[PATCH v2 0/3] STM32MP15 OTG params updates

[PATCH v2 0/3] STM32MP15 OTG params updates

[Amelie Delaunay]

This patchset brings some updates on STM32MP15 OTG HS and FS.
It sets ahbcfg parameter for both HS and FS as the value reported by the
hardware is not recommended.
It also disables Link Power Management on OTG HS because with some Host
controllers (at least seen with some USB 3.2 Gen2 controllers), OTG doesn't
succeed to exit L1 state.
It also enables FS/LS PHY clock selection when the Core is in FS Host mode,
to have 6MHz PHY clock when the connected device is LS, and 48Mhz PHY clock
otherwise. 

---
Changes in v2:
- Move author mail address from @st.com to @foss.st.com
- Add Minas' Reviewed-by on all patches

Amelie Delaunay (3):
  usb: dwc2: set ahbcfg parameter for STM32MP15 OTG HS and FS
  usb: dwc2: enable FS/LS PHY clock select on STM32MP15 FS OTG
  usb: dwc2: disable Link Power Management on STM32MP15 HS OTG

 drivers/usb/dwc2/params.c | 8 ++++++++
 1 file changed, 8 insertions(+)

-- 
2.17.1

[PATCH v2 1/3] usb: dwc2: set ahbcfg parameter for STM32MP15 OTG HS and FS

[Amelie Delaunay]

STM32MP15 ahbcfg register default value sets Burst length/type (HBSTLEN)
to Single (32-bit accesses on AHB), which is not recommended, according
to STM32MP157 Reference manual [1].
This patch sets Burst length/type (HBSTLEN) so that bus transactions
target 16x32 bit accesses. This improves OTG controller performance.

[1] https://www.st.com/resource/en/reference_manual/dm00327659.pdf, p.3149

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
---
 drivers/usb/dwc2/params.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
index 267543c3dc38..0df693319f0a 100644
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -177,6 +177,7 @@ static void dwc2_set_stm32mp15_fsotg_params(struct dwc2_hsotg *hsotg)
 	p->i2c_enable = false;
 	p->activate_stm_fs_transceiver = true;
 	p->activate_stm_id_vb_detection = true;
+	p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 << GAHBCFG_HBSTLEN_SHIFT;
 	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;
 }
 
@@ -189,6 +190,7 @@ static void dwc2_set_stm32mp15_hsotg_params(struct dwc2_hsotg *hsotg)
 	p->host_rx_fifo_size = 440;
 	p->host_nperio_tx_fifo_size = 256;
 	p->host_perio_tx_fifo_size = 256;
+	p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 << GAHBCFG_HBSTLEN_SHIFT;
 	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;
 }
 
-- 
2.17.1

[PATCH v2 2/3] usb: dwc2: enable FS/LS PHY clock select on STM32MP15 FS OTG

[Amelie Delaunay]

When the core is in FS host mode, using the FS transceiver, and a Low-Speed
device is connected, transceiver clock is 6Mhz.
So, to support Low-Speed devices, enable support of FS/LS Low Power mode,
so that the PHY supplies a 6 MHz clock during Low-Speed mode.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
---
 drivers/usb/dwc2/params.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
index 0df693319f0a..9e5dd7f3f2f6 100644
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -179,6 +179,8 @@ static void dwc2_set_stm32mp15_fsotg_params(struct dwc2_hsotg *hsotg)
 	p->activate_stm_id_vb_detection = true;
 	p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 << GAHBCFG_HBSTLEN_SHIFT;
 	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;
+	p->host_support_fs_ls_low_power = true;
+	p->host_ls_low_power_phy_clk = true;
 }
 
 static void dwc2_set_stm32mp15_hsotg_params(struct dwc2_hsotg *hsotg)
-- 
2.17.1

[PATCH v2 3/3] usb: dwc2: disable Link Power Management on STM32MP15 HS OTG

[Amelie Delaunay]

Link Power Management (LPM) on STM32MP15 OTG HS encounters instabilities
with some Host controllers. OTG core fails to exit L1 state in 200us:
"dwc2 49000000.usb-otg: Failed to exit L1 sleep state in 200us."
Then the device is still not enumerated.

To avoid this issue, disable Link Power Management on STM32MP15 HS OTG.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
---
 drivers/usb/dwc2/params.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
index 9e5dd7f3f2f6..92df3d620f7d 100644
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -194,6 +194,10 @@ static void dwc2_set_stm32mp15_hsotg_params(struct dwc2_hsotg *hsotg)
 	p->host_perio_tx_fifo_size = 256;
 	p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 << GAHBCFG_HBSTLEN_SHIFT;
 	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;
+	p->lpm = false;
+	p->lpm_clock_gating = false;
+	p->besl = false;
+	p->hird_threshold_en = false;
 }
 
 const struct of_device_id dwc2_of_match_table[] = {
-- 
2.17.1