Merge tag 'for-5.17-clk' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into clk-nvidia

bebarino · bebarino · commit fcfc6ea4a400 · 2021-12-28T21:47:05.000-08:00
Pull Tegra clk driver updates from Thierry Reding:

This contains a simple fix for the VDE clock on Tegra114 and some
preparation work to support runtime PM and generic power domains.

* tag 'for-5.17-clk' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  clk: tegra: Support runtime PM and power domain
  clk: tegra: Make vde a child of pll_p on tegra114
diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-y					+= clk.o
 obj-y					+= clk-audio-sync.o
+obj-y					+= clk-device.o
 obj-y					+= clk-dfll.o
 obj-y					+= clk-divider.o
 obj-y					+= clk-periph.o
diff --git a/drivers/clk/tegra/clk-device.c b/drivers/clk/tegra/clk-device.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_opp.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#include <soc/tegra/common.h>
+
+#include "clk.h"
+
+/*
+ * This driver manages performance state of the core power domain for the
+ * independent PLLs and system clocks.  We created a virtual clock device
+ * for such clocks, see tegra_clk_dev_register().
+ */
+
+struct tegra_clk_device {
+	struct notifier_block clk_nb;
+	struct device *dev;
+	struct clk_hw *hw;
+	struct mutex lock;
+};
+
+static int tegra_clock_set_pd_state(struct tegra_clk_device *clk_dev,
+				    unsigned long rate)
+{
+	struct device *dev = clk_dev->dev;
+	struct dev_pm_opp *opp;
+	unsigned int pstate;
+
+	opp = dev_pm_opp_find_freq_ceil(dev, &rate);
+	if (opp == ERR_PTR(-ERANGE)) {
+		/*
+		 * Some clocks may be unused by a particular board and they
+		 * may have uninitiated clock rate that is overly high.  In
+		 * this case clock is expected to be disabled, but still we
+		 * need to set up performance state of the power domain and
+		 * not error out clk initialization.  A typical example is
+		 * a PCIe clock on Android tablets.
+		 */
+		dev_dbg(dev, "failed to find ceil OPP for %luHz\n", rate);
+		opp = dev_pm_opp_find_freq_floor(dev, &rate);
+	}
+
+	if (IS_ERR(opp)) {
+		dev_err(dev, "failed to find OPP for %luHz: %pe\n", rate, opp);
+		return PTR_ERR(opp);
+	}
+
+	pstate = dev_pm_opp_get_required_pstate(opp, 0);
+	dev_pm_opp_put(opp);
+
+	return dev_pm_genpd_set_performance_state(dev, pstate);
+}
+
+static int tegra_clock_change_notify(struct notifier_block *nb,
+				     unsigned long msg, void *data)
+{
+	struct clk_notifier_data *cnd = data;
+	struct tegra_clk_device *clk_dev;
+	int err = 0;
+
+	clk_dev = container_of(nb, struct tegra_clk_device, clk_nb);
+
+	mutex_lock(&clk_dev->lock);
+	switch (msg) {
+	case PRE_RATE_CHANGE:
+		if (cnd->new_rate > cnd->old_rate)
+			err = tegra_clock_set_pd_state(clk_dev, cnd->new_rate);
+		break;
+
+	case ABORT_RATE_CHANGE:
+		err = tegra_clock_set_pd_state(clk_dev, cnd->old_rate);
+		break;
+
+	case POST_RATE_CHANGE:
+		if (cnd->new_rate < cnd->old_rate)
+			err = tegra_clock_set_pd_state(clk_dev, cnd->new_rate);
+		break;
+
+	default:
+		break;
+	}
+	mutex_unlock(&clk_dev->lock);
+
+	return notifier_from_errno(err);
+}
+
+static int tegra_clock_sync_pd_state(struct tegra_clk_device *clk_dev)
+{
+	unsigned long rate;
+	int ret;
+
+	mutex_lock(&clk_dev->lock);
+
+	rate = clk_hw_get_rate(clk_dev->hw);
+	ret = tegra_clock_set_pd_state(clk_dev, rate);
+
+	mutex_unlock(&clk_dev->lock);
+
+	return ret;
+}
+
+static int tegra_clock_probe(struct platform_device *pdev)
+{
+	struct tegra_core_opp_params opp_params = {};
+	struct tegra_clk_device *clk_dev;
+	struct device *dev = &pdev->dev;
+	struct clk *clk;
+	int err;
+
+	if (!dev->pm_domain)
+		return -EINVAL;
+
+	clk_dev = devm_kzalloc(dev, sizeof(*clk_dev), GFP_KERNEL);
+	if (!clk_dev)
+		return -ENOMEM;
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	clk_dev->dev = dev;
+	clk_dev->hw = __clk_get_hw(clk);
+	clk_dev->clk_nb.notifier_call = tegra_clock_change_notify;
+	mutex_init(&clk_dev->lock);
+
+	platform_set_drvdata(pdev, clk_dev);
+
+	/*
+	 * Runtime PM was already enabled for this device by the parent clk
+	 * driver and power domain state should be synced under clk_dev lock,
+	 * hence we don't use the common OPP helper that initializes OPP
+	 * state. For some clocks common OPP helper may fail to find ceil
+	 * rate, it's handled by this driver.
+	 */
+	err = devm_tegra_core_dev_init_opp_table(dev, &opp_params);
+	if (err)
+		return err;
+
+	err = clk_notifier_register(clk, &clk_dev->clk_nb);
+	if (err) {
+		dev_err(dev, "failed to register clk notifier: %d\n", err);
+		return err;
+	}
+
+	/*
+	 * The driver is attaching to a potentially active/resumed clock, hence
+	 * we need to sync the power domain performance state in a accordance to
+	 * the clock rate if clock is resumed.
+	 */
+	err = tegra_clock_sync_pd_state(clk_dev);
+	if (err)
+		goto unreg_clk;
+
+	return 0;
+
+unreg_clk:
+	clk_notifier_unregister(clk, &clk_dev->clk_nb);
+
+	return err;
+}
+
+/*
+ * Tegra GENPD driver enables clocks during NOIRQ phase. It can't be done
+ * for clocks served by this driver because runtime PM is unavailable in
+ * NOIRQ phase. We will keep clocks resumed during suspend to mitigate this
+ * problem. In practice this makes no difference from a power management
+ * perspective since voltage is kept at a nominal level during suspend anyways.
+ */
+static const struct dev_pm_ops tegra_clock_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_resume_and_get, pm_runtime_put)
+};
+
+static const struct of_device_id tegra_clock_match[] = {
+	{ .compatible = "nvidia,tegra20-sclk" },
+	{ .compatible = "nvidia,tegra30-sclk" },
+	{ .compatible = "nvidia,tegra30-pllc" },
+	{ .compatible = "nvidia,tegra30-plle" },
+	{ .compatible = "nvidia,tegra30-pllm" },
+	{ }
+};
+
+static struct platform_driver tegra_clock_driver = {
+	.driver = {
+		.name = "tegra-clock",
+		.of_match_table = tegra_clock_match,
+		.pm = &tegra_clock_pm,
+		.suppress_bind_attrs = true,
+	},
+	.probe = tegra_clock_probe,
+};
+builtin_platform_driver(tegra_clock_driver);
diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
@@ -1914,7 +1914,7 @@ static struct clk *_tegra_clk_register_pll(struct tegra_clk_pll *pll,
 	/* Data in .init is copied by clk_register(), so stack variable OK */
 	pll->hw.init = &init;
 
-	return clk_register(NULL, &pll->hw);
+	return tegra_clk_dev_register(&pll->hw);
 }
 
 struct clk *tegra_clk_register_pll(const char *name, const char *parent_name,
diff --git a/drivers/clk/tegra/clk-super.c b/drivers/clk/tegra/clk-super.c
@@ -226,7 +226,7 @@ struct clk *tegra_clk_register_super_mux(const char *name,
 	/* Data in .init is copied by clk_register(), so stack variable OK */
 	super->hw.init = &init;
 
-	clk = clk_register(NULL, &super->hw);
+	clk = tegra_clk_dev_register(&super->hw);
 	if (IS_ERR(clk))
 		kfree(super);
 
diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c
@@ -1158,7 +1158,7 @@ static struct tegra_clk_init_table init_table[] __initdata = {
 	{ TEGRA114_CLK_XUSB_HS_SRC, TEGRA114_CLK_XUSB_SS_DIV2, 61200000, 0 },
 	{ TEGRA114_CLK_XUSB_FALCON_SRC, TEGRA114_CLK_PLL_P, 204000000, 0 },
 	{ TEGRA114_CLK_XUSB_HOST_SRC, TEGRA114_CLK_PLL_P, 102000000, 0 },
-	{ TEGRA114_CLK_VDE, TEGRA114_CLK_CLK_MAX, 600000000, 0 },
+	{ TEGRA114_CLK_VDE, TEGRA114_CLK_PLL_P, 408000000, 0 },
 	{ TEGRA114_CLK_SPDIF_IN_SYNC, TEGRA114_CLK_CLK_MAX, 24000000, 0 },
 	{ TEGRA114_CLK_I2S0_SYNC, TEGRA114_CLK_CLK_MAX, 24000000, 0 },
 	{ TEGRA114_CLK_I2S1_SYNC, TEGRA114_CLK_CLK_MAX, 24000000, 0 },
diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c
@@ -6,8 +6,11 @@
 #include <linux/io.h>
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
+#include <linux/init.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
 #include <linux/clk/tegra.h>
 #include <linux/delay.h>
 #include <dt-bindings/clock/tegra20-car.h>
@@ -414,7 +417,7 @@ static struct tegra_clk_pll_params pll_e_params = {
 	.fixed_rate = 100000000,
 };
 
-static struct tegra_devclk devclks[] __initdata = {
+static struct tegra_devclk devclks[] = {
 	{ .con_id = "pll_c", .dt_id = TEGRA20_CLK_PLL_C },
 	{ .con_id = "pll_c_out1", .dt_id = TEGRA20_CLK_PLL_C_OUT1 },
 	{ .con_id = "pll_p", .dt_id = TEGRA20_CLK_PLL_P },
@@ -710,13 +713,6 @@ static void tegra20_super_clk_init(void)
 			      NULL);
 	clks[TEGRA20_CLK_CCLK] = clk;
 
-	/* SCLK */
-	clk = tegra_clk_register_super_mux("sclk", sclk_parents,
-			      ARRAY_SIZE(sclk_parents),
-			      CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
-			      clk_base + SCLK_BURST_POLICY, 0, 4, 0, 0, NULL);
-	clks[TEGRA20_CLK_SCLK] = clk;
-
 	/* twd */
 	clk = clk_register_fixed_factor(NULL, "twd", "cclk", 0, 1, 4);
 	clks[TEGRA20_CLK_TWD] = clk;
@@ -1014,7 +1010,7 @@ static struct tegra_cpu_car_ops tegra20_cpu_car_ops = {
 #endif
 };
 
-static struct tegra_clk_init_table init_table[] __initdata = {
+static struct tegra_clk_init_table init_table[] = {
 	{ TEGRA20_CLK_PLL_P, TEGRA20_CLK_CLK_MAX, 216000000, 1 },
 	{ TEGRA20_CLK_PLL_P_OUT1, TEGRA20_CLK_CLK_MAX, 28800000, 1 },
 	{ TEGRA20_CLK_PLL_P_OUT2, TEGRA20_CLK_CLK_MAX, 48000000, 1 },
@@ -1052,11 +1048,6 @@ static struct tegra_clk_init_table init_table[] __initdata = {
 	{ TEGRA20_CLK_CLK_MAX, TEGRA20_CLK_CLK_MAX, 0, 0 },
 };
 
-static void __init tegra20_clock_apply_init_table(void)
-{
-	tegra_init_from_table(init_table, clks, TEGRA20_CLK_CLK_MAX);
-}
-
 /*
  * Some clocks may be used by different drivers depending on the board
  * configuration.  List those here to register them twice in the clock lookup
@@ -1076,13 +1067,25 @@ static const struct of_device_id pmc_match[] __initconst = {
 	{ },
 };
 
+static bool tegra20_car_initialized;
+
 static struct clk *tegra20_clk_src_onecell_get(struct of_phandle_args *clkspec,
 					       void *data)
 {
 	struct clk_hw *parent_hw;
 	struct clk_hw *hw;
 	struct clk *clk;
 
+	/*
+	 * Timer clocks are needed early, the rest of the clocks shouldn't be
+	 * available to device drivers until clock tree is fully initialized.
+	 */
+	if (clkspec->args[0] != TEGRA20_CLK_RTC &&
+	    clkspec->args[0] != TEGRA20_CLK_TWD &&
+	    clkspec->args[0] != TEGRA20_CLK_TIMER &&
+	    !tegra20_car_initialized)
+		return ERR_PTR(-EPROBE_DEFER);
+
 	clk = of_clk_src_onecell_get(clkspec, data);
 	if (IS_ERR(clk))
 		return clk;
@@ -1149,10 +1152,48 @@ static void __init tegra20_clock_init(struct device_node *np)
 	tegra_init_dup_clks(tegra_clk_duplicates, clks, TEGRA20_CLK_CLK_MAX);
 
 	tegra_add_of_provider(np, tegra20_clk_src_onecell_get);
-	tegra_register_devclks(devclks, ARRAY_SIZE(devclks));
-
-	tegra_clk_apply_init_table = tegra20_clock_apply_init_table;
 
 	tegra_cpu_car_ops = &tegra20_cpu_car_ops;
 }
-CLK_OF_DECLARE(tegra20, "nvidia,tegra20-car", tegra20_clock_init);
+CLK_OF_DECLARE_DRIVER(tegra20, "nvidia,tegra20-car", tegra20_clock_init);
+
+/*
+ * Clocks that use runtime PM can't be created at the tegra20_clock_init
+ * time because drivers' base isn't initialized yet, and thus platform
+ * devices can't be created for the clocks.  Hence we need to split the
+ * registration of the clocks into two phases.  The first phase registers
+ * essential clocks which don't require RPM and are actually used during
+ * early boot.  The second phase registers clocks which use RPM and this
+ * is done when device drivers' core API is ready.
+ */
+static int tegra20_car_probe(struct platform_device *pdev)
+{
+	struct clk *clk;
+
+	clk = tegra_clk_register_super_mux("sclk", sclk_parents,
+			      ARRAY_SIZE(sclk_parents),
+			      CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
+			      clk_base + SCLK_BURST_POLICY, 0, 4, 0, 0, NULL);
+	clks[TEGRA20_CLK_SCLK] = clk;
+
+	tegra_register_devclks(devclks, ARRAY_SIZE(devclks));
+	tegra_init_from_table(init_table, clks, TEGRA20_CLK_CLK_MAX);
+	tegra20_car_initialized = true;
+
+	return 0;
+}
+
+static const struct of_device_id tegra20_car_match[] = {
+	{ .compatible = "nvidia,tegra20-car" },
+	{ }
+};
+
+static struct platform_driver tegra20_car_driver = {
+	.driver = {
+		.name = "tegra20-car",
+		.of_match_table = tegra20_car_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = tegra20_car_probe,
+};
+builtin_platform_driver(tegra20_car_driver);
diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c
diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h

Original file line number	Diff line number	Diff line change
`@@ -1914,7 +1914,7 @@ static struct clk _tegra_clk_register_pll(struct tegra_clk_pll pll,`
`1914`	`1914`	`/* Data in .init is copied by clk_register(), so stack variable OK */`
`1915`	`1915`	`pll->hw.init = &init;`
`1916`	`1916`
`1917`		`- return clk_register(NULL, &pll->hw);`
	`1917`	`+ return tegra_clk_dev_register(&pll->hw);`
`1918`	`1918`	`}`
`1919`	`1919`
`1920`	`1920`	`struct clk tegra_clk_register_pll(const char name, const char *parent_name,`