gadget_driver;
>   
> +	struct clk		*ref_clk;
> +
>   	void __iomem		*regs;
>   	size_t			regs_size;
>   
> diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
> index 466b25a0c38..78966718d01 100644
> --- a/drivers/usb/dwc3/dwc3-generic.c
> +++ b/drivers/usb/dwc3/dwc3-generic.c
> @@ -59,12 +59,21 @@ static int dwc3_generic_probe(struct udevice *dev,
>   	struct dwc3_generic_plat *plat = dev_get_plat(dev);
>   	struct dwc3 *dwc3 = &priv->dwc3;
>   	struct dwc3_glue_data *glue = dev_get_plat(dev->parent);
> +	int __maybe_unused index;
> +	ofnode __maybe_unused node;
>   
>   	dwc3->dev = dev;
>   	dwc3->maximum_speed = plat->maximum_speed;
>   	dwc3->dr_mode = plat->dr_mode;
>   #if CONFIG_IS_ENABLED(OF_CONTROL)
>   	dwc3_of_parse(dwc3);
> +
> +	node = dev_ofnode(dev->parent);
> +	index = ofnode_stringlist_search(node, "clock-names", "ref");
> +	if (index < 0)
> +		index = ofnode_stringlist_search(node, "clock-names", "ref_clk");
> +	if (index >= 0)
> +		dwc3->ref_clk = &glue->clks.clks[index];
>   #endif
>   
>   	/*

Reviewed-by: Sean Anderson <seanga2@gmail.com>

Re: [PATCH v2 2/5] usb: dwc3: reference clock period configuration

[Sean Anderson]

On 11/7/22 20:40, Marek Vasut wrote:
> From: Balaji Prakash J <bjagadee@codeaurora.org>
> 
> Set reference clock period when it differs from dwc3 default hardware
> set.
> 
> We could calculate clock period based on reference clock frequency. But
> this information is not always available. This is the case of PCI bus
> attached USB host. For that reason we use a custom property.
> 
> Tested (USB2 only) on IPQ6010 SoC based board with 24 MHz reference
> clock while hardware default is 19.2 MHz.
> 
> [ baruch: rewrite commit message; drop GFLADJ code; remove 'quirk-' from
>    property name; mention tested hardware ]
> 
> [ marek: Ported from Linux kernel commit
>           7bee318838890 ("usb: dwc3: reference clock period configuration") ]
> 
> Signed-off-by: Balaji Prakash J <bjagadee@codeaurora.org>
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
> Signed-off-by: Marek Vasut <marex@denx.de> # Port from Linux
> ---
> Cc: Angus Ainslie <angus@akkea.ca>
> Cc: Bin Meng <bmeng.cn@gmail.com>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Peng Fan <peng.fan@nxp.com>
> Cc: Sean Anderson <sean.anderson@seco.com>
> Cc: Stefano Babic <sbabic@denx.de>
> ---
> V2: No change
> ---
>   drivers/usb/dwc3/core.c | 27 +++++++++++++++++++++++++++
>   drivers/usb/dwc3/core.h |  6 ++++++
>   2 files changed, 33 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index b592a487e00..300450100c9 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -28,6 +28,7 @@
>   #include <generic-phy.h>
>   #include <linux/usb/ch9.h>
>   #include <linux/usb/gadget.h>
> +#include <linux/bitfield.h>
>   
>   #include "core.h"
>   #include "gadget.h"
> @@ -114,6 +115,28 @@ static void dwc3_frame_length_adjustment(struct dwc3 *dwc, u32 fladj)
>   	dwc3_writel(dwc->regs, DWC3_GFLADJ, reg);
>   }
>   
> +/**
> + * dwc3_ref_clk_period - Reference clock period configuration
> + *		Default reference clock period depends on hardware
> + *		configuration. For systems with reference clock that differs
> + *		from the default, this will set clock period in DWC3_GUCTL
> + *		register.
> + * @dwc: Pointer to our controller context structure
> + * @ref_clk_per: reference clock period in ns
> + */
> +static void dwc3_ref_clk_period(struct dwc3 *dwc)
> +{
> +	u32 reg;
> +
> +	if (dwc->ref_clk_per == 0)
> +		return;
> +
> +	reg = dwc3_readl(dwc->regs, DWC3_GUCTL);
> +	reg &= ~DWC3_GUCTL_REFCLKPER_MASK;
> +	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, dwc->ref_clk_per);
> +	dwc3_writel(dwc->regs, DWC3_GUCTL, reg);
> +}
> +
>   /**
>    * dwc3_free_one_event_buffer - Frees one event buffer
>    * @dwc: Pointer to our controller context structure
> @@ -640,6 +663,9 @@ static int dwc3_core_init(struct dwc3 *dwc)
>   	/* Adjust Frame Length */
>   	dwc3_frame_length_adjustment(dwc, dwc->fladj);
>   
> +	/* Adjust Reference Clock Period */
> +	dwc3_ref_clk_period(dwc);
> +
>   	dwc3_set_incr_burst_type(dwc);
>   
>   	return 0;
> @@ -1043,6 +1069,7 @@ void dwc3_of_parse(struct dwc3 *dwc)
>   		| (dwc->is_utmi_l1_suspend << 4);
>   
>   	dev_read_u32(dev, "snps,quirk-frame-length-adjustment", &dwc->fladj);
> +	dev_read_u32(dev, "snps,ref-clock-period-ns", &dwc->ref_clk_per);
>   
>   	/*
>   	 * Handle property "snps,incr-burst-type-adjustment".
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 0d20fe285b0..b4a7d9e52bc 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -249,6 +249,10 @@
>   #define DWC3_GFLADJ_30MHZ_SDBND_SEL		(1 << 7)
>   #define DWC3_GFLADJ_30MHZ_MASK			0x3f
>   
> +/* Global User Control Register*/
> +#define DWC3_GUCTL_REFCLKPER_MASK		0xffc00000
> +#define DWC3_GUCTL_REFCLKPER_SEL		22
> +
>   /* Device Configuration Register */
>   #define DWC3_DCFG_DEVADDR(addr)	((addr) << 3)
>   #define DWC3_DCFG_DEVADDR_MASK	DWC3_DCFG_DEVADDR(0x7f)
> @@ -671,6 +675,7 @@ struct dwc3_scratchpad_array {
>    * @ref_clk: reference clock
>    * @regs: base address for our registers
>    * @regs_size: address space size
> + * @ref_clk_per: reference clock period configuration
>    * @nr_scratch: number of scratch buffers
>    * @num_event_buffers: calculated number of event buffers
>    * @u1u2: only used on revisions <1.83a for workaround
> @@ -832,6 +837,7 @@ struct dwc3 {
>   	u8			lpm_nyet_threshold;
>   	u8			hird_threshold;
>   	u32			fladj;
> +	u32			ref_clk_per;
>   	u8			incrx_mode;
>   	u32			incrx_size;
>   

Reviewed-by: Sean Anderson <seanga2@gmail.com>

Re: [PATCH v2 5/5] usb: dwc3: Drop support for "snps, ref-clock-period-ns" DT property

[Sean Anderson]

On 11/7/22 20:40, Marek Vasut wrote:
> Drop support for quickly deprecated DT property "snps,ref-clock-period-ns"
> to prevent its proliferation.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> ---
> Cc: Angus Ainslie <angus@akkea.ca>
> Cc: Bin Meng <bmeng.cn@gmail.com>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Peng Fan <peng.fan@nxp.com>
> Cc: Sean Anderson <sean.anderson@seco.com>
> Cc: Stefano Babic <sbabic@denx.de>
> ---
> V2: New patch
> ---
>   drivers/usb/dwc3/core.c | 4 ----
>   1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index fcd062dc898..a0d3a9d5eea 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -140,9 +140,6 @@ static void dwc3_ref_clk_period(struct dwc3 *dwc)
>   		if (!rate)
>   			return;
>   		period = NSEC_PER_SEC / rate;
> -	} else if (dwc->ref_clk_per) {
> -		period = dwc->ref_clk_per;
> -		rate = NSEC_PER_SEC / period;
>   	} else {
>   		return;
>   	}
> @@ -1120,7 +1117,6 @@ void dwc3_of_parse(struct dwc3 *dwc)
>   		| (dwc->is_utmi_l1_suspend << 4);
>   
>   	dev_read_u32(dev, "snps,quirk-frame-length-adjustment", &dwc->fladj);
> -	dev_read_u32(dev, "snps,ref-clock-period-ns", &dwc->ref_clk_per);
>   
>   	/*
>   	 * Handle property "snps,incr-burst-type-adjustment".

Reviewed-by: Sean Anderson <seanga2@gmail.com>