Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux

Pull clk updates from Stephen Boyd:
 "The large diff this time around is from the addition of a new clk
  driver for the TI Davinci family of SoCs. So far those clks have been
  supported with a custom implementation of the clk API in the arch port
  instead of in the CCF. With this driver merged we're one step closer
  to having a single clk API implementation.

  The other large diff is from the Amlogic clk driver that underwent
  some major surgery to use regmap. Beyond that, the biggest hitter is
  Samsung which needed some reworks to properly handle clk provider
  power domains and a bunch of PLL rate updates.

  The core framework was fairly quiet this round, just getting some
  cleanups and small fixes for some of the more esoteric features. And
  the usual set of driver non-critical fixes, cleanups, and minor
  additions are here as well.

  Core:
   - Rejig clk_ops::init() to be a little earlier for phase/accuracy ops
   - debugfs ops macroized to shave some lines of boilerplate code
   - Always calculate the phase instead of caching it in clk_get_phase()
   - More __must_check on bulk clk APIs

  New Drivers:
   - TI's Davinci family of SoCs
   - Intel's Stratix10 SoC
   - stm32mp157 SoC
   - Allwinner H6 CCU
   - Silicon Labs SI544 clock generator chip
   - Renesas R-Car M3-N and V3H SoCs
   - i.MX6SLL SoCs

  Removed Drivers:
   - ST-Ericsson AB8540/9540

  Updates:
   - Mediatek MT2701 and MT7622 audsys support and MT2712 updates
   - STM32F469 DSI and STM32F769 sdmmc2 support
   - GPIO clks can sleep now
   - Spreadtrum SC9860 RTC clks
   - Nvidia Tegra MBIST workarounds and various minor fixes
   - Rockchip phase handling fixes and a memory leak plugged
   - Renesas drivers switch to readl/writel from clk_readl/clk_writel
   - Renesas gained CPU (Z/Z2) and watchdog support
   - Rockchip rk3328 display clks and rk3399 1.6GHz PLL support
   - Qualcomm PM8921 PMIC XO buffers
   - Amlogic migrates to regmap APIs
   - TI Keystone clk latching support
   - Allwinner H3 and H5 video clk fixes
   - Broadcom BCM2835 PLLs needed another bit to enable
   - i.MX6SX CKO mux fix and i.MX7D Video PLL divider fix
   - i.MX6UL/ULL epdc_podf support
   - Hi3798CV200 COMBPHY0 and USB2_OTG_UTMI and phase support for eMMC"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (233 commits)
  clk: davinci: add a reset lookup table for psc0
  clk: imx: add clock driver for imx6sll
  dt-bindings: imx: update clock doc for imx6sll
  clk: imx: add new gate/gate2 wrapper funtion
  clk: imx: Add CLK_IS_CRITICAL flag for busy divider and busy mux
  clk: cs2000: set pm_ops in hibernate-compatible way
  clk: bcm2835: De-assert/assert PLL reset signal when appropriate
  clk: imx7d: Move clks_init_on before any clock operations
  clk: imx7d: Correct ahb clk parent select
  clk: imx7d: Correct dram pll type
  clk: imx7d: Add USB clock information
  clk: socfpga: stratix10: add clock driver for Stratix10 platform
  dt-bindings: documentation: add clock bindings information for Stratix10
  clk: ti: fix flag space conflict with clkctrl clocks
  clk: uniphier: add additional ethernet clock lines for Pro4
  clk: uniphier: add SATA clock control support
  clk: uniphier: add PCIe clock control support
  clk: Add driver for the si544 clock generator chip
  clk: davinci: Remove redundant dev_err calls
  clk: uniphier: add ethernet clock control support for PXs3
  ...

1 files changed, 76 insertions, 2 deletions

diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c
index 077fcdc7908b..026a26bb702d 100644
--- a/drivers/clk/rockchip/clk-mmc-phase.c
+++ b/drivers/clk/rockchip/clk-mmc-phase.c
@@ -25,6 +25,8 @@ struct rockchip_mmc_clock {
 	void __iomem	*reg;
 	int		id;
 	int		shift;
+	int		cached_phase;
+	struct notifier_block clk_rate_change_nb;
 };
 
 #define to_mmc_clock(_hw) container_of(_hw, struct rockchip_mmc_clock, hw)
@@ -58,6 +60,12 @@ static int rockchip_mmc_get_phase(struct clk_hw *hw)
 	u16 degrees;
 	u32 delay_num = 0;
 
+	/* See the comment for rockchip_mmc_set_phase below */
+	if (!rate) {
+		pr_err("%s: invalid clk rate\n", __func__);
+		return -EINVAL;
+	}
+
 	raw_value = readl(mmc_clock->reg) >> (mmc_clock->shift);
 
 	degrees = (raw_value & ROCKCHIP_MMC_DEGREE_MASK) * 90;
@@ -84,6 +92,23 @@ static int rockchip_mmc_set_phase(struct clk_hw *hw, int degrees)
 	u32 raw_value;
 	u32 delay;
 
+	/*
+	 * The below calculation is based on the output clock from
+	 * MMC host to the card, which expects the phase clock inherits
+	 * the clock rate from its parent, namely the output clock
+	 * provider of MMC host. However, things may go wrong if
+	 * (1) It is orphan.
+	 * (2) It is assigned to the wrong parent.
+	 *
+	 * This check help debug the case (1), which seems to be the
+	 * most likely problem we often face and which makes it difficult
+	 * for people to debug unstable mmc tuning results.
+	 */
+	if (!rate) {
+		pr_err("%s: invalid clk rate\n", __func__);
+		return -EINVAL;
+	}
+
 	nineties = degrees / 90;
 	remainder = (degrees % 90);
 
@@ -139,6 +164,41 @@ static const struct clk_ops rockchip_mmc_clk_ops = {
 	.set_phase	= rockchip_mmc_set_phase,
 };
 
+#define to_rockchip_mmc_clock(x) \
+	container_of(x, struct rockchip_mmc_clock, clk_rate_change_nb)
+static int rockchip_mmc_clk_rate_notify(struct notifier_block *nb,
+					unsigned long event, void *data)
+{
+	struct rockchip_mmc_clock *mmc_clock = to_rockchip_mmc_clock(nb);
+	struct clk_notifier_data *ndata = data;
+
+	/*
+	 * rockchip_mmc_clk is mostly used by mmc controllers to sample
+	 * the intput data, which expects the fixed phase after the tuning
+	 * process. However if the clock rate is changed, the phase is stale
+	 * and may break the data sampling. So here we try to restore the phase
+	 * for that case, except that
+	 * (1) cached_phase is invaild since we inevitably cached it when the
+	 * clock provider be reparented from orphan to its real parent in the
+	 * first place. Otherwise we may mess up the initialization of MMC cards
+	 * since we only set the default sample phase and drive phase later on.
+	 * (2) the new coming rate is higher than the older one since mmc driver
+	 * set the max-frequency to match the boards' ability but we can't go
+	 * over the heads of that, otherwise the tests smoke out the issue.
+	 */
+	if (ndata->old_rate <= ndata->new_rate)
+		return NOTIFY_DONE;
+
+	if (event == PRE_RATE_CHANGE)
+		mmc_clock->cached_phase =
+			rockchip_mmc_get_phase(&mmc_clock->hw);
+	else if (mmc_clock->cached_phase != -EINVAL &&
+		 event == POST_RATE_CHANGE)
+		rockchip_mmc_set_phase(&mmc_clock->hw, mmc_clock->cached_phase);
+
+	return NOTIFY_DONE;
+}
+
 struct clk *rockchip_clk_register_mmc(const char *name,
 				const char *const *parent_names, u8 num_parents,
 				void __iomem *reg, int shift)
@@ -146,6 +206,7 @@ struct clk *rockchip_clk_register_mmc(const char *name,
 	struct clk_init_data init;
 	struct rockchip_mmc_clock *mmc_clock;
 	struct clk *clk;
+	int ret;
 
 	mmc_clock = kmalloc(sizeof(*mmc_clock), GFP_KERNEL);
 	if (!mmc_clock)
@@ -162,8 +223,21 @@ struct clk *rockchip_clk_register_mmc(const char *name,
 	mmc_clock->shift = shift;
 
 	clk = clk_register(NULL, &mmc_clock->hw);
-	if (IS_ERR(clk))
-		kfree(mmc_clock);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto err_register;
+	}
+
+	mmc_clock->clk_rate_change_nb.notifier_call =
+				&rockchip_mmc_clk_rate_notify;
+	ret = clk_notifier_register(clk, &mmc_clock->clk_rate_change_nb);
+	if (ret)
+		goto err_notifier;
 
 	return clk;
+err_notifier:
+	clk_unregister(clk);
+err_register:
+	kfree(mmc_clock);
+	return ERR_PTR(ret);
 }