6.6-stable review patch. If anyone has any objections, please let me know.
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From: Devarsh Thakkar devarsht@ti.com
[ Upstream commit 284fb19a3ffb1083c3ad9c00d29749d09dddb99c ]
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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/phy/cadence/cdns-dphy.c | 124 +++++++++++++++++++++++++++++----------- 1 file changed, 92 insertions(+), 32 deletions(-)
--- a/drivers/phy/cadence/cdns-dphy.c +++ b/drivers/phy/cadence/cdns-dphy.c @@ -100,6 +100,8 @@ 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 { @@ -109,6 +111,8 @@ 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. */ @@ -195,6 +199,16 @@ static unsigned long cdns_dphy_get_wakeu 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). */ @@ -236,7 +250,6 @@ static unsigned long cdns_dphy_j721e_get 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 @@ -253,13 +266,6 @@ static void cdns_dphy_j721e_set_pll_cfg(
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) @@ -267,6 +273,23 @@ static void cdns_dphy_j721e_set_psm_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 @@ -282,6 +305,8 @@ static const struct cdns_dphy_ops j721e_ .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, @@ -339,21 +364,36 @@ static int cdns_dphy_validate(struct phy 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 @@ -368,40 +408,60 @@ static int cdns_dphy_configure(struct ph * 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; }