All of lore.kernel.org
 help / color / mirror / Atom feed
* FAILED: patch "[PATCH] phy: cadence: cdns-dphy: Fix PLL lock and O_CMN_READY polling" failed to apply to 6.1-stable tree
@ 2025-10-16 13:06 gregkh
  2025-10-20 12:59 ` [PATCH 6.1.y 1/2] phy: cdns-dphy: Store hs_clk_rate and return it Sasha Levin
  0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2025-10-16 13:06 UTC (permalink / raw)
  To: devarsht, h-shenoy, tomi.valkeinen, vkoul; +Cc: stable


The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 284fb19a3ffb1083c3ad9c00d29749d09dddb99c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025101614-sphere-flagman-052d@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 284fb19a3ffb1083c3ad9c00d29749d09dddb99c Mon Sep 17 00:00:00 2001
From: Devarsh Thakkar <devarsht@ti.com>
Date: Fri, 4 Jul 2025 18:29:14 +0530
Subject: [PATCH] phy: cadence: cdns-dphy: Fix PLL lock and O_CMN_READY polling

PLL lockup and O_CMN_READY assertion can only happen after common state
machine gets enabled by programming DPHY_CMN_SSM register, but driver was
polling them before the common state machine was enabled which is
incorrect.  This is as per the DPHY initialization sequence as mentioned in
J721E TRM [1] at section "12.7.2.4.1.2.1 Start-up Sequence Timing Diagram".
It shows O_CMN_READY polling at the end after common configuration pin
setup where the common configuration pin setup step enables state machine
as referenced in "Table 12-1533. Common Configuration-Related Setup
mentions state machine"

To fix this :
- Add new function callbacks for polling on PLL lock and O_CMN_READY
  assertion.
- As state machine and clocks get enabled in power_on callback only, move
  the clock related programming part from configure callback to power_on
callback and poll for the PLL lockup and O_CMN_READY assertion after state
machine gets enabled.
- The configure callback only saves the PLL configuration received from the
  client driver which will be applied later on in power_on callback.
- Add checks to ensure configure is called before power_on and state
  machine is in disabled state before power_on callback is called.
- Disable state machine in power_off so that client driver can re-configure
  the PLL by following up a power_off, configure, power_on sequence.

[1]: https://www.ti.com/lit/zip/spruil1

Cc: stable@vger.kernel.org
Fixes: 7a343c8bf4b5 ("phy: Add Cadence D-PHY support")
Signed-off-by: Devarsh Thakkar <devarsht@ti.com>
Tested-by: Harikrishna Shenoy <h-shenoy@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://lore.kernel.org/r/20250704125915.1224738-2-devarsht@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
index 33a42e72362e..da8de0a9d086 100644
--- a/drivers/phy/cadence/cdns-dphy.c
+++ b/drivers/phy/cadence/cdns-dphy.c
@@ -92,6 +92,8 @@ struct cdns_dphy_ops {
 	void (*set_pll_cfg)(struct cdns_dphy *dphy,
 			    const struct cdns_dphy_cfg *cfg);
 	unsigned long (*get_wakeup_time_ns)(struct cdns_dphy *dphy);
+	int (*wait_for_pll_lock)(struct cdns_dphy *dphy);
+	int (*wait_for_cmn_ready)(struct cdns_dphy *dphy);
 };
 
 struct cdns_dphy {
@@ -101,6 +103,8 @@ struct cdns_dphy {
 	struct clk *pll_ref_clk;
 	const struct cdns_dphy_ops *ops;
 	struct phy *phy;
+	bool is_configured;
+	bool is_powered;
 };
 
 /* Order of bands is important since the index is the band number. */
@@ -186,6 +190,16 @@ static unsigned long cdns_dphy_get_wakeup_time_ns(struct cdns_dphy *dphy)
 	return dphy->ops->get_wakeup_time_ns(dphy);
 }
 
+static int cdns_dphy_wait_for_pll_lock(struct cdns_dphy *dphy)
+{
+	return dphy->ops->wait_for_pll_lock ? dphy->ops->wait_for_pll_lock(dphy) : 0;
+}
+
+static int cdns_dphy_wait_for_cmn_ready(struct cdns_dphy *dphy)
+{
+	return  dphy->ops->wait_for_cmn_ready ? dphy->ops->wait_for_cmn_ready(dphy) : 0;
+}
+
 static unsigned long cdns_dphy_ref_get_wakeup_time_ns(struct cdns_dphy *dphy)
 {
 	/* Default wakeup time is 800 ns (in a simulated environment). */
@@ -227,7 +241,6 @@ static unsigned long cdns_dphy_j721e_get_wakeup_time_ns(struct cdns_dphy *dphy)
 static void cdns_dphy_j721e_set_pll_cfg(struct cdns_dphy *dphy,
 					const struct cdns_dphy_cfg *cfg)
 {
-	u32 status;
 
 	/*
 	 * set the PWM and PLL Byteclk divider settings to recommended values
@@ -244,13 +257,6 @@ static void cdns_dphy_j721e_set_pll_cfg(struct cdns_dphy *dphy,
 
 	writel(DPHY_TX_J721E_WIZ_LANE_RSTB,
 	       dphy->regs + DPHY_TX_J721E_WIZ_RST_CTRL);
-
-	readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL, status,
-			   (status & DPHY_TX_WIZ_PLL_LOCK), 0, POLL_TIMEOUT_US);
-
-	readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_STATUS, status,
-			   (status & DPHY_TX_WIZ_O_CMN_READY), 0,
-			   POLL_TIMEOUT_US);
 }
 
 static void cdns_dphy_j721e_set_psm_div(struct cdns_dphy *dphy, u8 div)
@@ -258,6 +264,23 @@ static void cdns_dphy_j721e_set_psm_div(struct cdns_dphy *dphy, u8 div)
 	writel(div, dphy->regs + DPHY_TX_J721E_WIZ_PSM_FREQ);
 }
 
+static int cdns_dphy_j721e_wait_for_pll_lock(struct cdns_dphy *dphy)
+{
+	u32 status;
+
+	return readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL, status,
+			       status & DPHY_TX_WIZ_PLL_LOCK, 0, POLL_TIMEOUT_US);
+}
+
+static int cdns_dphy_j721e_wait_for_cmn_ready(struct cdns_dphy *dphy)
+{
+	u32 status;
+
+	return readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_STATUS, status,
+			       status & DPHY_TX_WIZ_O_CMN_READY, 0,
+			       POLL_TIMEOUT_US);
+}
+
 /*
  * This is the reference implementation of DPHY hooks. Specific integration of
  * this IP may have to re-implement some of them depending on how they decided
@@ -273,6 +296,8 @@ static const struct cdns_dphy_ops j721e_dphy_ops = {
 	.get_wakeup_time_ns = cdns_dphy_j721e_get_wakeup_time_ns,
 	.set_pll_cfg = cdns_dphy_j721e_set_pll_cfg,
 	.set_psm_div = cdns_dphy_j721e_set_psm_div,
+	.wait_for_pll_lock = cdns_dphy_j721e_wait_for_pll_lock,
+	.wait_for_cmn_ready = cdns_dphy_j721e_wait_for_cmn_ready,
 };
 
 static int cdns_dphy_config_from_opts(struct phy *phy,
@@ -328,21 +353,36 @@ static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
 static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
 {
 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
-	struct cdns_dphy_cfg cfg = { 0 };
-	int ret, band_ctrl;
-	unsigned int reg;
+	int ret;
 
-	ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
-	if (ret)
-		return ret;
+	ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &dphy->cfg);
+	if (!ret)
+		dphy->is_configured = true;
+
+	return ret;
+}
+
+static int cdns_dphy_power_on(struct phy *phy)
+{
+	struct cdns_dphy *dphy = phy_get_drvdata(phy);
+	int ret;
+	u32 reg;
+
+	if (!dphy->is_configured || dphy->is_powered)
+		return -EINVAL;
+
+	clk_prepare_enable(dphy->psm_clk);
+	clk_prepare_enable(dphy->pll_ref_clk);
 
 	/*
 	 * Configure the internal PSM clk divider so that the DPHY has a
 	 * 1MHz clk (or something close).
 	 */
 	ret = cdns_dphy_setup_psm(dphy);
-	if (ret)
-		return ret;
+	if (ret) {
+		dev_err(&dphy->phy->dev, "Failed to setup PSM with error %d\n", ret);
+		goto err_power_on;
+	}
 
 	/*
 	 * Configure attach clk lanes to data lanes: the DPHY has 2 clk lanes
@@ -357,40 +397,60 @@ static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
 	 * Configure the DPHY PLL that will be used to generate the TX byte
 	 * clk.
 	 */
-	cdns_dphy_set_pll_cfg(dphy, &cfg);
+	cdns_dphy_set_pll_cfg(dphy, &dphy->cfg);
 
-	band_ctrl = cdns_dphy_tx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
-	if (band_ctrl < 0)
-		return band_ctrl;
+	ret = cdns_dphy_tx_get_band_ctrl(dphy->cfg.hs_clk_rate);
+	if (ret < 0) {
+		dev_err(&dphy->phy->dev, "Failed to get band control value with error %d\n", ret);
+		goto err_power_on;
+	}
 
-	reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
-	      FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
+	reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, ret) |
+	      FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, ret);
 	writel(reg, dphy->regs + DPHY_BAND_CFG);
 
-	return 0;
-}
-
-static int cdns_dphy_power_on(struct phy *phy)
-{
-	struct cdns_dphy *dphy = phy_get_drvdata(phy);
-
-	clk_prepare_enable(dphy->psm_clk);
-	clk_prepare_enable(dphy->pll_ref_clk);
-
 	/* Start TX state machine. */
 	writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN,
 	       dphy->regs + DPHY_CMN_SSM);
 
+	ret = cdns_dphy_wait_for_pll_lock(dphy);
+	if (ret) {
+		dev_err(&dphy->phy->dev, "Failed to lock PLL with error %d\n", ret);
+		goto err_power_on;
+	}
+
+	ret = cdns_dphy_wait_for_cmn_ready(dphy);
+	if (ret) {
+		dev_err(&dphy->phy->dev, "O_CMN_READY signal failed to assert with error %d\n",
+			ret);
+		goto err_power_on;
+	}
+
+	dphy->is_powered = true;
+
 	return 0;
+
+err_power_on:
+	clk_disable_unprepare(dphy->pll_ref_clk);
+	clk_disable_unprepare(dphy->psm_clk);
+
+	return ret;
 }
 
 static int cdns_dphy_power_off(struct phy *phy)
 {
 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
+	u32 reg;
 
 	clk_disable_unprepare(dphy->pll_ref_clk);
 	clk_disable_unprepare(dphy->psm_clk);
 
+	/* Stop TX state machine. */
+	reg = readl(dphy->regs + DPHY_CMN_SSM);
+	writel(reg & ~DPHY_CMN_SSM_EN, dphy->regs + DPHY_CMN_SSM);
+
+	dphy->is_powered = false;
+
 	return 0;
 }
 


^ permalink raw reply related	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2025-10-20 13:00 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-10-16 13:06 FAILED: patch "[PATCH] phy: cadence: cdns-dphy: Fix PLL lock and O_CMN_READY polling" failed to apply to 6.1-stable tree gregkh
2025-10-20 12:59 ` [PATCH 6.1.y 1/2] phy: cdns-dphy: Store hs_clk_rate and return it Sasha Levin
2025-10-20 12:59   ` [PATCH 6.1.y 2/2] phy: cadence: cdns-dphy: Fix PLL lock and O_CMN_READY polling Sasha Levin

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.