[PATCH v4 00/10] NVIDIA Tegra20 CPUFreq driver major update

[PATCH v4 00/10] NVIDIA Tegra20 CPUFreq driver major update

[Dmitry Osipenko]

Hello,

This series moves intermediate-clk handling from tegra20-cpufreq into
tegra-clk driver. This allows us to switch to generic cpufreq-dt driver
which brings voltage scaling, per-hardware OPPs and Tegra30 support out
of the box. All boards need to adopt CPU OPPs in their device-trees in
order to get cpufreq support.

Changelog:

v4: - Updated CCLK diagram in the "Add custom CCLK implementation" patch.

    - <linux/cpu.h> is now included in the "Use generic cpufreq-dt driver"
      patch, for consistency.

    - Returned value of get_cpu_device() is now checked in the "Use generic
      cpufreq-dt driver" patch, for consistency as well.

v3: - The "Add custom CCLK implementation" patch was updated in accordance
      to the comments from Peter De Schrijver. We will not use the clock
      skipper.

    - Re added OPPs for T30 Beaver board because Thierry has that board ;)

    - Added r-b for the "DT binding" patch from Rob Herring.

v2: - Kept modularity of the tegra20-cpufreq as was requested by Viresh Kumar
      in a review comment to v1.

    - Added acks from Viresh Kumar.

    - Added tested-by from Nicolas Chauvet to the "trimslice" patch.
      Nicolas told me on IRC that it works fine.

    - Fixed compilation of the "Add custom CCLK implementation" patch. The
      error happened because v1 was based on top of yet unreviewed/unapplied
      patch "clk: tegra: divider: Support enable-bit for Super clocks".
      Thanks to Peter Geis for reporting the problem.

    - Replaced Tegra30 "beaver" board with "cardhu-a04" because turned out
      that's what NVIDIA uses in the testing farm.

Dmitry Osipenko (10):
  clk: tegra: Add custom CCLK implementation
  clk: tegra: pll: Add pre/post rate-change hooks
  clk: tegra: cclk: Add helpers for handling PLLX rate changes
  clk: tegra20: Use custom CCLK implementation
  clk: tegra30: Use custom CCLK implementation
  dt-bindings: cpufreq: Add binding for NVIDIA Tegra20/30
  cpufreq: tegra20: Use generic cpufreq-dt driver (Tegra30 supported
    now)
  ARM: tegra: Create tegra20-cpufreq platform device on Tegra30
  ARM: dts: tegra30: beaver: Set up voltage regulators for DVFS
  ARM: dts: tegra30: beaver: Add CPU Operating Performance Points

 .../cpufreq/nvidia,tegra20-cpufreq.txt        |  56 +++++
 arch/arm/boot/dts/tegra30-beaver.dts          |  40 +++-
 arch/arm/mach-tegra/tegra.c                   |   4 +
 drivers/clk/tegra/Makefile                    |   1 +
 drivers/clk/tegra/clk-pll.c                   |  12 +-
 drivers/clk/tegra/clk-tegra-super-cclk.c      | 212 +++++++++++++++++
 drivers/clk/tegra/clk-tegra20.c               |   7 +-
 drivers/clk/tegra/clk-tegra30.c               |   6 +-
 drivers/clk/tegra/clk.h                       |  19 +-
 drivers/cpufreq/Kconfig.arm                   |   6 +-
 drivers/cpufreq/cpufreq-dt-platdev.c          |   2 +
 drivers/cpufreq/tegra20-cpufreq.c             | 217 +++++-------------
 12 files changed, 408 insertions(+), 174 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
 create mode 100644 drivers/clk/tegra/clk-tegra-super-cclk.c

-- 
2.23.0

[PATCH v4 01/10] clk: tegra: Add custom CCLK implementation

[Dmitry Osipenko]

CCLK stands for "CPU Clock", CPU core is running off CCLK. CCLK supports
multiple parents, it has internal clock divider and a clock skipper.
PLLX is the main CCLK parent that provides clock rates above 1GHz and it
has special property such that the CCLK's internal divider is set into
bypass mode when PLLX is selected as a parent for CCLK.

This patch forks generic Super Clock into CCLK implementation which takes
into account all CCLK specifics. The proper CCLK implementation is needed
by the upcoming Tegra20 CPUFreq driver update that will allow to utilize
the generic cpufreq-dt driver by moving intermediate clock selection into
the clock driver.

Note that technically this patch could be squashed into clk-super.c, but
it is cleaner to have a separate source file. Also note that currently all
CCLKLP bits are left in the clk-super.c and only CCLKG is supported by
clk-tegra-super-cclk. It shouldn't be difficult to move the CCLKLP bits,
but CCLKLP is not used by anything in kernel and thus better not to touch
it for now.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/Makefile               |   1 +
 drivers/clk/tegra/clk-tegra-super-cclk.c | 178 +++++++++++++++++++++++
 drivers/clk/tegra/clk.h                  |  11 +-
 3 files changed, 188 insertions(+), 2 deletions(-)
 create mode 100644 drivers/clk/tegra/clk-tegra-super-cclk.c

diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
index df966ca06788..f04b490f5416 100644
--- a/drivers/clk/tegra/Makefile
+++ b/drivers/clk/tegra/Makefile
@@ -14,6 +14,7 @@ obj-y					+= clk-tegra-audio.o
 obj-y					+= clk-tegra-periph.o
 obj-y					+= clk-tegra-pmc.o
 obj-y					+= clk-tegra-fixed.o
+obj-y					+= clk-tegra-super-cclk.o
 obj-y					+= clk-tegra-super-gen4.o
 obj-$(CONFIG_TEGRA_CLK_EMC)		+= clk-emc.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += clk-tegra20.o
diff --git a/drivers/clk/tegra/clk-tegra-super-cclk.c b/drivers/clk/tegra/clk-tegra-super-cclk.c
new file mode 100644
index 000000000000..7bcb9e8d0860
--- /dev/null
+++ b/drivers/clk/tegra/clk-tegra-super-cclk.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on clk-super.c
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Based on older tegra20-cpufreq driver by Colin Cross <ccross@google.com>
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author: Dmitry Osipenko <digetx@gmail.com>
+ * Copyright (C) 2019 GRATE-DRIVER project
+ */
+
+#include <linux/bits.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "clk.h"
+
+#define PLLP_INDEX		4
+#define PLLX_INDEX		8
+
+#define SUPER_CDIV_ENB		BIT(31)
+
+static u8 cclk_super_get_parent(struct clk_hw *hw)
+{
+	return tegra_clk_super_ops.get_parent(hw);
+}
+
+static int cclk_super_set_parent(struct clk_hw *hw, u8 index)
+{
+	return tegra_clk_super_ops.set_parent(hw, index);
+}
+
+static int cclk_super_set_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long parent_rate)
+{
+	return tegra_clk_super_ops.set_rate(hw, rate, parent_rate);
+}
+
+static unsigned long cclk_super_recalc_rate(struct clk_hw *hw,
+					    unsigned long parent_rate)
+{
+	if (cclk_super_get_parent(hw) == PLLX_INDEX)
+		return parent_rate;
+
+	return tegra_clk_super_ops.recalc_rate(hw, parent_rate);
+}
+
+static int cclk_super_determine_rate(struct clk_hw *hw,
+				     struct clk_rate_request *req)
+{
+	struct clk_hw *pllp_hw = clk_hw_get_parent_by_index(hw, PLLP_INDEX);
+	struct clk_hw *pllx_hw = clk_hw_get_parent_by_index(hw, PLLX_INDEX);
+	struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
+	unsigned long pllp_rate;
+	long rate = req->rate;
+
+	if (WARN_ON_ONCE(!pllp_hw || !pllx_hw))
+		return -EINVAL;
+
+	/*
+	 * Switch parent to PLLP for all CCLK rates that are suitable for PLLP.
+	 * PLLX will be disabled in this case, saving some power.
+	 */
+	pllp_rate = clk_hw_get_rate(pllp_hw);
+
+	if (rate <= pllp_rate) {
+		if (super->flags & TEGRA20_SUPER_CLK)
+			rate = pllp_rate;
+		else
+			rate = tegra_clk_super_ops.round_rate(hw, rate,
+							      &pllp_rate);
+
+		req->best_parent_rate = pllp_rate;
+		req->best_parent_hw = pllp_hw;
+		req->rate = rate;
+	} else {
+		rate = clk_hw_round_rate(pllx_hw, rate);
+		req->best_parent_rate = rate;
+		req->best_parent_hw = pllx_hw;
+		req->rate = rate;
+	}
+
+	if (WARN_ON_ONCE(rate <= 0))
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct clk_ops tegra_cclk_super_ops = {
+	.get_parent = cclk_super_get_parent,
+	.set_parent = cclk_super_set_parent,
+	.set_rate = cclk_super_set_rate,
+	.recalc_rate = cclk_super_recalc_rate,
+	.determine_rate = cclk_super_determine_rate,
+};
+
+static const struct clk_ops tegra_cclk_super_mux_ops = {
+	.get_parent = cclk_super_get_parent,
+	.set_parent = cclk_super_set_parent,
+	.determine_rate = cclk_super_determine_rate,
+};
+
+struct clk *tegra_clk_register_super_cclk(const char *name,
+		const char * const *parent_names, u8 num_parents,
+		unsigned long flags, void __iomem *reg, u8 clk_super_flags,
+		spinlock_t *lock)
+{
+	struct tegra_clk_super_mux *super;
+	struct clk *clk;
+	struct clk_init_data init;
+	u32 val;
+
+	super = kzalloc(sizeof(*super), GFP_KERNEL);
+	if (!super)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.flags = flags;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+
+	super->reg = reg;
+	super->lock = lock;
+	super->width = 4;
+	super->flags = clk_super_flags;
+	super->hw.init = &init;
+
+	if (super->flags & TEGRA20_SUPER_CLK) {
+		init.ops = &tegra_cclk_super_mux_ops;
+	} else {
+		init.ops = &tegra_cclk_super_ops;
+
+		super->frac_div.reg = reg + 4;
+		super->frac_div.shift = 16;
+		super->frac_div.width = 8;
+		super->frac_div.frac_width = 1;
+		super->frac_div.lock = lock;
+		super->div_ops = &tegra_clk_frac_div_ops;
+	}
+
+	/*
+	 * Tegra30+ has the following CPUG clock topology:
+	 *
+	 *        +---+  +-------+  +-+            +-+                +-+
+	 * PLLP+->+   +->+DIVIDER+->+0|  +-------->+0|  ------------->+0|
+	 *        |   |  +-------+  | |  |  +---+  | |  |             | |
+	 * PLLC+->+MUX|             | +->+  | S |  | +->+             | +->+CPU
+	 *  ...   |   |             | |  |  | K |  | |  |  +-------+  | |
+	 * PLLX+->+-->+------------>+1|  +->+ I +->+1|  +->+ DIV2  +->+1|
+	 *        +---+             +++     | P |  +++     |SKIPPER|  +++
+	 *                           ^      | P |   ^      +-------+   ^
+	 *                           |      | E |   |                  |
+	 *                PLLX_SEL+--+      | R |   |       OVERHEAT+--+
+	 *                                  +---+   |
+	 *                                          |
+	 *                         SUPER_CDIV_ENB+--+
+	 *
+	 * Tegra20 is similar, but simpler. It doesn't have the divider and
+	 * thermal DIV2 skipper.
+	 *
+	 * At least for now we're not going to use clock-skipper, hence let's
+	 * ensure that it is disabled.
+	 */
+	val = readl_relaxed(reg + 4);
+	val &= ~SUPER_CDIV_ENB;
+	writel_relaxed(val, reg + 4);
+
+	clk = clk_register(NULL, &super->hw);
+	if (IS_ERR(clk))
+		kfree(super);
+
+	return clk;
+}
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 416a6b09f6a3..ee35a847df08 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -729,8 +729,10 @@ struct clk *tegra_clk_register_periph_data(void __iomem *clk_base,
  * TEGRA_DIVIDER_2 - LP cluster has additional divider. This flag indicates
  *     that this is LP cluster clock.
  * TEGRA210_CPU_CLK - This flag is used to identify CPU cluster for gen5
- * super mux parent using PLLP branches. To use PLLP branches to CPU, need
- * to configure additional bit PLLP_OUT_CPU in the clock registers.
+ *     super mux parent using PLLP branches. To use PLLP branches to CPU, need
+ *     to configure additional bit PLLP_OUT_CPU in the clock registers.
+ * TEGRA20_SUPER_CLK - Tegra20 doesn't have a dedicated divider for Super
+ *     clocks, it only has a clock-skipper.
  */
 struct tegra_clk_super_mux {
 	struct clk_hw	hw;
@@ -748,6 +750,7 @@ struct tegra_clk_super_mux {
 
 #define TEGRA_DIVIDER_2 BIT(0)
 #define TEGRA210_CPU_CLK BIT(1)
+#define TEGRA20_SUPER_CLK BIT(2)
 
 extern const struct clk_ops tegra_clk_super_ops;
 struct clk *tegra_clk_register_super_mux(const char *name,
@@ -758,6 +761,10 @@ struct clk *tegra_clk_register_super_clk(const char *name,
 		const char * const *parent_names, u8 num_parents,
 		unsigned long flags, void __iomem *reg, u8 clk_super_flags,
 		spinlock_t *lock);
+struct clk *tegra_clk_register_super_cclk(const char *name,
+		const char * const *parent_names, u8 num_parents,
+		unsigned long flags, void __iomem *reg, u8 clk_super_flags,
+		spinlock_t *lock);
 
 /**
  * struct tegra_sdmmc_mux - switch divider with Low Jitter inputs for SDMMC
-- 
2.23.0

[PATCH v4 02/10] clk: tegra: pll: Add pre/post rate-change hooks

[Dmitry Osipenko]

There is a need to temporarily re-parent CCLK away from PLLX if PLLX's
rate is about to change. The newly introduced PLL pre/post rate-change
hooks allow to handle such case.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-pll.c | 12 +++++++++++-
 drivers/clk/tegra/clk.h     |  6 ++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
index 531c2b3d814e..0b212cf2e794 100644
--- a/drivers/clk/tegra/clk-pll.c
+++ b/drivers/clk/tegra/clk-pll.c
@@ -744,13 +744,19 @@ static int _program_pll(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
 
 	state = clk_pll_is_enabled(hw);
 
+	if (state && pll->params->pre_rate_change) {
+		ret = pll->params->pre_rate_change();
+		if (WARN_ON(ret))
+			return ret;
+	}
+
 	_get_pll_mnp(pll, &old_cfg);
 
 	if (state && pll->params->defaults_set && pll->params->dyn_ramp &&
 			(cfg->m == old_cfg.m) && (cfg->p == old_cfg.p)) {
 		ret = pll->params->dyn_ramp(pll, cfg);
 		if (!ret)
-			return 0;
+			goto done;
 	}
 
 	if (state) {
@@ -772,6 +778,10 @@ static int _program_pll(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
 		pll_clk_start_ss(pll);
 	}
 
+done:
+	if (state && pll->params->post_rate_change)
+		pll->params->post_rate_change();
+
 	return ret;
 }
 
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index ee35a847df08..fa18bef914af 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -266,6 +266,10 @@ struct tegra_clk_pll;
  *				disabled.
  * @dyn_ramp:			Callback which can be used to define a custom
  *				dynamic ramp function for a given PLL.
+ * @pre_rate_change:		Callback which is invoked just before changing
+ *				PLL's rate.
+ * @post_rate_change:		Callback which is invoked right after changing
+ *				PLL's rate.
  *
  * Flags:
  * TEGRA_PLL_USE_LOCK - This flag indicated to use lock bits for
@@ -342,6 +346,8 @@ struct tegra_clk_pll_params {
 	void	(*set_defaults)(struct tegra_clk_pll *pll);
 	int	(*dyn_ramp)(struct tegra_clk_pll *pll,
 			struct tegra_clk_pll_freq_table *cfg);
+	int	(*pre_rate_change)(void);
+	void	(*post_rate_change)(void);
 };
 
 #define TEGRA_PLL_USE_LOCK BIT(0)
-- 
2.23.0

[PATCH v4 03/10] clk: tegra: cclk: Add helpers for handling PLLX rate changes

[Dmitry Osipenko]

CCLK should be re-parented away from PLLX if PLLX's rate is changing.
The PLLP parent is a common safe CPU parent for all Tegra SoCs, thus
CCLK will be re-parented to PLLP before PLLX rate-change begins and then
switched back to PLLX after the rate-change completion. This patch adds
helper functions which perform CCLK re-parenting, these helpers will be
utilized by further patches.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-tegra-super-cclk.c | 34 ++++++++++++++++++++++++
 drivers/clk/tegra/clk.h                  |  2 ++
 2 files changed, 36 insertions(+)

diff --git a/drivers/clk/tegra/clk-tegra-super-cclk.c b/drivers/clk/tegra/clk-tegra-super-cclk.c
index 7bcb9e8d0860..a03119c30456 100644
--- a/drivers/clk/tegra/clk-tegra-super-cclk.c
+++ b/drivers/clk/tegra/clk-tegra-super-cclk.c
@@ -25,6 +25,9 @@
 
 #define SUPER_CDIV_ENB		BIT(31)
 
+static struct tegra_clk_super_mux *cclk_super;
+static bool cclk_on_pllx;
+
 static u8 cclk_super_get_parent(struct clk_hw *hw)
 {
 	return tegra_clk_super_ops.get_parent(hw);
@@ -115,6 +118,9 @@ struct clk *tegra_clk_register_super_cclk(const char *name,
 	struct clk_init_data init;
 	u32 val;
 
+	if (WARN_ON(cclk_super))
+		return ERR_PTR(-EBUSY);
+
 	super = kzalloc(sizeof(*super), GFP_KERNEL);
 	if (!super)
 		return ERR_PTR(-ENOMEM);
@@ -173,6 +179,34 @@ struct clk *tegra_clk_register_super_cclk(const char *name,
 	clk = clk_register(NULL, &super->hw);
 	if (IS_ERR(clk))
 		kfree(super);
+	else
+		cclk_super = super;
 
 	return clk;
 }
+
+int tegra_cclk_pre_pllx_rate_change(void)
+{
+	if (IS_ERR_OR_NULL(cclk_super))
+		return -EINVAL;
+
+	if (cclk_super_get_parent(&cclk_super->hw) == PLLX_INDEX)
+		cclk_on_pllx = true;
+	else
+		cclk_on_pllx = false;
+
+	/*
+	 * CPU needs to be temporarily re-parented away from PLLX if PLLX
+	 * changes its rate. PLLP is a safe parent for CPU on all Tegra SoCs.
+	 */
+	if (cclk_on_pllx)
+		cclk_super_set_parent(&cclk_super->hw, PLLP_INDEX);
+
+	return 0;
+}
+
+void tegra_cclk_post_pllx_rate_change(void)
+{
+	if (cclk_on_pllx)
+		cclk_super_set_parent(&cclk_super->hw, PLLX_INDEX);
+}
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index fa18bef914af..0afe28f4372b 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -771,6 +771,8 @@ struct clk *tegra_clk_register_super_cclk(const char *name,
 		const char * const *parent_names, u8 num_parents,
 		unsigned long flags, void __iomem *reg, u8 clk_super_flags,
 		spinlock_t *lock);
+int tegra_cclk_pre_pllx_rate_change(void);
+void tegra_cclk_post_pllx_rate_change(void);
 
 /**
  * struct tegra_sdmmc_mux - switch divider with Low Jitter inputs for SDMMC
-- 
2.23.0

[PATCH v4 04/10] clk: tegra20: Use custom CCLK implementation

[Dmitry Osipenko]

We're going to use the generic cpufreq-dt driver on Tegra20 and thus CCLK
intermediate re-parenting will be performed by the clock driver. There is
now special CCLK implementation that supports all CCLK quirks, this patch
makes Tegra20 SoCs to use that implementation.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-tegra20.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c
index 4d8222f5c638..eb821666ca61 100644
--- a/drivers/clk/tegra/clk-tegra20.c
+++ b/drivers/clk/tegra/clk-tegra20.c
@@ -391,6 +391,8 @@ static struct tegra_clk_pll_params pll_x_params = {
 	.lock_delay = 300,
 	.freq_table = pll_x_freq_table,
 	.flags = TEGRA_PLL_HAS_CPCON | TEGRA_PLL_HAS_LOCK_ENABLE,
+	.pre_rate_change = tegra_cclk_pre_pllx_rate_change,
+	.post_rate_change = tegra_cclk_post_pllx_rate_change,
 };
 
 static struct tegra_clk_pll_params pll_e_params = {
@@ -704,9 +706,10 @@ static void tegra20_super_clk_init(void)
 	struct clk *clk;
 
 	/* CCLK */
-	clk = tegra_clk_register_super_mux("cclk", cclk_parents,
+	clk = tegra_clk_register_super_cclk("cclk", cclk_parents,
 			      ARRAY_SIZE(cclk_parents), CLK_SET_RATE_PARENT,
-			      clk_base + CCLK_BURST_POLICY, 0, 4, 0, 0, NULL);
+			      clk_base + CCLK_BURST_POLICY, TEGRA20_SUPER_CLK,
+			      NULL);
 	clks[TEGRA20_CLK_CCLK] = clk;
 
 	/* SCLK */
-- 
2.23.0

[PATCH v4 05/10] clk: tegra30: Use custom CCLK implementation

[Dmitry Osipenko]

We're going to use the generic cpufreq-dt driver on Tegra30 and thus CCLK
intermediate re-parenting will be performed by the clock driver. There is
now special CCLK implementation that supports all CCLK quirks, this patch
makes Tegra30 SoCs to use that implementation.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-tegra30.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c
index c8bc18e4d7e5..0fe03d69fe1a 100644
--- a/drivers/clk/tegra/clk-tegra30.c
+++ b/drivers/clk/tegra/clk-tegra30.c
@@ -499,6 +499,8 @@ static struct tegra_clk_pll_params pll_x_params __ro_after_init = {
 	.freq_table = pll_x_freq_table,
 	.flags = TEGRA_PLL_HAS_CPCON | TEGRA_PLL_SET_DCCON |
 		 TEGRA_PLL_USE_LOCK | TEGRA_PLL_HAS_LOCK_ENABLE,
+	.pre_rate_change = tegra_cclk_pre_pllx_rate_change,
+	.post_rate_change = tegra_cclk_post_pllx_rate_change,
 };
 
 static struct tegra_clk_pll_params pll_e_params __ro_after_init = {
@@ -932,11 +934,11 @@ static void __init tegra30_super_clk_init(void)
 	clk_register_clkdev(clk, "pll_p_out4_cclkg", NULL);
 
 	/* CCLKG */
-	clk = tegra_clk_register_super_mux("cclk_g", cclk_g_parents,
+	clk = tegra_clk_register_super_cclk("cclk_g", cclk_g_parents,
 				  ARRAY_SIZE(cclk_g_parents),
 				  CLK_SET_RATE_PARENT,
 				  clk_base + CCLKG_BURST_POLICY,
-				  0, 4, 0, 0, NULL);
+				  0, NULL);
 	clks[TEGRA30_CLK_CCLK_G] = clk;
 
 	/*
-- 
2.23.0

[PATCH v4 06/10] dt-bindings: cpufreq: Add binding for NVIDIA Tegra20/30

[Dmitry Osipenko]

Add device-tree binding that describes CPU frequency-scaling hardware
found on NVIDIA Tegra20/30 SoCs.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../cpufreq/nvidia,tegra20-cpufreq.txt        | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt

diff --git a/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt b/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
new file mode 100644
index 000000000000..daeca6ae6b76
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
@@ -0,0 +1,56 @@
+Binding for NVIDIA Tegra20 CPUFreq
+==================================
+
+Required properties:
+- clocks: Must contain an entry for the CPU clock.
+  See ../clocks/clock-bindings.txt for details.
+- operating-points-v2: See ../bindings/opp/opp.txt for details.
+- #cooling-cells: Should be 2. See ../thermal/thermal.txt for details.
+
+For each opp entry in 'operating-points-v2' table:
+- opp-supported-hw: Two bitfields indicating:
+	On Tegra20:
+	1. CPU process ID mask
+	2. SoC speedo ID mask
+
+	On Tegra30:
+	1. CPU process ID mask
+	2. CPU speedo ID mask
+
+	A bitwise AND is performed against these values and if any bit
+	matches, the OPP gets enabled.
+
+- opp-microvolt: CPU voltage triplet.
+
+Optional properties:
+- cpu-supply: Phandle to the CPU power supply.
+
+Example:
+	regulators {
+		cpu_reg: regulator0 {
+			regulator-name = "vdd_cpu";
+		};
+	};
+
+	cpu0_opp_table: opp_table0 {
+		compatible = "operating-points-v2";
+
+		opp@456000000 {
+			clock-latency-ns = <125000>;
+			opp-microvolt = <825000 825000 1125000>;
+			opp-supported-hw = <0x03 0x0001>;
+			opp-hz = /bits/ 64 <456000000>;
+		};
+
+		...
+	};
+
+	cpus {
+		cpu@0 {
+			compatible = "arm,cortex-a9";
+			clocks = <&tegra_car TEGRA20_CLK_CCLK>;
+			operating-points-v2 = <&cpu0_opp_table>;
+			cpu-supply = <&cpu_reg>;
+			#cooling-cells = <2>;
+		};
+	};
-- 
2.23.0

[PATCH v4 07/10] cpufreq: tegra20: Use generic cpufreq-dt driver (Tegra30 supported now)

[Dmitry Osipenko]

Re-parenting to intermediate clock is supported now by the clock driver
and thus there is no need in a customized CPUFreq driver, all that code
is common for both Tegra20 and Tegra30. The available CPU freqs are now
specified in device-tree in a form of OPPs, all users should update their
device-trees.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/cpufreq/Kconfig.arm          |   6 +-
 drivers/cpufreq/cpufreq-dt-platdev.c |   2 +
 drivers/cpufreq/tegra20-cpufreq.c    | 217 +++++++--------------------
 3 files changed, 61 insertions(+), 164 deletions(-)

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 3858d86cf409..92a6a5089979 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -295,11 +295,11 @@ config ARM_TANGO_CPUFREQ
 	default y
 
 config ARM_TEGRA20_CPUFREQ
-	tristate "Tegra20 CPUFreq support"
-	depends on ARCH_TEGRA
+	tristate "Tegra20/30 CPUFreq support"
+	depends on ARCH_TEGRA && CPUFREQ_DT
 	default y
 	help
-	  This adds the CPUFreq driver support for Tegra20 SOCs.
+	  This adds the CPUFreq driver support for Tegra20/30 SOCs.
 
 config ARM_TEGRA124_CPUFREQ
 	bool "Tegra124 CPUFreq support"
diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
index f1d170dcf4d3..aba591d57c67 100644
--- a/drivers/cpufreq/cpufreq-dt-platdev.c
+++ b/drivers/cpufreq/cpufreq-dt-platdev.c
@@ -121,6 +121,8 @@ static const struct of_device_id blacklist[] __initconst = {
 	{ .compatible = "mediatek,mt8176", },
 	{ .compatible = "mediatek,mt8183", },
 
+	{ .compatible = "nvidia,tegra20", },
+	{ .compatible = "nvidia,tegra30", },
 	{ .compatible = "nvidia,tegra124", },
 	{ .compatible = "nvidia,tegra210", },
 
diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
index f84ecd22f488..8c893043953e 100644
--- a/drivers/cpufreq/tegra20-cpufreq.c
+++ b/drivers/cpufreq/tegra20-cpufreq.c
@@ -7,201 +7,96 @@
  *	Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
  */
 
-#include <linux/clk.h>
-#include <linux/cpufreq.h>
+#include <linux/bits.h>
+#include <linux/cpu.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/pm_opp.h>
 #include <linux/types.h>
 
-static struct cpufreq_frequency_table freq_table[] = {
-	{ .frequency = 216000 },
-	{ .frequency = 312000 },
-	{ .frequency = 456000 },
-	{ .frequency = 608000 },
-	{ .frequency = 760000 },
-	{ .frequency = 816000 },
-	{ .frequency = 912000 },
-	{ .frequency = 1000000 },
-	{ .frequency = CPUFREQ_TABLE_END },
-};
-
-struct tegra20_cpufreq {
-	struct device *dev;
-	struct cpufreq_driver driver;
-	struct clk *cpu_clk;
-	struct clk *pll_x_clk;
-	struct clk *pll_p_clk;
-	bool pll_x_prepared;
-};
+#include <soc/tegra/common.h>
+#include <soc/tegra/fuse.h>
 
-static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy,
-					   unsigned int index)
+static bool cpu0_node_has_opp_v2_prop(void)
 {
-	struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
-	unsigned int ifreq = clk_get_rate(cpufreq->pll_p_clk) / 1000;
-
-	/*
-	 * Don't switch to intermediate freq if:
-	 * - we are already at it, i.e. policy->cur == ifreq
-	 * - index corresponds to ifreq
-	 */
-	if (freq_table[index].frequency == ifreq || policy->cur == ifreq)
-		return 0;
-
-	return ifreq;
-}
+	struct device_node *np = of_cpu_device_node_get(0);
+	bool ret = false;
 
-static int tegra_target_intermediate(struct cpufreq_policy *policy,
-				     unsigned int index)
-{
-	struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
-	int ret;
-
-	/*
-	 * Take an extra reference to the main pll so it doesn't turn
-	 * off when we move the cpu off of it as enabling it again while we
-	 * switch to it from tegra_target() would take additional time.
-	 *
-	 * When target-freq is equal to intermediate freq we don't need to
-	 * switch to an intermediate freq and so this routine isn't called.
-	 * Also, we wouldn't be using pll_x anymore and must not take extra
-	 * reference to it, as it can be disabled now to save some power.
-	 */
-	clk_prepare_enable(cpufreq->pll_x_clk);
-
-	ret = clk_set_parent(cpufreq->cpu_clk, cpufreq->pll_p_clk);
-	if (ret)
-		clk_disable_unprepare(cpufreq->pll_x_clk);
-	else
-		cpufreq->pll_x_prepared = true;
+	if (of_get_property(np, "operating-points-v2", NULL))
+		ret = true;
 
+	of_node_put(np);
 	return ret;
 }
 
-static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
-{
-	struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
-	unsigned long rate = freq_table[index].frequency;
-	unsigned int ifreq = clk_get_rate(cpufreq->pll_p_clk) / 1000;
-	int ret;
-
-	/*
-	 * target freq == pll_p, don't need to take extra reference to pll_x_clk
-	 * as it isn't used anymore.
-	 */
-	if (rate == ifreq)
-		return clk_set_parent(cpufreq->cpu_clk, cpufreq->pll_p_clk);
-
-	ret = clk_set_rate(cpufreq->pll_x_clk, rate * 1000);
-	/* Restore to earlier frequency on error, i.e. pll_x */
-	if (ret)
-		dev_err(cpufreq->dev, "Failed to change pll_x to %lu\n", rate);
-
-	ret = clk_set_parent(cpufreq->cpu_clk, cpufreq->pll_x_clk);
-	/* This shouldn't fail while changing or restoring */
-	WARN_ON(ret);
-
-	/*
-	 * Drop count to pll_x clock only if we switched to intermediate freq
-	 * earlier while transitioning to a target frequency.
-	 */
-	if (cpufreq->pll_x_prepared) {
-		clk_disable_unprepare(cpufreq->pll_x_clk);
-		cpufreq->pll_x_prepared = false;
-	}
-
-	return ret;
-}
-
-static int tegra_cpu_init(struct cpufreq_policy *policy)
-{
-	struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
-
-	clk_prepare_enable(cpufreq->cpu_clk);
-
-	/* FIXME: what's the actual transition time? */
-	cpufreq_generic_init(policy, freq_table, 300 * 1000);
-	policy->clk = cpufreq->cpu_clk;
-	policy->suspend_freq = freq_table[0].frequency;
-	return 0;
-}
-
-static int tegra_cpu_exit(struct cpufreq_policy *policy)
-{
-	struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
-
-	clk_disable_unprepare(cpufreq->cpu_clk);
-	return 0;
-}
-
 static int tegra20_cpufreq_probe(struct platform_device *pdev)
 {
-	struct tegra20_cpufreq *cpufreq;
+	struct platform_device *cpufreq_dt;
+	struct opp_table *opp_table;
+	struct device *cpu_dev;
+	u32 versions[2];
 	int err;
 
-	cpufreq = devm_kzalloc(&pdev->dev, sizeof(*cpufreq), GFP_KERNEL);
-	if (!cpufreq)
-		return -ENOMEM;
+	if (!cpu0_node_has_opp_v2_prop()) {
+		dev_err(&pdev->dev, "operating points not found\n");
+		dev_err(&pdev->dev, "please update your device tree\n");
+		return -ENODEV;
+	}
+
+	if (of_machine_is_compatible("nvidia,tegra20")) {
+		versions[0] = BIT(tegra_sku_info.cpu_process_id);
+		versions[1] = BIT(tegra_sku_info.soc_speedo_id);
+	} else {
+		versions[0] = BIT(tegra_sku_info.cpu_process_id);
+		versions[1] = BIT(tegra_sku_info.cpu_speedo_id);
+	}
+
+	dev_info(&pdev->dev, "hardware version 0x%x 0x%x\n",
+		 versions[0], versions[1]);
 
-	cpufreq->cpu_clk = clk_get_sys(NULL, "cclk");
-	if (IS_ERR(cpufreq->cpu_clk))
-		return PTR_ERR(cpufreq->cpu_clk);
+	cpu_dev = get_cpu_device(0);
+	if (WARN_ON(!cpu_dev))
+		return -ENODEV;
 
-	cpufreq->pll_x_clk = clk_get_sys(NULL, "pll_x");
-	if (IS_ERR(cpufreq->pll_x_clk)) {
-		err = PTR_ERR(cpufreq->pll_x_clk);
-		goto put_cpu;
+	opp_table = dev_pm_opp_set_supported_hw(cpu_dev, versions, 2);
+	err = PTR_ERR_OR_ZERO(opp_table);
+	if (err) {
+		dev_err(&pdev->dev, "failed to set supported hw: %d\n", err);
+		return err;
 	}
 
-	cpufreq->pll_p_clk = clk_get_sys(NULL, "pll_p");
-	if (IS_ERR(cpufreq->pll_p_clk)) {
-		err = PTR_ERR(cpufreq->pll_p_clk);
-		goto put_pll_x;
+	cpufreq_dt = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
+	err = PTR_ERR_OR_ZERO(cpufreq_dt);
+	if (err) {
+		dev_err(&pdev->dev,
+			"failed to create cpufreq-dt device: %d\n", err);
+		goto err_put_supported_hw;
 	}
 
-	cpufreq->dev = &pdev->dev;
-	cpufreq->driver.get = cpufreq_generic_get;
-	cpufreq->driver.attr = cpufreq_generic_attr;
-	cpufreq->driver.init = tegra_cpu_init;
-	cpufreq->driver.exit = tegra_cpu_exit;
-	cpufreq->driver.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK;
-	cpufreq->driver.verify = cpufreq_generic_frequency_table_verify;
-	cpufreq->driver.suspend = cpufreq_generic_suspend;
-	cpufreq->driver.driver_data = cpufreq;
-	cpufreq->driver.target_index = tegra_target;
-	cpufreq->driver.get_intermediate = tegra_get_intermediate;
-	cpufreq->driver.target_intermediate = tegra_target_intermediate;
-	snprintf(cpufreq->driver.name, CPUFREQ_NAME_LEN, "tegra");
-
-	err = cpufreq_register_driver(&cpufreq->driver);
-	if (err)
-		goto put_pll_p;
-
-	platform_set_drvdata(pdev, cpufreq);
+	platform_set_drvdata(pdev, cpufreq_dt);
 
 	return 0;
 
-put_pll_p:
-	clk_put(cpufreq->pll_p_clk);
-put_pll_x:
-	clk_put(cpufreq->pll_x_clk);
-put_cpu:
-	clk_put(cpufreq->cpu_clk);
+err_put_supported_hw:
+	dev_pm_opp_put_supported_hw(opp_table);
 
 	return err;
 }
 
 static int tegra20_cpufreq_remove(struct platform_device *pdev)
 {
-	struct tegra20_cpufreq *cpufreq = platform_get_drvdata(pdev);
+	struct platform_device *cpufreq_dt;
+	struct opp_table *opp_table;
 
-	cpufreq_unregister_driver(&cpufreq->driver);
+	cpufreq_dt = platform_get_drvdata(pdev);
+	platform_device_unregister(cpufreq_dt);
 
-	clk_put(cpufreq->pll_p_clk);
-	clk_put(cpufreq->pll_x_clk);
-	clk_put(cpufreq->cpu_clk);
+	opp_table = dev_pm_opp_get_opp_table(get_cpu_device(0));
+	dev_pm_opp_put_supported_hw(opp_table);
+	dev_pm_opp_put_opp_table(opp_table);
 
 	return 0;
 }
-- 
2.23.0

[PATCH v4 08/10] ARM: tegra: Create tegra20-cpufreq platform device on Tegra30

[Dmitry Osipenko]

The tegra20-cpufreq now instantiates cpufreq-dt and Tegra30 is fully
supported by that driver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/mach-tegra/tegra.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
index e512e606eabd..1e3b85923ca3 100644
--- a/arch/arm/mach-tegra/tegra.c
+++ b/arch/arm/mach-tegra/tegra.c
@@ -95,6 +95,10 @@ static void __init tegra_dt_init_late(void)
 	if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) &&
 	    of_machine_is_compatible("nvidia,tegra20"))
 		platform_device_register_simple("tegra20-cpufreq", -1, NULL, 0);
+
+	if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) &&
+	    of_machine_is_compatible("nvidia,tegra30"))
+		platform_device_register_simple("tegra20-cpufreq", -1, NULL, 0);
 }
 
 static const char * const tegra_dt_board_compat[] = {
-- 
2.23.0

[PATCH v4 09/10] ARM: dts: tegra30: beaver: Set up voltage regulators for DVFS

[Dmitry Osipenko]

Set min/max voltage and couple CPU/CORE regulators.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra30-beaver.dts | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/arm/boot/dts/tegra30-beaver.dts b/arch/arm/boot/dts/tegra30-beaver.dts
index a3b0f3555cd2..6ebb3105af9e 100644
--- a/arch/arm/boot/dts/tegra30-beaver.dts
+++ b/arch/arm/boot/dts/tegra30-beaver.dts
@@ -1806,9 +1806,14 @@
 
 				vddctrl_reg: vddctrl {
 					regulator-name = "vdd_cpu,vdd_sys";
-					regulator-min-microvolt = <1000000>;
-					regulator-max-microvolt = <1000000>;
+					regulator-min-microvolt = <800000>;
+					regulator-max-microvolt = <1250000>;
+					regulator-coupled-with = <&core_vdd_reg>;
+					regulator-coupled-max-spread = <300000>;
+					regulator-max-step-microvolt = <100000>;
 					regulator-always-on;
+
+					nvidia,tegra-cpu-regulator;
 				};
 
 				vio_reg: vio {
@@ -1868,17 +1873,22 @@
 			};
 		};
 
-		tps62361@60 {
+		core_vdd_reg: tps62361@60 {
 			compatible = "ti,tps62361";
 			reg = <0x60>;
 
 			regulator-name = "tps62361-vout";
 			regulator-min-microvolt = <500000>;
 			regulator-max-microvolt = <1500000>;
+			regulator-coupled-with = <&vddctrl_reg>;
+			regulator-coupled-max-spread = <300000>;
+			regulator-max-step-microvolt = <100000>;
 			regulator-boot-on;
 			regulator-always-on;
 			ti,vsel0-state-high;
 			ti,vsel1-state-high;
+
+			nvidia,tegra-core-regulator;
 		};
 	};
 
-- 
2.23.0

[PATCH v4 10/10] ARM: dts: tegra30: beaver: Add CPU Operating Performance Points

[Dmitry Osipenko]

Utilize common Tegra30 CPU OPP table. CPU DVFS is available now on beaver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra30-beaver.dts | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm/boot/dts/tegra30-beaver.dts b/arch/arm/boot/dts/tegra30-beaver.dts
index 6ebb3105af9e..86556622be25 100644
--- a/arch/arm/boot/dts/tegra30-beaver.dts
+++ b/arch/arm/boot/dts/tegra30-beaver.dts
@@ -2,6 +2,8 @@
 /dts-v1/;
 
 #include "tegra30.dtsi"
+#include "tegra30-cpu-opp.dtsi"
+#include "tegra30-cpu-opp-microvolt.dtsi"
 
 / {
 	model = "NVIDIA Tegra30 Beaver evaluation board";
@@ -2124,4 +2126,26 @@
 			 <&tegra_car TEGRA30_CLK_EXTERN1>;
 		clock-names = "pll_a", "pll_a_out0", "mclk";
 	};
+
+	cpus {
+		cpu0: cpu@0 {
+			cpu-supply = <&vddctrl_reg>;
+			operating-points-v2 = <&cpu0_opp_table>;
+		};
+
+		cpu@1 {
+			cpu-supply = <&vddctrl_reg>;
+			operating-points-v2 = <&cpu0_opp_table>;
+		};
+
+		cpu@2 {
+			cpu-supply = <&vddctrl_reg>;
+			operating-points-v2 = <&cpu0_opp_table>;
+		};
+
+		cpu@3 {
+			cpu-supply = <&vddctrl_reg>;
+			operating-points-v2 = <&cpu0_opp_table>;
+		};
+	};
 };
-- 
2.23.0