[PATCH v5 00/36] Introduce memory interconnect for NVIDIA Tegra SoCs

[PATCH v5 00/36] Introduce memory interconnect for NVIDIA Tegra SoCs

[Dmitry Osipenko]

Hello,

This series brings initial support for memory interconnect to Tegra20 and
Tegra30 SoCs.

For the starter only display controllers are getting interconnect API
support, others could be supported later on. The display controllers
have the biggest demand for interconnect API right now because dynamic
memory frequency scaling can't be done safely without taking into account
bandwidth requirement from the displays.

Changelog:

v5: - The devfreq drivers now won't probe if memory timings aren't specified
      in a device-tree, like was suggested by Chanwoo Choi in a review comment
      to v4. Initially I wanted to always probe the driver even with a single
      fixed memory freq, but after a closer look turned out it can't be done
      easily for Tegra20 driver.

    - The "interconnect: Relax requirement in of_icc_get_from_provider()"
      patch was already applied, hence one less patch in comparison to v4.

    - Renamed display interconnect paths in accordance to the names that
      were used by Thierry Reding in one of his recent patches that supposed
      to update the Host1x's DT binding.

    - Added acks from Chanwoo Choi.

    - Added clarifying comment to tegra_mc_icc_set() about why it's a dummy
      function, this is done in a response to the review comment made by
      Georgi Djakov to v4.

v4: - All drivers that use interconnect API now select it in the Kconfig in
      order to properly express the build dependency.

    - The IS_ENABLED(CONFIG_INTERCONNECT) is dropped now from all patches.

    - Added MODULE_AUTHOR() to the modularized drivers, for completeness.

    - Added missed TEGRA_MC Kconfig dependency for the Tegra20 EMC driver.

    - Added more acks from Rob Herring that I accidentally missed to add in v3.

v3: - Added acks from Rob Herring that were given to some of the v2 patches.

    - Specified name of the TRM documentation chapter in the patch
      "dt-bindings: host1x: Document new interconnect properties", which was
      suggested by Rob Herring in the review comment to v2.

    - Added patches that allow EMC drivers to be compiled as a loadable kernel
      modules. This came up during of the v2 review when Georgi Djakov pointed
      out that interconnect-core could be compiled as a kernel module. Please
      note that the Tegra124 EMC driver is compile-tested only, I don't have
      Tegra124 HW.

    - In the review comment to [1] Stephen Boyd suggested that it will be
      better not to make changes to clk API, which was needed in order to
      avoid clashing of the interconnect driver with the devfreq in regards
      to memory clk-rate rounding.

      [1] https://patchwork.ozlabs.org/project/linux-tegra/patch/20200330231617.17079-3-digetx@gmail.com/

      Stephen Boyd suggested that instead we should provide OPP table via DT.
      I tried to investigate whether this could be done and turned out
      it's a bit complicated. Technically it should be doable, but:

        1. For now we don't fully support voltage scaling of the CORE regulator
           and so OPP table in the DT isn't really needed today. We can
           generate table from the memory timings, which is what Tegra devfreq
           drivers already do.

        2. The OPP table should be defined in the DT for the Memory Controller
           node and then its usage somehow should be shared by both interconnect
           and devfreq drivers. It's not obvious what's the best way to do it.

      So, it will be much better to postpone the DT OPP table addition
      until these questions are resolved. We can infer OPPs from the
      memory timings and we could get the memory rates from the memory
      driver directly, avoiding the problems induced by the clk API usage.
      This idea is implemented in v3, see these patches:

        PM / devfreq: tegra20: Use MC timings for building OPP table
        PM / devfreq: tegra30: Use MC timings for building OPP table

v2: - Instead of a single dma-mem interconnect path, the paths are now
      defined per memory client.

    - The EMC provider now uses #interconnect-cells=<0>.

    - Dropped Tegra124 because there is no enough information about how to
      properly calculate required EMC clock rate for it and I don't have
      hardware for testing. Somebody else will have to work on it.

    - Moved interconnect providers code into drivers/memory/tegra/*.

    - Added "Create tegra20-devfreq device" patch because interconnect
      is not very usable without the devfreq memory auto-scaling since
      memory freq will be fixed to the display's requirement.

Dmitry Osipenko (36):
  clk: Export clk_hw_reparent()
  clk: tegra: Remove Memory Controller lock
  clk: tegra: Export Tegra20 EMC kernel symbols
  memory: tegra20-emc: Make driver modular
  memory: tegra30-emc: Make driver modular
  memory: tegra124-emc: Make driver modular
  memory: tegra124-emc: Use devm_platform_ioremap_resource
  soc/tegra: fuse: Export tegra_read_ram_code()
  memory: tegra20-emc: Initialize MC timings
  PM / devfreq: tegra20: Silence deferred probe error
  PM / devfreq: tegra30: Silence deferred probe error
  PM / devfreq: tegra20: Use MC timings for building OPP table
  PM / devfreq: tegra30: Use MC timings for building OPP table
  PM / devfreq: tegra20: Add error messages to tegra_devfreq_target()
  PM / devfreq: tegra30: Add error messages to tegra_devfreq_target()
  PM / devfreq: tegra20: Adjust clocks conversion ratio and polling
    interval
  PM / devfreq: tegra20: Relax Kconfig dependency
  dt-bindings: memory: tegra20: mc: Document new interconnect property
  dt-bindings: memory: tegra20: emc: Document new interconnect property
  dt-bindings: memory: tegra30: mc: Document new interconnect property
  dt-bindings: memory: tegra30: emc: Document new interconnect property
  dt-bindings: host1x: Document new interconnect properties
  dt-bindings: memory: tegra20: Add memory client IDs
  dt-bindings: memory: tegra30: Add memory client IDs
  ARM: tegra: Add interconnect properties to Tegra20 device-tree
  ARM: tegra: Add interconnect properties to Tegra30 device-tree
  memory: tegra-mc: Register as interconnect provider
  memory: tegra20-emc: Use devm_platform_ioremap_resource
  memory: tegra20-emc: Continue probing if timings are missing in
    device-tree
  memory: tegra20-emc: Register as interconnect provider
  memory: tegra20-emc: Create tegra20-devfreq device
  memory: tegra30-emc: Continue probing if timings are missing in
    device-tree
  memory: tegra30-emc: Register as interconnect provider
  drm/tegra: dc: Support memory bandwidth management
  drm/tegra: dc: Tune up high priority request controls for Tegra20
  drm/tegra: dc: Extend debug stats with total number of events

 .../display/tegra/nvidia,tegra20-host1x.txt   |  68 +++++
 .../memory-controllers/nvidia,tegra20-emc.txt |   2 +
 .../memory-controllers/nvidia,tegra20-mc.txt  |   3 +
 .../nvidia,tegra30-emc.yaml                   |   6 +
 .../memory-controllers/nvidia,tegra30-mc.yaml |   5 +
 arch/arm/boot/dts/tegra20.dtsi                |  22 +-
 arch/arm/boot/dts/tegra30.dtsi                |  23 +-
 drivers/clk/clk.c                             |   1 +
 drivers/clk/tegra/clk-divider.c               |   4 +-
 drivers/clk/tegra/clk-tegra114.c              |   6 +-
 drivers/clk/tegra/clk-tegra124-emc.c          |  63 ++--
 drivers/clk/tegra/clk-tegra124.c              |   8 +-
 drivers/clk/tegra/clk-tegra20-emc.c           |   3 +
 drivers/clk/tegra/clk-tegra20.c               |   3 +-
 drivers/clk/tegra/clk-tegra30.c               |   3 +-
 drivers/clk/tegra/clk.h                       |  14 +-
 drivers/devfreq/Kconfig                       |   2 +-
 drivers/devfreq/tegra20-devfreq.c             |  50 +--
 drivers/devfreq/tegra30-devfreq.c             | 110 +++++--
 drivers/gpu/drm/tegra/Kconfig                 |   1 +
 drivers/gpu/drm/tegra/dc.c                    | 289 +++++++++++++++++-
 drivers/gpu/drm/tegra/dc.h                    |  13 +
 drivers/gpu/drm/tegra/drm.c                   |  19 ++
 drivers/gpu/drm/tegra/plane.c                 |   1 +
 drivers/gpu/drm/tegra/plane.h                 |   4 +-
 drivers/memory/tegra/Kconfig                  |   9 +-
 drivers/memory/tegra/mc.c                     | 121 ++++++++
 drivers/memory/tegra/mc.h                     |   8 +
 drivers/memory/tegra/tegra124-emc.c           |  36 ++-
 drivers/memory/tegra/tegra20-emc.c            | 222 ++++++++++++--
 drivers/memory/tegra/tegra30-emc.c            | 156 ++++++++--
 drivers/soc/tegra/fuse/tegra-apbmisc.c        |   2 +
 include/dt-bindings/memory/tegra20-mc.h       |  53 ++++
 include/dt-bindings/memory/tegra30-mc.h       |  67 ++++
 include/linux/clk/tegra.h                     |  11 +
 include/soc/tegra/emc.h                       |  16 -
 include/soc/tegra/mc.h                        |   3 +
 37 files changed, 1228 insertions(+), 199 deletions(-)
 delete mode 100644 include/soc/tegra/emc.h

-- 
2.27.0

[PATCH v5 01/36] clk: Export clk_hw_reparent()

[Dmitry Osipenko]

We're going to turn Tegra124 Memory Controller driver into a loadable
kernel module. The driver uses clk_hw_reparent(), which isn't an exported
kernel symbol. Let's export that function in order to allow modularization
of the Tegra driver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/clk.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 0a9261a099bd..2cbaede80fe5 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2448,6 +2448,7 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
 
 	clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
 }
+EXPORT_SYMBOL_GPL(clk_hw_reparent);
 
 /**
  * clk_has_parent - check if a clock is a possible parent for another
-- 
2.27.0

[PATCH v5 02/36] clk: tegra: Remove Memory Controller lock

[Dmitry Osipenko]

The shared Memory Controller lock isn't needed since the time when
Memory Clock was made read-only. The lock could be removed safely now.
Hence let's remove it, this will help a tad to make further patches
cleaner.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-divider.c  | 4 ++--
 drivers/clk/tegra/clk-tegra114.c | 6 ++----
 drivers/clk/tegra/clk-tegra124.c | 7 ++-----
 drivers/clk/tegra/clk-tegra20.c  | 3 +--
 drivers/clk/tegra/clk-tegra30.c  | 3 +--
 drivers/clk/tegra/clk.h          | 2 +-
 6 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/clk/tegra/clk-divider.c b/drivers/clk/tegra/clk-divider.c
index 38daf483ddf1..56adb01638cc 100644
--- a/drivers/clk/tegra/clk-divider.c
+++ b/drivers/clk/tegra/clk-divider.c
@@ -177,10 +177,10 @@ static const struct clk_div_table mc_div_table[] = {
 };
 
 struct clk *tegra_clk_register_mc(const char *name, const char *parent_name,
-				  void __iomem *reg, spinlock_t *lock)
+				  void __iomem *reg)
 {
 	return clk_register_divider_table(NULL, name, parent_name,
 					  CLK_IS_CRITICAL,
 					  reg, 16, 1, CLK_DIVIDER_READ_ONLY,
-					  mc_div_table, lock);
+					  mc_div_table, NULL);
 }
diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c
index bc9e47a4cb60..ca8d9737d301 100644
--- a/drivers/clk/tegra/clk-tegra114.c
+++ b/drivers/clk/tegra/clk-tegra114.c
@@ -134,7 +134,6 @@ static DEFINE_SPINLOCK(pll_d_lock);
 static DEFINE_SPINLOCK(pll_d2_lock);
 static DEFINE_SPINLOCK(pll_u_lock);
 static DEFINE_SPINLOCK(pll_re_lock);
-static DEFINE_SPINLOCK(emc_lock);
 
 static struct div_nmp pllxc_nmp = {
 	.divm_shift = 0,
@@ -1050,10 +1049,9 @@ static __init void tegra114_periph_clk_init(void __iomem *clk_base,
 			       ARRAY_SIZE(mux_pllmcp_clkm),
 			       CLK_SET_RATE_NO_REPARENT,
 			       clk_base + CLK_SOURCE_EMC,
-			       29, 3, 0, &emc_lock);
+			       29, 3, 0, NULL);
 
-	clk = tegra_clk_register_mc("mc", "emc_mux", clk_base + CLK_SOURCE_EMC,
-				    &emc_lock);
+	clk = tegra_clk_register_mc("mc", "emc_mux", clk_base + CLK_SOURCE_EMC);
 	clks[TEGRA114_CLK_MC] = clk;
 
 	clk = tegra_clk_register_periph_gate("mipi-cal", "clk_m", 0, clk_base,
diff --git a/drivers/clk/tegra/clk-tegra124.c b/drivers/clk/tegra/clk-tegra124.c
index e931319dcc9d..0c956e14b9ca 100644
--- a/drivers/clk/tegra/clk-tegra124.c
+++ b/drivers/clk/tegra/clk-tegra124.c
@@ -126,7 +126,6 @@ static DEFINE_SPINLOCK(pll_d_lock);
 static DEFINE_SPINLOCK(pll_e_lock);
 static DEFINE_SPINLOCK(pll_re_lock);
 static DEFINE_SPINLOCK(pll_u_lock);
-static DEFINE_SPINLOCK(emc_lock);
 static DEFINE_SPINLOCK(sor0_lock);
 
 /* possible OSC frequencies in Hz */
@@ -1050,8 +1049,7 @@ static __init void tegra124_periph_clk_init(void __iomem *clk_base,
 					     periph_clk_enb_refcnt);
 	clks[TEGRA124_CLK_DSIB] = clk;
 
-	clk = tegra_clk_register_mc("mc", "emc", clk_base + CLK_SOURCE_EMC,
-				    &emc_lock);
+	clk = tegra_clk_register_mc("mc", "emc", clk_base + CLK_SOURCE_EMC);
 	clks[TEGRA124_CLK_MC] = clk;
 
 	/* cml0 */
@@ -1518,8 +1516,7 @@ static void __init tegra124_132_clock_init_post(struct device_node *np)
 				  tegra124_reset_deassert);
 	tegra_add_of_provider(np, of_clk_src_onecell_get);
 
-	clks[TEGRA124_CLK_EMC] = tegra_clk_register_emc(clk_base, np,
-							&emc_lock);
+	clks[TEGRA124_CLK_EMC] = tegra_clk_register_emc(clk_base, np, NULL);
 
 	tegra_register_devclks(devclks, ARRAY_SIZE(devclks));
 
diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c
index 3efc651b42e3..2f8b6de4198f 100644
--- a/drivers/clk/tegra/clk-tegra20.c
+++ b/drivers/clk/tegra/clk-tegra20.c
@@ -802,8 +802,7 @@ static void __init tegra20_periph_clk_init(void)
 
 	clks[TEGRA20_CLK_EMC] = clk;
 
-	clk = tegra_clk_register_mc("mc", "emc", clk_base + CLK_SOURCE_EMC,
-				    NULL);
+	clk = tegra_clk_register_mc("mc", "emc", clk_base + CLK_SOURCE_EMC);
 	clks[TEGRA20_CLK_MC] = clk;
 
 	/* dsi */
diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c
index 37244a7e68c2..88e8c485f8ae 100644
--- a/drivers/clk/tegra/clk-tegra30.c
+++ b/drivers/clk/tegra/clk-tegra30.c
@@ -1042,8 +1042,7 @@ static void __init tegra30_periph_clk_init(void)
 
 	clks[TEGRA30_CLK_EMC] = clk;
 
-	clk = tegra_clk_register_mc("mc", "emc", clk_base + CLK_SOURCE_EMC,
-				    NULL);
+	clk = tegra_clk_register_mc("mc", "emc", clk_base + CLK_SOURCE_EMC);
 	clks[TEGRA30_CLK_MC] = clk;
 
 	/* cml0 */
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 6b565f6b5f66..5ed8b95d331c 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -136,7 +136,7 @@ struct clk *tegra_clk_register_divider(const char *name,
 		unsigned long flags, u8 clk_divider_flags, u8 shift, u8 width,
 		u8 frac_width, spinlock_t *lock);
 struct clk *tegra_clk_register_mc(const char *name, const char *parent_name,
-				  void __iomem *reg, spinlock_t *lock);
+				  void __iomem *reg);
 
 /*
  * Tegra PLL:
-- 
2.27.0

[PATCH v5 03/36] clk: tegra: Export Tegra20 EMC kernel symbols

[Dmitry Osipenko]

We're going to modularize Tegra EMC drivers and some of the EMC clk driver
symbols need to be exported, let's export them.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-tegra20-emc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/clk/tegra/clk-tegra20-emc.c b/drivers/clk/tegra/clk-tegra20-emc.c
index 03bf0009a33c..dd74b8543bf1 100644
--- a/drivers/clk/tegra/clk-tegra20-emc.c
+++ b/drivers/clk/tegra/clk-tegra20-emc.c
@@ -13,6 +13,7 @@
 #include <linux/clk-provider.h>
 #include <linux/clk/tegra.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
@@ -235,6 +236,7 @@ void tegra20_clk_set_emc_round_callback(tegra20_clk_emc_round_cb *round_cb,
 		emc->cb_arg = cb_arg;
 	}
 }
+EXPORT_SYMBOL_GPL(tegra20_clk_set_emc_round_callback);
 
 bool tegra20_clk_emc_driver_available(struct clk_hw *emc_hw)
 {
@@ -291,3 +293,4 @@ int tegra20_clk_prepare_emc_mc_same_freq(struct clk *emc_clk, bool same)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(tegra20_clk_prepare_emc_mc_same_freq);
-- 
2.27.0

[PATCH v5 04/36] memory: tegra20-emc: Make driver modular

[Dmitry Osipenko]

This patch adds modularization support to the Tegra20 EMC driver. Driver
now can be compiled as a loadable kernel module.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/Kconfig       |  2 +-
 drivers/memory/tegra/tegra20-emc.c | 17 ++++++++++++-----
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index 9f0a96bf9ccc..7e0e1ef87763 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -8,7 +8,7 @@ config TEGRA_MC
 	  NVIDIA Tegra SoCs.
 
 config TEGRA20_EMC
-	bool "NVIDIA Tegra20 External Memory Controller driver"
+	tristate "NVIDIA Tegra20 External Memory Controller driver"
 	default y
 	depends on ARCH_TEGRA_2x_SOC
 	help
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index 83ca46345aba..5aa3a1da2975 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -724,6 +724,13 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, emc);
 	tegra_emc_debugfs_init(emc);
 
+	/*
+	 * Don't allow the kernel module to be unloaded. Unloading adds some
+	 * extra complexity which doesn't really worth the effort in a case of
+	 * this driver.
+	 */
+	try_module_get(THIS_MODULE);
+
 	return 0;
 
 unset_cb:
@@ -736,6 +743,7 @@ static const struct of_device_id tegra_emc_of_match[] = {
 	{ .compatible = "nvidia,tegra20-emc", },
 	{},
 };
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
 
 static struct platform_driver tegra_emc_driver = {
 	.probe = tegra_emc_probe,
@@ -745,9 +753,8 @@ static struct platform_driver tegra_emc_driver = {
 		.suppress_bind_attrs = true,
 	},
 };
+module_platform_driver(tegra_emc_driver);
 
-static int __init tegra_emc_init(void)
-{
-	return platform_driver_register(&tegra_emc_driver);
-}
-subsys_initcall(tegra_emc_init);
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra20 EMC driver");
+MODULE_LICENSE("GPL v2");
-- 
2.27.0

[PATCH v5 05/36] memory: tegra30-emc: Make driver modular

[Dmitry Osipenko]

This patch adds modularization support to the Tegra30 EMC driver. Driver
now can be compiled as a loadable kernel module.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/Kconfig       |  2 +-
 drivers/memory/tegra/mc.c          |  3 +++
 drivers/memory/tegra/tegra30-emc.c | 17 ++++++++++++-----
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index 7e0e1ef87763..bd453de9d446 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -18,7 +18,7 @@ config TEGRA20_EMC
 	  external memory.
 
 config TEGRA30_EMC
-	bool "NVIDIA Tegra30 External Memory Controller driver"
+	tristate "NVIDIA Tegra30 External Memory Controller driver"
 	default y
 	depends on TEGRA_MC && ARCH_TEGRA_3x_SOC
 	help
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index ec8403557ed4..772aa021b5f6 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -6,6 +6,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
+#include <linux/export.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -298,6 +299,7 @@ int tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(tegra_mc_write_emem_configuration);
 
 unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)
 {
@@ -309,6 +311,7 @@ unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)
 
 	return dram_count;
 }
+EXPORT_SYMBOL_GPL(tegra_mc_get_emem_device_count);
 
 static int load_one_timing(struct tegra_mc *mc,
 			   struct tegra_mc_timing *timing,
diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index e448a55cb812..f3082964cfb6 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -1343,6 +1343,13 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, emc);
 	tegra_emc_debugfs_init(emc);
 
+	/*
+	 * Don't allow the kernel module to be unloaded. Unloading adds some
+	 * extra complexity which doesn't really worth the effort in a case of
+	 * this driver.
+	 */
+	try_module_get(THIS_MODULE);
+
 	return 0;
 
 unset_cb:
@@ -1393,6 +1400,7 @@ static const struct of_device_id tegra_emc_of_match[] = {
 	{ .compatible = "nvidia,tegra30-emc", },
 	{},
 };
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
 
 static struct platform_driver tegra_emc_driver = {
 	.probe = tegra_emc_probe,
@@ -1403,9 +1411,8 @@ static struct platform_driver tegra_emc_driver = {
 		.suppress_bind_attrs = true,
 	},
 };
+module_platform_driver(tegra_emc_driver);
 
-static int __init tegra_emc_init(void)
-{
-	return platform_driver_register(&tegra_emc_driver);
-}
-subsys_initcall(tegra_emc_init);
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra30 EMC driver");
+MODULE_LICENSE("GPL v2");
-- 
2.27.0

[PATCH v5 06/36] memory: tegra124-emc: Make driver modular

[Dmitry Osipenko]

This patch adds modularization support to the Tegra124 EMC driver. Driver
now can be compiled as a loadable kernel module.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-tegra124-emc.c | 63 +++++++++++++++++-----------
 drivers/clk/tegra/clk-tegra124.c     |  3 +-
 drivers/clk/tegra/clk.h              | 12 ------
 drivers/memory/tegra/Kconfig         |  2 +-
 drivers/memory/tegra/tegra124-emc.c  | 32 +++++++++-----
 include/linux/clk/tegra.h            | 11 +++++
 include/soc/tegra/emc.h              | 16 -------
 7 files changed, 73 insertions(+), 66 deletions(-)
 delete mode 100644 include/soc/tegra/emc.h

diff --git a/drivers/clk/tegra/clk-tegra124-emc.c b/drivers/clk/tegra/clk-tegra124-emc.c
index 745f9faa98d8..4d8b8f1ba7cd 100644
--- a/drivers/clk/tegra/clk-tegra124-emc.c
+++ b/drivers/clk/tegra/clk-tegra124-emc.c
@@ -11,7 +11,9 @@
 #include <linux/clk-provider.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
+#include <linux/clk/tegra.h>
 #include <linux/delay.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -21,10 +23,10 @@
 #include <linux/string.h>
 
 #include <soc/tegra/fuse.h>
-#include <soc/tegra/emc.h>
 
 #include "clk.h"
 
+#define CLK_BASE 0x60006000
 #define CLK_SOURCE_EMC 0x19c
 
 #define CLK_SOURCE_EMC_EMC_2X_CLK_DIVISOR_SHIFT 0
@@ -79,7 +81,9 @@ struct tegra_clk_emc {
 
 	int num_timings;
 	struct emc_timing *timings;
-	spinlock_t *lock;
+
+	tegra124_emc_prepare_timing_change_cb *prepare_timing_change;
+	tegra124_emc_complete_timing_change_cb *complete_timing_change;
 };
 
 /* Common clock framework callback implementations */
@@ -98,7 +102,7 @@ static unsigned long emc_recalc_rate(struct clk_hw *hw,
 	 */
 	parent_rate = clk_hw_get_rate(clk_hw_get_parent(hw));
 
-	val = readl(tegra->clk_regs + CLK_SOURCE_EMC);
+	val = readl(tegra->clk_regs);
 	div = val & CLK_SOURCE_EMC_EMC_2X_CLK_DIVISOR_MASK;
 
 	return parent_rate / (div + 2) * 2;
@@ -163,7 +167,7 @@ static u8 emc_get_parent(struct clk_hw *hw)
 
 	tegra = container_of(hw, struct tegra_clk_emc, hw);
 
-	val = readl(tegra->clk_regs + CLK_SOURCE_EMC);
+	val = readl(tegra->clk_regs);
 
 	return (val >> CLK_SOURCE_EMC_EMC_2X_CLK_SRC_SHIFT)
 		& CLK_SOURCE_EMC_EMC_2X_CLK_SRC_MASK;
@@ -204,7 +208,6 @@ static int emc_set_timing(struct tegra_clk_emc *tegra,
 	int err;
 	u8 div;
 	u32 car_value;
-	unsigned long flags = 0;
 	struct tegra_emc *emc = emc_ensure_emc_driver(tegra);
 
 	if (!emc)
@@ -241,13 +244,11 @@ static int emc_set_timing(struct tegra_clk_emc *tegra,
 
 	div = timing->parent_rate / (timing->rate / 2) - 2;
 
-	err = tegra_emc_prepare_timing_change(emc, timing->rate);
+	err = tegra->prepare_timing_change(emc, timing->rate);
 	if (err)
 		return err;
 
-	spin_lock_irqsave(tegra->lock, flags);
-
-	car_value = readl(tegra->clk_regs + CLK_SOURCE_EMC);
+	car_value = readl(tegra->clk_regs);
 
 	car_value &= ~CLK_SOURCE_EMC_EMC_2X_CLK_SRC(~0);
 	car_value |= CLK_SOURCE_EMC_EMC_2X_CLK_SRC(timing->parent_index);
@@ -255,11 +256,9 @@ static int emc_set_timing(struct tegra_clk_emc *tegra,
 	car_value &= ~CLK_SOURCE_EMC_EMC_2X_CLK_DIVISOR(~0);
 	car_value |= CLK_SOURCE_EMC_EMC_2X_CLK_DIVISOR(div);
 
-	writel(car_value, tegra->clk_regs + CLK_SOURCE_EMC);
-
-	spin_unlock_irqrestore(tegra->lock, flags);
+	writel(car_value, tegra->clk_regs);
 
-	tegra_emc_complete_timing_change(emc, timing->rate);
+	tegra->complete_timing_change(emc, timing->rate);
 
 	clk_hw_reparent(&tegra->hw, __clk_get_hw(timing->parent));
 	clk_disable_unprepare(tegra->prev_parent);
@@ -473,12 +472,15 @@ static const struct clk_ops tegra_clk_emc_ops = {
 	.get_parent = emc_get_parent,
 };
 
-struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np,
-				   spinlock_t *lock)
+struct clk *
+tegra124_clk_register_emc(struct device_node *emc_np,
+			  tegra124_emc_prepare_timing_change_cb *prep_cb,
+			  tegra124_emc_complete_timing_change_cb *complete_cb)
 {
 	struct tegra_clk_emc *tegra;
 	struct clk_init_data init;
 	struct device_node *node;
+	struct resource res;
 	u32 node_ram_code;
 	struct clk *clk;
 	int err;
@@ -487,12 +489,21 @@ struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np,
 	if (!tegra)
 		return ERR_PTR(-ENOMEM);
 
-	tegra->clk_regs = base;
-	tegra->lock = lock;
+	res.start = CLK_BASE + CLK_SOURCE_EMC;
+	res.end = res.start + 3;
+	res.flags = IORESOURCE_MEM;
 
-	tegra->num_timings = 0;
+	tegra->clk_regs = ioremap(res.start, resource_size(&res));
+	if (!tegra->clk_regs) {
+		pr_err("failed to map CLK_SOURCE_EMC\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	tegra->emc_node = emc_np;
+	tegra->prepare_timing_change = prep_cb;
+	tegra->complete_timing_change = complete_cb;
 
-	for_each_child_of_node(np, node) {
+	for_each_child_of_node(emc_np, node) {
 		err = of_property_read_u32(node, "nvidia,ram-code",
 					   &node_ram_code);
 		if (err)
@@ -512,11 +523,6 @@ struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np,
 	if (tegra->num_timings == 0)
 		pr_warn("%s: no memory timings registered\n", __func__);
 
-	tegra->emc_node = of_parse_phandle(np,
-			"nvidia,external-memory-controller", 0);
-	if (!tegra->emc_node)
-		pr_warn("%s: couldn't find node for EMC driver\n", __func__);
-
 	init.name = "emc";
 	init.ops = &tegra_clk_emc_ops;
 	init.flags = CLK_IS_CRITICAL;
@@ -536,5 +542,12 @@ struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np,
 	/* Allow debugging tools to see the EMC clock */
 	clk_register_clkdev(clk, "emc", "tegra-clk-debug");
 
+	/*
+	 * Don't allow the kernel module to be unloaded, unloading is not
+	 * supported by the EMC driver.
+	 */
+	try_module_get(THIS_MODULE);
+
 	return clk;
-};
+}
+EXPORT_SYMBOL_GPL(tegra124_clk_register_emc);
diff --git a/drivers/clk/tegra/clk-tegra124.c b/drivers/clk/tegra/clk-tegra124.c
index 0c956e14b9ca..228d87367ac6 100644
--- a/drivers/clk/tegra/clk-tegra124.c
+++ b/drivers/clk/tegra/clk-tegra124.c
@@ -928,6 +928,7 @@ static struct tegra_clk tegra124_clks[tegra_clk_max] __initdata = {
 	[tegra_clk_audio4_mux] = { .dt_id = TEGRA124_CLK_AUDIO4_MUX, .present = true },
 	[tegra_clk_spdif_mux] = { .dt_id = TEGRA124_CLK_SPDIF_MUX, .present = true },
 	[tegra_clk_cec] = { .dt_id = TEGRA124_CLK_CEC, .present = true },
+	[tegra_clk_emc] = { .dt_id = TEGRA124_CLK_EMC, .present = false },
 };
 
 static struct tegra_devclk devclks[] __initdata = {
@@ -1516,8 +1517,6 @@ static void __init tegra124_132_clock_init_post(struct device_node *np)
 				  tegra124_reset_deassert);
 	tegra_add_of_provider(np, of_clk_src_onecell_get);
 
-	clks[TEGRA124_CLK_EMC] = tegra_clk_register_emc(clk_base, np, NULL);
-
 	tegra_register_devclks(devclks, ARRAY_SIZE(devclks));
 
 	tegra_cpu_car_ops = &tegra124_cpu_car_ops;
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 5ed8b95d331c..11a8bbe650c5 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -881,18 +881,6 @@ void tegra_super_clk_gen5_init(void __iomem *clk_base,
 			void __iomem *pmc_base, struct tegra_clk *tegra_clks,
 			struct tegra_clk_pll_params *pll_params);
 
-#ifdef CONFIG_TEGRA124_EMC
-struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np,
-				   spinlock_t *lock);
-#else
-static inline struct clk *tegra_clk_register_emc(void __iomem *base,
-						 struct device_node *np,
-						 spinlock_t *lock)
-{
-	return NULL;
-}
-#endif
-
 void tegra114_clock_tune_cpu_trimmers_high(void);
 void tegra114_clock_tune_cpu_trimmers_low(void);
 void tegra114_clock_tune_cpu_trimmers_init(void);
diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index bd453de9d446..c1cad4ce6251 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -28,7 +28,7 @@ config TEGRA30_EMC
 	  external memory.
 
 config TEGRA124_EMC
-	bool "NVIDIA Tegra124 External Memory Controller driver"
+	tristate "NVIDIA Tegra124 External Memory Controller driver"
 	default y
 	depends on TEGRA_MC && ARCH_TEGRA_124_SOC
 	help
diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index a98de2c943d1..93e9835e9761 100644
--- a/drivers/memory/tegra/tegra124-emc.c
+++ b/drivers/memory/tegra/tegra124-emc.c
@@ -9,16 +9,17 @@
 #include <linux/clk-provider.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
+#include <linux/clk/tegra.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/io.h>
+#include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/sort.h>
 #include <linux/string.h>
 
-#include <soc/tegra/emc.h>
 #include <soc/tegra/fuse.h>
 #include <soc/tegra/mc.h>
 
@@ -562,8 +563,8 @@ static struct emc_timing *tegra_emc_find_timing(struct tegra_emc *emc,
 	return timing;
 }
 
-int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
-				    unsigned long rate)
+static int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
+					   unsigned long rate)
 {
 	struct emc_timing *timing = tegra_emc_find_timing(emc, rate);
 	struct emc_timing *last = &emc->last_timing;
@@ -790,8 +791,8 @@ int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
 	return 0;
 }
 
-void tegra_emc_complete_timing_change(struct tegra_emc *emc,
-				      unsigned long rate)
+static void tegra_emc_complete_timing_change(struct tegra_emc *emc,
+					     unsigned long rate)
 {
 	struct emc_timing *timing = tegra_emc_find_timing(emc, rate);
 	struct emc_timing *last = &emc->last_timing;
@@ -987,6 +988,7 @@ static const struct of_device_id tegra_emc_of_match[] = {
 	{ .compatible = "nvidia,tegra132-emc" },
 	{}
 };
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
 
 static struct device_node *
 tegra_emc_find_node_by_ram_code(struct device_node *node, u32 ram_code)
@@ -1252,9 +1254,20 @@ static int tegra_emc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, emc);
 
+	tegra124_clk_register_emc(pdev->dev.of_node,
+				  tegra_emc_prepare_timing_change,
+				  tegra_emc_complete_timing_change);
+
 	if (IS_ENABLED(CONFIG_DEBUG_FS))
 		emc_debugfs_init(&pdev->dev, emc);
 
+	/*
+	 * Don't allow the kernel module to be unloaded. Unloading adds some
+	 * extra complexity which doesn't really worth the effort in a case of
+	 * this driver.
+	 */
+	try_module_get(THIS_MODULE);
+
 	return 0;
 };
 
@@ -1266,9 +1279,8 @@ static struct platform_driver tegra_emc_driver = {
 		.suppress_bind_attrs = true,
 	},
 };
+module_platform_driver(tegra_emc_driver);
 
-static int tegra_emc_init(void)
-{
-	return platform_driver_register(&tegra_emc_driver);
-}
-subsys_initcall(tegra_emc_init);
+MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra124 EMC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/clk/tegra.h b/include/linux/clk/tegra.h
index 3f01d43f0598..797b8bde18de 100644
--- a/include/linux/clk/tegra.h
+++ b/include/linux/clk/tegra.h
@@ -136,6 +136,8 @@ extern void tegra210_clk_emc_dll_update_setting(u32 emc_dll_src_value);
 extern void tegra210_clk_emc_update_setting(u32 emc_src_value);
 
 struct clk;
+struct device_node;
+struct tegra_emc;
 
 typedef long (tegra20_clk_emc_round_cb)(unsigned long rate,
 					unsigned long min_rate,
@@ -146,6 +148,15 @@ void tegra20_clk_set_emc_round_callback(tegra20_clk_emc_round_cb *round_cb,
 					void *cb_arg);
 int tegra20_clk_prepare_emc_mc_same_freq(struct clk *emc_clk, bool same);
 
+typedef int (tegra124_emc_prepare_timing_change_cb)(struct tegra_emc *emc,
+						    unsigned long rate);
+typedef void (tegra124_emc_complete_timing_change_cb)(struct tegra_emc *emc,
+						      unsigned long rate);
+struct clk *
+tegra124_clk_register_emc(struct device_node *emc_np,
+			  tegra124_emc_prepare_timing_change_cb *prep_cb,
+			  tegra124_emc_complete_timing_change_cb *complete_cb);
+
 struct tegra210_clk_emc_config {
 	unsigned long rate;
 	bool same_freq;
diff --git a/include/soc/tegra/emc.h b/include/soc/tegra/emc.h
deleted file mode 100644
index 05199a97ccf4..000000000000
--- a/include/soc/tegra/emc.h
+++ /dev/null
@@ -1,16 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (c) 2014 NVIDIA Corporation. All rights reserved.
- */
-
-#ifndef __SOC_TEGRA_EMC_H__
-#define __SOC_TEGRA_EMC_H__
-
-struct tegra_emc;
-
-int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
-				    unsigned long rate);
-void tegra_emc_complete_timing_change(struct tegra_emc *emc,
-				      unsigned long rate);
-
-#endif /* __SOC_TEGRA_EMC_H__ */
-- 
2.27.0

[PATCH v5 07/36] memory: tegra124-emc: Use devm_platform_ioremap_resource

[Dmitry Osipenko]

Utilize that relatively new helper which makes code a bit cleaner.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/tegra124-emc.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index 93e9835e9761..8d7fc3fb00bb 100644
--- a/drivers/memory/tegra/tegra124-emc.c
+++ b/drivers/memory/tegra/tegra124-emc.c
@@ -1194,7 +1194,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	struct platform_device *mc;
 	struct device_node *np;
 	struct tegra_emc *emc;
-	struct resource *res;
 	u32 ram_code;
 	int err;
 
@@ -1204,8 +1203,7 @@ static int tegra_emc_probe(struct platform_device *pdev)
 
 	emc->dev = &pdev->dev;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	emc->regs = devm_ioremap_resource(&pdev->dev, res);
+	emc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(emc->regs))
 		return PTR_ERR(emc->regs);
 
-- 
2.27.0

[PATCH v5 08/36] soc/tegra: fuse: Export tegra_read_ram_code()

[Dmitry Osipenko]

The tegra_read_ram_code() is used by EMC drivers and we're going to make
these driver modular, hence this function needs to be exported.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/soc/tegra/fuse/tegra-apbmisc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/soc/tegra/fuse/tegra-apbmisc.c b/drivers/soc/tegra/fuse/tegra-apbmisc.c
index 8e416ad91ee2..151eccb6069d 100644
--- a/drivers/soc/tegra/fuse/tegra-apbmisc.c
+++ b/drivers/soc/tegra/fuse/tegra-apbmisc.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
  */
 
+#include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
@@ -65,6 +66,7 @@ u32 tegra_read_ram_code(void)
 
 	return straps >> PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT;
 }
+EXPORT_SYMBOL_GPL(tegra_read_ram_code);
 
 static const struct of_device_id apbmisc_match[] __initconst = {
 	{ .compatible = "nvidia,tegra20-apbmisc", },
-- 
2.27.0

[PATCH v5 09/36] memory: tegra20-emc: Initialize MC timings

[Dmitry Osipenko]

We're going to add interconnect support to the EMC driver. Once this
support will be added, the Tegra20 devfreq driver will no longer be
able to use clk_round_rate(emc) for building up OPP table. It's quite
handy that struct tegra_mc contains memory timings which could be used
by the devfreq drivers instead of the clk rate-rounding. The tegra_mc
timings are populated by the MC driver only for Tegra30+ SoCs, hence
the Tegra20 EMC could populate timings by itself.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/Kconfig       |  2 +-
 drivers/memory/tegra/tegra20-emc.c | 54 ++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index c1cad4ce6251..5bf75b316a2f 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -10,7 +10,7 @@ config TEGRA_MC
 config TEGRA20_EMC
 	tristate "NVIDIA Tegra20 External Memory Controller driver"
 	default y
-	depends on ARCH_TEGRA_2x_SOC
+	depends on TEGRA_MC && ARCH_TEGRA_2x_SOC
 	help
 	  This driver is for the External Memory Controller (EMC) found on
 	  Tegra20 chips. The EMC controls the external DRAM on the board.
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index 5aa3a1da2975..a02ffc09c39e 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -15,12 +15,15 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/sort.h>
 #include <linux/types.h>
 
 #include <soc/tegra/fuse.h>
 
+#include "mc.h"
+
 #define EMC_INTSTATUS				0x000
 #define EMC_INTMASK				0x004
 #define EMC_DBG					0x008
@@ -650,6 +653,45 @@ static void tegra_emc_debugfs_init(struct tegra_emc *emc)
 			    emc, &tegra_emc_debug_max_rate_fops);
 }
 
+static int tegra_emc_init_mc_timings(struct tegra_emc *emc)
+{
+	struct tegra_mc_timing *timing;
+	struct platform_device *pdev;
+	struct device_node *np;
+	struct tegra_mc *mc;
+	unsigned int i;
+
+	if (!emc->num_timings)
+		return 0;
+
+	np = of_find_compatible_node(NULL, NULL, "nvidia,tegra20-mc-gart");
+	if (!np)
+		return -ENOENT;
+
+	pdev = of_find_device_by_node(np);
+	of_node_put(np);
+	if (!pdev)
+		return -ENOENT;
+
+	mc = platform_get_drvdata(pdev);
+	if (!mc)
+		return -EPROBE_DEFER;
+
+	/* shouldn't happen */
+	WARN_ON(mc->num_timings);
+	WARN_ON(mc->timings);
+
+	mc->timings = devm_kcalloc(emc->dev, emc->num_timings, sizeof(*timing),
+				   GFP_KERNEL);
+	if (!mc->timings)
+		return -ENOMEM;
+
+	for (i = 0; i < emc->num_timings; i++, mc->num_timings++)
+		mc->timings[i].rate = emc->timings[i].rate;
+
+	return 0;
+}
+
 static int tegra_emc_probe(struct platform_device *pdev)
 {
 	struct device_node *np;
@@ -721,6 +763,18 @@ static int tegra_emc_probe(struct platform_device *pdev)
 		goto unset_cb;
 	}
 
+	/*
+	 * Only Tegra30+ SoCs are having Memory Controller timings initialized
+	 * by the MC driver. For Tegra20 we need to populate the MC timings
+	 * from here. The MC timings will be used by the Tegra20 devfreq driver.
+	 */
+	err = tegra_emc_init_mc_timings(emc);
+	if (err) {
+		dev_err(&pdev->dev, "failed to initialize mc timings: %d\n",
+			err);
+		goto unset_cb;
+	}
+
 	platform_set_drvdata(pdev, emc);
 	tegra_emc_debugfs_init(emc);
 
-- 
2.27.0

[PATCH v5 10/36] PM / devfreq: tegra20: Silence deferred probe error

[Dmitry Osipenko]

Tegra EMC driver was turned into a regular kernel driver, it also could
be compiled as a loadable kernel module now. Hence EMC clock isn't
guaranteed to be available and clk_get("emc") may return -EPROBE_DEFER and
there is no good reason to spam KMSG with a error about missing EMC clock
in this case, so let's silence the deferred probe error.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra20-devfreq.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/devfreq/tegra20-devfreq.c b/drivers/devfreq/tegra20-devfreq.c
index ff82bac9ee4e..6469dc69c5e0 100644
--- a/drivers/devfreq/tegra20-devfreq.c
+++ b/drivers/devfreq/tegra20-devfreq.c
@@ -141,9 +141,11 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 
 	/* EMC is a system-critical clock that is always enabled */
 	tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
-	if (IS_ERR(tegra->emc_clock)) {
-		err = PTR_ERR(tegra->emc_clock);
-		dev_err(&pdev->dev, "failed to get emc clock: %d\n", err);
+	err = PTR_ERR_OR_ZERO(tegra->emc_clock);
+	if (err) {
+		if (err != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "failed to get emc clock: %d\n",
+				err);
 		return err;
 	}
 
-- 
2.27.0

[PATCH v5 11/36] PM / devfreq: tegra30: Silence deferred probe error

[Dmitry Osipenko]

Tegra EMC driver was turned into a regular kernel driver, it also could
be compiled as a loadable kernel module now. Hence EMC clock isn't
guaranteed to be available and clk_get("emc") may return -EPROBE_DEFER and
there is no good reason to spam KMSG with a error about missing EMC clock
in this case, so let's silence the deferred probe error.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra30-devfreq.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index e94a27804c20..423dd35c95b3 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -801,9 +801,12 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 	}
 
 	tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
-	if (IS_ERR(tegra->emc_clock)) {
-		dev_err(&pdev->dev, "Failed to get emc clock\n");
-		return PTR_ERR(tegra->emc_clock);
+	err = PTR_ERR_OR_ZERO(tegra->emc_clock);
+	if (err) {
+		if (err != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Failed to get emc clock: %d\n",
+				err);
+		return err;
 	}
 
 	err = platform_get_irq(pdev, 0);
-- 
2.27.0

[PATCH v5 12/36] PM / devfreq: tegra20: Use MC timings for building OPP table

[Dmitry Osipenko]

The clk_round_rate() won't be usable for building OPP table once
interconnect support will be added to the EMC driver because that CLK API
function limits the rounded rate based on the clk rate that is imposed by
active clk-users, and thus, the rounding won't work as expected if
interconnect will set the minimum EMC clock rate before devfreq driver is
loaded. The struct tegra_mc contains memory timings which could be used by
the devfreq driver for building up OPP table instead of rounding clock
rate, this patch implements this idea.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra20-devfreq.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/devfreq/tegra20-devfreq.c b/drivers/devfreq/tegra20-devfreq.c
index 6469dc69c5e0..a985f24098f5 100644
--- a/drivers/devfreq/tegra20-devfreq.c
+++ b/drivers/devfreq/tegra20-devfreq.c
@@ -123,8 +123,7 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 {
 	struct tegra_devfreq *tegra;
 	struct tegra_mc *mc;
-	unsigned long max_rate;
-	unsigned long rate;
+	unsigned int i;
 	int err;
 
 	mc = tegra_get_memory_controller();
@@ -135,6 +134,11 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	if (!mc->num_timings) {
+		dev_info(&pdev->dev, "memory controller has no timings\n");
+		return -ENODEV;
+	}
+
 	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
 	if (!tegra)
 		return -ENOMEM;
@@ -151,12 +155,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 
 	tegra->regs = mc->regs;
 
-	max_rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
-
-	for (rate = 0; rate <= max_rate; rate++) {
-		rate = clk_round_rate(tegra->emc_clock, rate);
-
-		err = dev_pm_opp_add(&pdev->dev, rate, 0);
+	for (i = 0; i < mc->num_timings; i++) {
+		err = dev_pm_opp_add(&pdev->dev, mc->timings[i].rate, 0);
 		if (err) {
 			dev_err(&pdev->dev, "failed to add opp: %d\n", err);
 			goto remove_opps;
-- 
2.27.0

Re: [PATCH v5 12/36] PM / devfreq: tegra20: Use MC timings for building OPP table

[Chanwoo Choi]

Hi Dmitry,

On 8/14/20 9:05 AM, Dmitry Osipenko wrote:
> The clk_round_rate() won't be usable for building OPP table once
> interconnect support will be added to the EMC driver because that CLK API
> function limits the rounded rate based on the clk rate that is imposed by
> active clk-users, and thus, the rounding won't work as expected if
> interconnect will set the minimum EMC clock rate before devfreq driver is
> loaded. The struct tegra_mc contains memory timings which could be used by
> the devfreq driver for building up OPP table instead of rounding clock
> rate, this patch implements this idea.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/devfreq/tegra20-devfreq.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/devfreq/tegra20-devfreq.c b/drivers/devfreq/tegra20-devfreq.c
> index 6469dc69c5e0..a985f24098f5 100644
> --- a/drivers/devfreq/tegra20-devfreq.c
> +++ b/drivers/devfreq/tegra20-devfreq.c
> @@ -123,8 +123,7 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  {
>  	struct tegra_devfreq *tegra;
>  	struct tegra_mc *mc;
> -	unsigned long max_rate;
> -	unsigned long rate;
> +	unsigned int i;
>  	int err;
>  
>  	mc = tegra_get_memory_controller();
> @@ -135,6 +134,11 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  		return err;
>  	}
>  
> +	if (!mc->num_timings) {
> +		dev_info(&pdev->dev, "memory controller has no timings\n");
> +		return -ENODEV;
> +	}
> +
>  	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
>  	if (!tegra)
>  		return -ENOMEM;
> @@ -151,12 +155,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  
>  	tegra->regs = mc->regs;
>  
> -	max_rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
> -
> -	for (rate = 0; rate <= max_rate; rate++) {
> -		rate = clk_round_rate(tegra->emc_clock, rate);
> -
> -		err = dev_pm_opp_add(&pdev->dev, rate, 0);
> +	for (i = 0; i < mc->num_timings; i++) {
> +		err = dev_pm_opp_add(&pdev->dev, mc->timings[i].rate, 0);
>  		if (err) {
>  			dev_err(&pdev->dev, "failed to add opp: %d\n", err);
>  			goto remove_opps;
> 

Ackded-by: Chanwoo Choi <cw00.choi@samsung.com>

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

[PATCH v5 13/36] PM / devfreq: tegra30: Use MC timings for building OPP table

[Dmitry Osipenko]

The clk_round_rate() won't be usable for building OPP table once
interconnect support will be added to the EMC driver because that CLK API
function limits the rounded rate based on the clk rate that is imposed by
active clk-users, and thus, the rounding won't work as expected if
interconnect will set the minimum EMC clock rate before devfreq driver is
loaded. The struct tegra_mc contains memory timings which could be used by
the devfreq driver for building up OPP table instead of rounding clock
rate, this patch implements this idea.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra30-devfreq.c | 93 +++++++++++++++++++++----------
 1 file changed, 65 insertions(+), 28 deletions(-)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index 423dd35c95b3..6c2f56b34535 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -19,6 +19,8 @@
 #include <linux/reset.h>
 #include <linux/workqueue.h>
 
+#include <soc/tegra/mc.h>
+
 #include "governor.h"
 
 #define ACTMON_GLB_STATUS					0x0
@@ -153,6 +155,18 @@ struct tegra_devfreq_device {
 	unsigned long target_freq;
 };
 
+struct tegra_devfreq_soc_data {
+	const char *mc_compatible;
+};
+
+static const struct tegra_devfreq_soc_data tegra30_soc = {
+	.mc_compatible = "nvidia,tegra30-mc",
+};
+
+static const struct tegra_devfreq_soc_data tegra124_soc = {
+	.mc_compatible = "nvidia,tegra124-mc",
+};
+
 struct tegra_devfreq {
 	struct devfreq		*devfreq;
 
@@ -771,15 +785,49 @@ static struct devfreq_governor tegra_devfreq_governor = {
 	.interrupt_driven = true,
 };
 
+static struct tegra_mc *tegra_get_memory_controller(const char *compatible)
+{
+	struct platform_device *pdev;
+	struct device_node *np;
+	struct tegra_mc *mc;
+
+	np = of_find_compatible_node(NULL, NULL, compatible);
+	if (!np)
+		return ERR_PTR(-ENOENT);
+
+	pdev = of_find_device_by_node(np);
+	of_node_put(np);
+	if (!pdev)
+		return ERR_PTR(-ENODEV);
+
+	mc = platform_get_drvdata(pdev);
+	if (!mc)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	return mc;
+}
+
 static int tegra_devfreq_probe(struct platform_device *pdev)
 {
+	const struct tegra_devfreq_soc_data *soc_data;
 	struct tegra_devfreq_device *dev;
 	struct tegra_devfreq *tegra;
 	struct devfreq *devfreq;
+	struct tegra_mc *mc;
 	unsigned int i;
-	long rate;
 	int err;
 
+	soc_data = of_device_get_match_data(&pdev->dev);
+
+	mc = tegra_get_memory_controller(soc_data->mc_compatible);
+	if (IS_ERR(mc))
+		return PTR_ERR(mc);
+
+	if (!mc->num_timings) {
+		dev_info(&pdev->dev, "memory controller has no timings\n");
+		return -ENODEV;
+	}
+
 	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
 	if (!tegra)
 		return -ENOMEM;
@@ -825,6 +873,20 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	for (i = 0; i < mc->num_timings; i++) {
+		/*
+		 * Memory Controller timings are sorted in ascending clock
+		 * rate order, so the last timing will be the max freq.
+		 */
+		tegra->max_freq = mc->timings[i].rate / KHZ;
+
+		err = dev_pm_opp_add(&pdev->dev, tegra->max_freq, 0);
+		if (err) {
+			dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
+			goto remove_opps;
+		}
+	}
+
 	reset_control_assert(tegra->reset);
 
 	err = clk_prepare_enable(tegra->clock);
@@ -836,37 +898,12 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 
 	reset_control_deassert(tegra->reset);
 
-	rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
-	if (rate < 0) {
-		dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
-		return rate;
-	}
-
-	tegra->max_freq = rate / KHZ;
-
 	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
 		dev = tegra->devices + i;
 		dev->config = actmon_device_configs + i;
 		dev->regs = tegra->regs + dev->config->offset;
 	}
 
-	for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
-		rate = clk_round_rate(tegra->emc_clock, rate);
-
-		if (rate < 0) {
-			dev_err(&pdev->dev,
-				"Failed to round clock rate: %ld\n", rate);
-			err = rate;
-			goto remove_opps;
-		}
-
-		err = dev_pm_opp_add(&pdev->dev, rate / KHZ, 0);
-		if (err) {
-			dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
-			goto remove_opps;
-		}
-	}
-
 	platform_set_drvdata(pdev, tegra);
 
 	tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb;
@@ -921,8 +958,8 @@ static int tegra_devfreq_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id tegra_devfreq_of_match[] = {
-	{ .compatible = "nvidia,tegra30-actmon" },
-	{ .compatible = "nvidia,tegra124-actmon" },
+	{ .compatible = "nvidia,tegra30-actmon",  .data = &tegra30_soc, },
+	{ .compatible = "nvidia,tegra124-actmon", .data = &tegra124_soc, },
 	{ },
 };
 
-- 
2.27.0

Re: [PATCH v5 13/36] PM / devfreq: tegra30: Use MC timings for building OPP table

[Chanwoo Choi]

Hi Dmitry,

I add the minor comment. Except of some comments, it looks good to me.

On 8/14/20 9:05 AM, Dmitry Osipenko wrote:
> The clk_round_rate() won't be usable for building OPP table once
> interconnect support will be added to the EMC driver because that CLK API
> function limits the rounded rate based on the clk rate that is imposed by
> active clk-users, and thus, the rounding won't work as expected if
> interconnect will set the minimum EMC clock rate before devfreq driver is
> loaded. The struct tegra_mc contains memory timings which could be used by
> the devfreq driver for building up OPP table instead of rounding clock
> rate, this patch implements this idea.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/devfreq/tegra30-devfreq.c | 93 +++++++++++++++++++++----------
>  1 file changed, 65 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index 423dd35c95b3..6c2f56b34535 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -19,6 +19,8 @@
>  #include <linux/reset.h>
>  #include <linux/workqueue.h>
>  
> +#include <soc/tegra/mc.h>
> +
>  #include "governor.h"
>  
>  #define ACTMON_GLB_STATUS					0x0
> @@ -153,6 +155,18 @@ struct tegra_devfreq_device {
>  	unsigned long target_freq;
>  };
>  
> +struct tegra_devfreq_soc_data {
> +	const char *mc_compatible;
> +};
> +
> +static const struct tegra_devfreq_soc_data tegra30_soc = {
> +	.mc_compatible = "nvidia,tegra30-mc",
> +};
> +
> +static const struct tegra_devfreq_soc_data tegra124_soc = {
> +	.mc_compatible = "nvidia,tegra124-mc",
> +};
> +
>  struct tegra_devfreq {
>  	struct devfreq		*devfreq;
>  
> @@ -771,15 +785,49 @@ static struct devfreq_governor tegra_devfreq_governor = {
>  	.interrupt_driven = true,
>  };
>  
> +static struct tegra_mc *tegra_get_memory_controller(const char *compatible)
> +{
> +	struct platform_device *pdev;
> +	struct device_node *np;
> +	struct tegra_mc *mc;
> +
> +	np = of_find_compatible_node(NULL, NULL, compatible);
> +	if (!np)
> +		return ERR_PTR(-ENOENT);
> +
> +	pdev = of_find_device_by_node(np);
> +	of_node_put(np);
> +	if (!pdev)
> +		return ERR_PTR(-ENODEV);
> +
> +	mc = platform_get_drvdata(pdev);
> +	if (!mc)
> +		return ERR_PTR(-EPROBE_DEFER);
> +
> +	return mc;
> +}
> +
>  static int tegra_devfreq_probe(struct platform_device *pdev)
>  {
> +	const struct tegra_devfreq_soc_data *soc_data;
>  	struct tegra_devfreq_device *dev;
>  	struct tegra_devfreq *tegra;
>  	struct devfreq *devfreq;
> +	struct tegra_mc *mc;
>  	unsigned int i;
> -	long rate;
>  	int err;
>  
> +	soc_data = of_device_get_match_data(&pdev->dev);

I think that better to check whether 'soc_data' is not NULL.


> +
> +	mc = tegra_get_memory_controller(soc_data->mc_compatible);
> +	if (IS_ERR(mc))
> +		return PTR_ERR(mc);

You better to add error log.

> +
> +	if (!mc->num_timings) {
> +		dev_info(&pdev->dev, "memory controller has no timings\n");
> +		return -ENODEV;
> +	}
> +
>  	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
>  	if (!tegra)
>  		return -ENOMEM;
> @@ -825,6 +873,20 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  		return err;
>  	}
>  
> +	for (i = 0; i < mc->num_timings; i++) {
> +		/*
> +		 * Memory Controller timings are sorted in ascending clock
> +		 * rate order, so the last timing will be the max freq.
> +		 */
> +		tegra->max_freq = mc->timings[i].rate / KHZ;
> +
> +		err = dev_pm_opp_add(&pdev->dev, tegra->max_freq, 0);
> +		if (err) {
> +			dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
> +			goto remove_opps;
> +		}
> +	}
> +
>  	reset_control_assert(tegra->reset);
>  
>  	err = clk_prepare_enable(tegra->clock);
> @@ -836,37 +898,12 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  
>  	reset_control_deassert(tegra->reset);
>  
> -	rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
> -	if (rate < 0) {
> -		dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
> -		return rate;
> -	}
> -
> -	tegra->max_freq = rate / KHZ;
> -
>  	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
>  		dev = tegra->devices + i;
>  		dev->config = actmon_device_configs + i;
>  		dev->regs = tegra->regs + dev->config->offset;
>  	}
>  
> -	for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
> -		rate = clk_round_rate(tegra->emc_clock, rate);
> -
> -		if (rate < 0) {
> -			dev_err(&pdev->dev,
> -				"Failed to round clock rate: %ld\n", rate);
> -			err = rate;
> -			goto remove_opps;
> -		}
> -
> -		err = dev_pm_opp_add(&pdev->dev, rate / KHZ, 0);
> -		if (err) {
> -			dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
> -			goto remove_opps;
> -		}
> -	}
> -
>  	platform_set_drvdata(pdev, tegra);
>  
>  	tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb;
> @@ -921,8 +958,8 @@ static int tegra_devfreq_remove(struct platform_device *pdev)
>  }
>  
>  static const struct of_device_id tegra_devfreq_of_match[] = {
> -	{ .compatible = "nvidia,tegra30-actmon" },
> -	{ .compatible = "nvidia,tegra124-actmon" },
> +	{ .compatible = "nvidia,tegra30-actmon",  .data = &tegra30_soc, },
> +	{ .compatible = "nvidia,tegra124-actmon", .data = &tegra124_soc, },
>  	{ },
>  };
>  
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [PATCH v5 13/36] PM / devfreq: tegra30: Use MC timings for building OPP table

[Dmitry Osipenko]

14.08.2020 05:02, Chanwoo Choi пишет:
> Hi Dmitry,
> 
> I add the minor comment. Except of some comments, it looks good to me.

Hello, Chanwoo! Thank you for the review!

...
>> +struct tegra_devfreq_soc_data {
>> +	const char *mc_compatible;
>> +};
>> +
>> +static const struct tegra_devfreq_soc_data tegra30_soc = {
>> +	.mc_compatible = "nvidia,tegra30-mc",
>> +};
>> +
>> +static const struct tegra_devfreq_soc_data tegra124_soc = {
>> +	.mc_compatible = "nvidia,tegra124-mc",
>> +};
.
>> +	soc_data = of_device_get_match_data(&pdev->dev);
> 
> I think that better to check whether 'soc_data' is not NULL.

It's a quite common misconception among kernel developers that
of_device_get_match_data() may "accidentally" return NULL, but it
couldn't if every driver's of_match[] entry has a non-NULL .data field
and because the OF-matching already happened at the driver's probe-time
[1], which is the case of this driver.

[1] https://elixir.bootlin.com/linux/v5.8/source/drivers/of/device.c#L189

Hence the NULL-checking is unnecessary.

When I first encountered the of_device_get_match_data(), I was also
thinking that adding the NULL-checks is a good idea, but later on
somebody pointed out to me (maybe Thierry) that it's unnecessary to do.

>> +
>> +	mc = tegra_get_memory_controller(soc_data->mc_compatible);
>> +	if (IS_ERR(mc))
>> +		return PTR_ERR(mc);
> 
> You better to add error log.

In practice we should get only -EPROBE_DEFER here ever. I'll consider
adding the message in the next revision, at least just for consistency.

Thanks!

...
>>  static const struct of_device_id tegra_devfreq_of_match[] = {
>> -	{ .compatible = "nvidia,tegra30-actmon" },
>> -	{ .compatible = "nvidia,tegra124-actmon" },
>> +	{ .compatible = "nvidia,tegra30-actmon",  .data = &tegra30_soc, },
>> +	{ .compatible = "nvidia,tegra124-actmon", .data = &tegra124_soc, },
>>  	{ },
>>  };

Re: [PATCH v5 13/36] PM / devfreq: tegra30: Use MC timings for building OPP table

[Chanwoo Choi]

Hi,

On 8/15/20 1:47 AM, Dmitry Osipenko wrote:
> 14.08.2020 05:02, Chanwoo Choi пишет:
>> Hi Dmitry,
>>
>> I add the minor comment. Except of some comments, it looks good to me.
> 
> Hello, Chanwoo! Thank you for the review!
> 
> ...
>>> +struct tegra_devfreq_soc_data {
>>> +	const char *mc_compatible;
>>> +};
>>> +
>>> +static const struct tegra_devfreq_soc_data tegra30_soc = {
>>> +	.mc_compatible = "nvidia,tegra30-mc",
>>> +};
>>> +
>>> +static const struct tegra_devfreq_soc_data tegra124_soc = {
>>> +	.mc_compatible = "nvidia,tegra124-mc",
>>> +};
> .
>>> +	soc_data = of_device_get_match_data(&pdev->dev);
>>
>> I think that better to check whether 'soc_data' is not NULL.
> 
> It's a quite common misconception among kernel developers that
> of_device_get_match_data() may "accidentally" return NULL, but it
> couldn't if every driver's of_match[] entry has a non-NULL .data field
> and because the OF-matching already happened at the driver's probe-time
> [1], which is the case of this driver.
> 
> [1] https://elixir.bootlin.com/linux/v5.8/source/drivers/of/device.c#L189
> 
> Hence the NULL-checking is unnecessary.
> 
> When I first encountered the of_device_get_match_data(), I was also
> thinking that adding the NULL-checks is a good idea, but later on
> somebody pointed out to me (maybe Thierry) that it's unnecessary to do.

OK. Thanks.

> 
>>> +
>>> +	mc = tegra_get_memory_controller(soc_data->mc_compatible);
>>> +	if (IS_ERR(mc))
>>> +		return PTR_ERR(mc);
>>
>> You better to add error log.
> 
> In practice we should get only -EPROBE_DEFER here ever. I'll consider
> adding the message in the next revision, at least just for consistency.

In order to handle -EPROBE_DEFER, recommend the using of dev_err_probe().

(snip)

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [PATCH v5 13/36] PM / devfreq: tegra30: Use MC timings for building OPP table

[Dmitry Osipenko]

28.08.2020 04:47, Chanwoo Choi пишет:
> Hi,
...
>> Hence the NULL-checking is unnecessary.
>>
>> When I first encountered the of_device_get_match_data(), I was also
>> thinking that adding the NULL-checks is a good idea, but later on
>> somebody pointed out to me (maybe Thierry) that it's unnecessary to do.
> 
> OK. Thanks.
> 
>>
>>>> +
>>>> +	mc = tegra_get_memory_controller(soc_data->mc_compatible);
>>>> +	if (IS_ERR(mc))
>>>> +		return PTR_ERR(mc);
>>>
>>> You better to add error log.
>>
>> In practice we should get only -EPROBE_DEFER here ever. I'll consider
>> adding the message in the next revision, at least just for consistency.
> 
> In order to handle -EPROBE_DEFER, recommend the using of dev_err_probe().

Hello, Chanwoo!

Thank you for the suggestion! I wasn't aware about the dev_err_probe()
until recently and will use this new helper in the v6!

Thanks!

[PATCH v5 14/36] PM / devfreq: tegra20: Add error messages to tegra_devfreq_target()

[Dmitry Osipenko]

It's useful to now when something goes wrong instead of failing silently,
so let's add error messages to tegra_devfreq_target() to prevent situation
where it fails silently.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra20-devfreq.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/devfreq/tegra20-devfreq.c b/drivers/devfreq/tegra20-devfreq.c
index a985f24098f5..bc43284996de 100644
--- a/drivers/devfreq/tegra20-devfreq.c
+++ b/drivers/devfreq/tegra20-devfreq.c
@@ -44,19 +44,25 @@ static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
 	int err;
 
 	opp = devfreq_recommended_opp(dev, freq, flags);
-	if (IS_ERR(opp))
+	if (IS_ERR(opp)) {
+		dev_err(dev, "failed to find opp for %lu Hz\n", *freq);
 		return PTR_ERR(opp);
+	}
 
 	rate = dev_pm_opp_get_freq(opp);
 	dev_pm_opp_put(opp);
 
 	err = clk_set_min_rate(tegra->emc_clock, rate);
-	if (err)
+	if (err) {
+		dev_err(dev, "failed to set min rate: %d\n", err);
 		return err;
+	}
 
 	err = clk_set_rate(tegra->emc_clock, 0);
-	if (err)
+	if (err) {
+		dev_err(dev, "failed to set rate: %d\n", err);
 		goto restore_min_rate;
+	}
 
 	return 0;
 
-- 
2.27.0

[PATCH v5 15/36] PM / devfreq: tegra30: Add error messages to tegra_devfreq_target()

[Dmitry Osipenko]

It's useful to now when something goes wrong instead of failing silently,
so let's add error messages to tegra_devfreq_target() to prevent situation
where it fails silently.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra30-devfreq.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index 6c2f56b34535..a0d6f628aaa4 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -641,12 +641,16 @@ static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
 	dev_pm_opp_put(opp);
 
 	err = clk_set_min_rate(tegra->emc_clock, rate * KHZ);
-	if (err)
+	if (err) {
+		dev_err(dev, "Failed to set min rate: %d\n", err);
 		return err;
+	}
 
 	err = clk_set_rate(tegra->emc_clock, 0);
-	if (err)
+	if (err) {
+		dev_err(dev, "Failed to set rate: %d\n", err);
 		goto restore_min_rate;
+	}
 
 	return 0;
 
-- 
2.27.0

[PATCH v5 16/36] PM / devfreq: tegra20: Adjust clocks conversion ratio and polling interval

[Dmitry Osipenko]

The current conversion ratio results in a higher frequency than needed,
that is not very actual now since the Display Controller driver got
support for memory bandwidth management and hence memory frequency can
go lower now without bad consequences. Since memory freq now goes to a
lower rates, the responsiveness of interactive applications become worse
due to a quite high polling interval value that is currently set to 500ms.
Changing polling interval to 30ms results in a good responsiveness of the
system.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra20-devfreq.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/devfreq/tegra20-devfreq.c b/drivers/devfreq/tegra20-devfreq.c
index bc43284996de..ebfc5ac9e5c3 100644
--- a/drivers/devfreq/tegra20-devfreq.c
+++ b/drivers/devfreq/tegra20-devfreq.c
@@ -79,16 +79,12 @@ static int tegra_devfreq_get_dev_status(struct device *dev,
 
 	/*
 	 * EMC_COUNT returns number of memory events, that number is lower
-	 * than the number of clocks. Conversion ratio of 1/8 results in a
-	 * bit higher bandwidth than actually needed, it is good enough for
-	 * the time being because drivers don't support requesting minimum
-	 * needed memory bandwidth yet.
-	 *
-	 * TODO: adjust the ratio value once relevant drivers will support
-	 * memory bandwidth management.
+	 * than the number of total EMC clocks over the sampling period.
+	 * The clocks number is converted to maximum possible number of
+	 * memory events using the ratio of 1/4.
 	 */
 	stat->busy_time = readl_relaxed(tegra->regs + MC_STAT_EMC_COUNT);
-	stat->total_time = readl_relaxed(tegra->regs + MC_STAT_EMC_CLOCKS) / 8;
+	stat->total_time = readl_relaxed(tegra->regs + MC_STAT_EMC_CLOCKS) / 4;
 	stat->current_frequency = clk_get_rate(tegra->emc_clock);
 
 	writel_relaxed(EMC_GATHER_CLEAR, tegra->regs + MC_STAT_CONTROL);
@@ -98,7 +94,7 @@ static int tegra_devfreq_get_dev_status(struct device *dev,
 }
 
 static struct devfreq_dev_profile tegra_devfreq_profile = {
-	.polling_ms	= 500,
+	.polling_ms	= 30,
 	.target		= tegra_devfreq_target,
 	.get_dev_status	= tegra_devfreq_get_dev_status,
 };
-- 
2.27.0

[PATCH v5 17/36] PM / devfreq: tegra20: Relax Kconfig dependency

[Dmitry Osipenko]

The Tegra EMC driver now could be compiled as a loadable kernel module.
Currently devfreq driver depends on the EMC/MC drivers in Kconfig, and
thus, devfreq is forced to be a kernel module if EMC is compiled as a
module. This build dependency could be relaxed since devfreq driver
checks MC/EMC presence on probe, allowing kernel configuration where
devfreq is a built-in driver and EMC driver is a loadable module.
This change puts Tegra20 devfreq Kconfig entry on a par with the Tegra30
devfreq entry.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index 37dc40d1fcfb..0ee36ae2fa79 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -123,7 +123,7 @@ config ARM_TEGRA_DEVFREQ
 
 config ARM_TEGRA20_DEVFREQ
 	tristate "NVIDIA Tegra20 DEVFREQ Driver"
-	depends on (TEGRA_MC && TEGRA20_EMC) || COMPILE_TEST
+	depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
 	depends on COMMON_CLK
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
 	help
-- 
2.27.0

[PATCH v5 18/36] dt-bindings: memory: tegra20: mc: Document new interconnect property

[Dmitry Osipenko]

Memory controller is interconnected with memory clients and with the
external memory controller. Document new interconnect property which
turns memory controller into interconnect provider.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../bindings/memory-controllers/nvidia,tegra20-mc.txt          | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-mc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-mc.txt
index e55328237df4..739b7c6f2e26 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-mc.txt
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-mc.txt
@@ -16,6 +16,8 @@ Required properties:
   IOMMU specifier needed to encode an address. GART supports only a single
   address space that is shared by all devices, therefore no additional
   information needed for the address encoding.
+- #interconnect-cells : Should be 1. This cell represents memory client.
+  The assignments may be found in header file <dt-bindings/memory/tegra20-mc.h>.
 
 Example:
 	mc: memory-controller@7000f000 {
@@ -27,6 +29,7 @@ Example:
 		interrupts = <GIC_SPI 77 0x04>;
 		#reset-cells = <1>;
 		#iommu-cells = <0>;
+		#interconnect-cells = <1>;
 	};
 
 	video-codec@6001a000 {
-- 
2.27.0

[PATCH v5 19/36] dt-bindings: memory: tegra20: emc: Document new interconnect property

[Dmitry Osipenko]

External memory controller is interconnected with memory controller and
with external memory. Document new interconnect property which turns
external memory controller into interconnect provider.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../bindings/memory-controllers/nvidia,tegra20-emc.txt          | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt
index add95367640b..f51da7662de4 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt
@@ -12,6 +12,7 @@ Properties:
   irrespective of ram-code configuration.
 - interrupts : Should contain EMC General interrupt.
 - clocks : Should contain EMC clock.
+- #interconnect-cells : Should be 0.
 
 Child device nodes describe the memory settings for different configurations and clock rates.
 
@@ -20,6 +21,7 @@ Example:
 	memory-controller@7000f400 {
 		#address-cells = < 1 >;
 		#size-cells = < 0 >;
+		#interconnect-cells = < 0 >;
 		compatible = "nvidia,tegra20-emc";
 		reg = <0x7000f4000 0x200>;
 		interrupts = <0 78 0x04>;
-- 
2.27.0

[PATCH v5 20/36] dt-bindings: memory: tegra30: mc: Document new interconnect property

[Dmitry Osipenko]

Memory controller is interconnected with memory clients and with the
external memory controller. Document new interconnect property which
turns memory controller into interconnect provider.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../bindings/memory-controllers/nvidia,tegra30-mc.yaml       | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-mc.yaml b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-mc.yaml
index 84fd57bcf0dc..5436e6d420bc 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-mc.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-mc.yaml
@@ -57,6 +57,9 @@ properties:
   "#iommu-cells":
     const: 1
 
+  "#interconnect-cells":
+    const: 1
+
 patternProperties:
   "^emc-timings-[0-9]+$":
     type: object
@@ -120,6 +123,7 @@ required:
   - clock-names
   - "#reset-cells"
   - "#iommu-cells"
+  - "#interconnect-cells"
 
 additionalProperties: false
 
@@ -135,6 +139,7 @@ examples:
 
         #iommu-cells = <1>;
         #reset-cells = <1>;
+        #interconnect-cells = <1>;
 
         emc-timings-1 {
             nvidia,ram-code = <1>;
-- 
2.27.0

[PATCH v5 21/36] dt-bindings: memory: tegra30: emc: Document new interconnect property

[Dmitry Osipenko]

External memory controller is interconnected with memory controller and
with external memory. Document new interconnect property which turns
external memory controller into interconnect provider.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../bindings/memory-controllers/nvidia,tegra30-emc.yaml     | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-emc.yaml b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-emc.yaml
index 112bae2fcbbd..c243986db420 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-emc.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-emc.yaml
@@ -31,6 +31,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  "#interconnect-cells":
+    const: 0
+
   nvidia,memory-controller:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
@@ -214,6 +217,7 @@ required:
   - interrupts
   - clocks
   - nvidia,memory-controller
+  - "#interconnect-cells"
 
 additionalProperties: false
 
@@ -227,6 +231,8 @@ examples:
 
         nvidia,memory-controller = <&mc>;
 
+        #interconnect-cells = <0>;
+
         emc-timings-1 {
             nvidia,ram-code = <1>;
 
-- 
2.27.0

[PATCH v5 22/36] dt-bindings: host1x: Document new interconnect properties

[Dmitry Osipenko]

Most of Host1x devices have at least one memory client. These clients
are directly connected to the memory controller. The new interconnect
properties represent the memory client's connection to the memory
controller.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../display/tegra/nvidia,tegra20-host1x.txt   | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt
index 47319214b5f6..dd94b8bf4ae3 100644
--- a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt
+++ b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt
@@ -20,6 +20,10 @@ Required properties:
 - reset-names: Must include the following entries:
   - host1x
 
+Each host1x client module having to perform DMA through the Memory Controller
+should have the interconnect endpoints set to the Memory Client and External
+Memory respectively.
+
 The host1x top-level node defines a number of children, each representing one
 of the following host1x client modules:
 
@@ -36,6 +40,12 @@ of the following host1x client modules:
   - reset-names: Must include the following entries:
     - mpe
 
+  Optional properties:
+  - interconnects: Must contain entry for the MPE memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
+
 - vi: video input
 
   Required properties:
@@ -65,6 +75,12 @@ of the following host1x client modules:
       - power-domains: Must include sor powergate node as csicil is in
         SOR partition.
 
+  Optional properties:
+  - interconnects: Must contain entry for the VI memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
+
 - epp: encoder pre-processor
 
   Required properties:
@@ -78,6 +94,12 @@ of the following host1x client modules:
   - reset-names: Must include the following entries:
     - epp
 
+  Optional properties:
+  - interconnects: Must contain entry for the EPP memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
+
 - isp: image signal processor
 
   Required properties:
@@ -91,6 +113,12 @@ of the following host1x client modules:
   - reset-names: Must include the following entries:
     - isp
 
+  Optional properties:
+  - interconnects: Must contain entry for the ISP memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
+
 - gr2d: 2D graphics engine
 
   Required properties:
@@ -104,6 +132,12 @@ of the following host1x client modules:
   - reset-names: Must include the following entries:
     - 2d
 
+  Optional properties:
+  - interconnects: Must contain entry for the GR2D memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
+
 - gr3d: 3D graphics engine
 
   Required properties:
@@ -122,6 +156,12 @@ of the following host1x client modules:
     - 3d
     - 3d2 (Only required on SoCs with two 3D clocks)
 
+  Optional properties:
+  - interconnects: Must contain entry for the GR3D memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
+
 - dc: display controller
 
   Required properties:
@@ -149,6 +189,10 @@ of the following host1x client modules:
   - nvidia,hpd-gpio: specifies a GPIO used for hotplug detection
   - nvidia,edid: supplies a binary EDID blob
   - nvidia,panel: phandle of a display panel
+  - interconnects: Must contain entry for the DC memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
 
 - hdmi: High Definition Multimedia Interface
 
@@ -297,6 +341,12 @@ of the following host1x client modules:
   - reset-names: Must include the following entries:
     - vic
 
+  Optional properties:
+  - interconnects: Must contain entry for the VIC memory clients.
+  - interconnect-names: Must include name of the interconnect path for each
+    interconnect entry. Consult TRM documentation for information about
+    available memory clients, see MEMORY CONTROLLER section.
+
 Example:
 
 / {
@@ -410,6 +460,15 @@ Example:
 			resets = <&tegra_car 27>;
 			reset-names = "dc";
 
+			interconnects = <&mc TEGRA20_MC_DISPLAY0A &emc>,
+					<&mc TEGRA20_MC_DISPLAY0B &emc>,
+					<&mc TEGRA20_MC_DISPLAY0C &emc>,
+					<&mc TEGRA20_MC_DISPLAY1B &emc>;
+			interconnect-names = "wina",
+					     "winb",
+					     "winc",
+					     "cursor";
+
 			rgb {
 				status = "disabled";
 			};
@@ -425,6 +484,15 @@ Example:
 			resets = <&tegra_car 26>;
 			reset-names = "dc";
 
+			interconnects = <&mc TEGRA20_MC_DISPLAY0AB &emc>,
+					<&mc TEGRA20_MC_DISPLAY0BB &emc>,
+					<&mc TEGRA20_MC_DISPLAY0CB &emc>,
+					<&mc TEGRA20_MC_DISPLAY1BB &emc>;
+			interconnect-names = "wina",
+					     "winb",
+					     "winc",
+					     "cursor";
+
 			rgb {
 				status = "disabled";
 			};
-- 
2.27.0

Re: [PATCH v5 22/36] dt-bindings: host1x: Document new interconnect properties

[Rob Herring]

On Fri, 14 Aug 2020 03:06:07 +0300, Dmitry Osipenko wrote:
> Most of Host1x devices have at least one memory client. These clients
> are directly connected to the memory controller. The new interconnect
> properties represent the memory client's connection to the memory
> controller.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../display/tegra/nvidia,tegra20-host1x.txt   | 68 +++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v5 23/36] dt-bindings: memory: tegra20: Add memory client IDs

[Dmitry Osipenko]

Each memory client have a unique hardware ID, this patch adds these IDs.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 include/dt-bindings/memory/tegra20-mc.h | 53 +++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/include/dt-bindings/memory/tegra20-mc.h b/include/dt-bindings/memory/tegra20-mc.h
index 35e131eee198..6f8829508ad0 100644
--- a/include/dt-bindings/memory/tegra20-mc.h
+++ b/include/dt-bindings/memory/tegra20-mc.h
@@ -18,4 +18,57 @@
 #define TEGRA20_MC_RESET_VDE		13
 #define TEGRA20_MC_RESET_VI		14
 
+#define TEGRA20_MC_DISPLAY0A		0
+#define TEGRA20_MC_DISPLAY0AB		1
+#define TEGRA20_MC_DISPLAY0B		2
+#define TEGRA20_MC_DISPLAY0BB		3
+#define TEGRA20_MC_DISPLAY0C		4
+#define TEGRA20_MC_DISPLAY0CB		5
+#define TEGRA20_MC_DISPLAY1B		6
+#define TEGRA20_MC_DISPLAY1BB		7
+#define TEGRA20_MC_EPPUP		8
+#define TEGRA20_MC_G2PR			9
+#define TEGRA20_MC_G2SR			10
+#define TEGRA20_MC_MPEUNIFBR		11
+#define TEGRA20_MC_VIRUV		12
+#define TEGRA20_MC_AVPCARM7R		13
+#define TEGRA20_MC_DISPLAYHC		14
+#define TEGRA20_MC_DISPLAYHCB		15
+#define TEGRA20_MC_FDCDRD		16
+#define TEGRA20_MC_G2DR			17
+#define TEGRA20_MC_HOST1XDMAR		18
+#define TEGRA20_MC_HOST1XR		19
+#define TEGRA20_MC_IDXSRD		20
+#define TEGRA20_MC_MPCORER		21
+#define TEGRA20_MC_MPE_IPRED		22
+#define TEGRA20_MC_MPEAMEMRD		23
+#define TEGRA20_MC_MPECSRD		24
+#define TEGRA20_MC_PPCSAHBDMAR		25
+#define TEGRA20_MC_PPCSAHBSLVR		26
+#define TEGRA20_MC_TEXSRD		27
+#define TEGRA20_MC_VDEBSEVR		28
+#define TEGRA20_MC_VDEMBER		29
+#define TEGRA20_MC_VDEMCER		30
+#define TEGRA20_MC_VDETPER		31
+#define TEGRA20_MC_EPPU			32
+#define TEGRA20_MC_EPPV			33
+#define TEGRA20_MC_EPPY			34
+#define TEGRA20_MC_MPEUNIFBW		35
+#define TEGRA20_MC_VIWSB		36
+#define TEGRA20_MC_VIWU			37
+#define TEGRA20_MC_VIWV			38
+#define TEGRA20_MC_VIWY			39
+#define TEGRA20_MC_G2DW			40
+#define TEGRA20_MC_AVPCARM7W		41
+#define TEGRA20_MC_FDCDWR		42
+#define TEGRA20_MC_HOST1XW		43
+#define TEGRA20_MC_ISPW			44
+#define TEGRA20_MC_MPCOREW		45
+#define TEGRA20_MC_MPECSWR		46
+#define TEGRA20_MC_PPCSAHBDMAW		47
+#define TEGRA20_MC_PPCSAHBSLVW		48
+#define TEGRA20_MC_VDEBSEVW		49
+#define TEGRA20_MC_VDEMBEW		50
+#define TEGRA20_MC_VDETPMW		51
+
 #endif
-- 
2.27.0

[PATCH v5 24/36] dt-bindings: memory: tegra30: Add memory client IDs

[Dmitry Osipenko]

Each memory client have a unique hardware ID, this patch adds these IDs.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 include/dt-bindings/memory/tegra30-mc.h | 67 +++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/include/dt-bindings/memory/tegra30-mc.h b/include/dt-bindings/memory/tegra30-mc.h
index 169f005fbc78..930f708aca17 100644
--- a/include/dt-bindings/memory/tegra30-mc.h
+++ b/include/dt-bindings/memory/tegra30-mc.h
@@ -41,4 +41,71 @@
 #define TEGRA30_MC_RESET_VDE		16
 #define TEGRA30_MC_RESET_VI		17
 
+#define TEGRA30_MC_PTCR			0
+#define TEGRA30_MC_DISPLAY0A		1
+#define TEGRA30_MC_DISPLAY0AB		2
+#define TEGRA30_MC_DISPLAY0B		3
+#define TEGRA30_MC_DISPLAY0BB		4
+#define TEGRA30_MC_DISPLAY0C		5
+#define TEGRA30_MC_DISPLAY0CB		6
+#define TEGRA30_MC_DISPLAY1B		7
+#define TEGRA30_MC_DISPLAY1BB		8
+#define TEGRA30_MC_EPPUP		9
+#define TEGRA30_MC_G2PR			10
+#define TEGRA30_MC_G2SR			11
+#define TEGRA30_MC_MPEUNIFBR		12
+#define TEGRA30_MC_VIRUV		13
+#define TEGRA30_MC_AFIR			14
+#define TEGRA30_MC_AVPCARM7R		15
+#define TEGRA30_MC_DISPLAYHC		16
+#define TEGRA30_MC_DISPLAYHCB		17
+#define TEGRA30_MC_FDCDRD		18
+#define TEGRA30_MC_FDCDRD2		19
+#define TEGRA30_MC_G2DR			20
+#define TEGRA30_MC_HDAR			21
+#define TEGRA30_MC_HOST1XDMAR		22
+#define TEGRA30_MC_HOST1XR		23
+#define TEGRA30_MC_IDXSRD		24
+#define TEGRA30_MC_IDXSRD2		25
+#define TEGRA30_MC_MPE_IPRED		26
+#define TEGRA30_MC_MPEAMEMRD		27
+#define TEGRA30_MC_MPECSRD		28
+#define TEGRA30_MC_PPCSAHBDMAR		29
+#define TEGRA30_MC_PPCSAHBSLVR		30
+#define TEGRA30_MC_SATAR		31
+#define TEGRA30_MC_TEXSRD		32
+#define TEGRA30_MC_TEXSRD2		33
+#define TEGRA30_MC_VDEBSEVR		34
+#define TEGRA30_MC_VDEMBER		35
+#define TEGRA30_MC_VDEMCER		36
+#define TEGRA30_MC_VDETPER		37
+#define TEGRA30_MC_MPCORELPR		38
+#define TEGRA30_MC_MPCORER		39
+#define TEGRA30_MC_EPPU			40
+#define TEGRA30_MC_EPPV			41
+#define TEGRA30_MC_EPPY			42
+#define TEGRA30_MC_MPEUNIFBW		43
+#define TEGRA30_MC_VIWSB		44
+#define TEGRA30_MC_VIWU			45
+#define TEGRA30_MC_VIWV			46
+#define TEGRA30_MC_VIWY			47
+#define TEGRA30_MC_G2DW			48
+#define TEGRA30_MC_AFIW			49
+#define TEGRA30_MC_AVPCARM7W		50
+#define TEGRA30_MC_FDCDWR		51
+#define TEGRA30_MC_FDCDWR2		52
+#define TEGRA30_MC_HDAW			53
+#define TEGRA30_MC_HOST1XW		54
+#define TEGRA30_MC_ISPW			55
+#define TEGRA30_MC_MPCORELPW		56
+#define TEGRA30_MC_MPCOREW		57
+#define TEGRA30_MC_MPECSWR		58
+#define TEGRA30_MC_PPCSAHBDMAW		59
+#define TEGRA30_MC_PPCSAHBSLVW		60
+#define TEGRA30_MC_SATAW		61
+#define TEGRA30_MC_VDEBSEVW		62
+#define TEGRA30_MC_VDEDBGW		63
+#define TEGRA30_MC_VDEMBEW		64
+#define TEGRA30_MC_VDETPMW		65
+
 #endif
-- 
2.27.0

[PATCH v5 25/36] ARM: tegra: Add interconnect properties to Tegra20 device-tree

[Dmitry Osipenko]

Add interconnect properties to the memory controller, external memory
controller and the display controller nodes in order to describe hardware
interconnection.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra20.dtsi | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
index 72a4211a618f..629ad101c43b 100644
--- a/arch/arm/boot/dts/tegra20.dtsi
+++ b/arch/arm/boot/dts/tegra20.dtsi
@@ -111,6 +111,15 @@ dc@54200000 {
 
 			nvidia,head = <0>;
 
+			interconnects = <&mc TEGRA20_MC_DISPLAY0A &emc>,
+					<&mc TEGRA20_MC_DISPLAY0B &emc>,
+					<&mc TEGRA20_MC_DISPLAY0C &emc>,
+					<&mc TEGRA20_MC_DISPLAY1B &emc>;
+			interconnect-names = "wina",
+					     "winb",
+					     "winc",
+					     "cursor";
+
 			rgb {
 				status = "disabled";
 			};
@@ -128,6 +137,15 @@ dc@54240000 {
 
 			nvidia,head = <1>;
 
+			interconnects = <&mc TEGRA20_MC_DISPLAY0AB &emc>,
+					<&mc TEGRA20_MC_DISPLAY0BB &emc>,
+					<&mc TEGRA20_MC_DISPLAY0CB &emc>,
+					<&mc TEGRA20_MC_DISPLAY1BB &emc>;
+			interconnect-names = "wina",
+					     "winb",
+					     "winc",
+					     "cursor";
+
 			rgb {
 				status = "disabled";
 			};
@@ -630,15 +648,17 @@ mc: memory-controller@7000f000 {
 		interrupts = <GIC_SPI 77 IRQ_TYPE_LEVEL_HIGH>;
 		#reset-cells = <1>;
 		#iommu-cells = <0>;
+		#interconnect-cells = <1>;
 	};
 
-	memory-controller@7000f400 {
+	emc: memory-controller@7000f400 {
 		compatible = "nvidia,tegra20-emc";
 		reg = <0x7000f400 0x200>;
 		interrupts = <GIC_SPI 78 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&tegra_car TEGRA20_CLK_EMC>;
 		#address-cells = <1>;
 		#size-cells = <0>;
+		#interconnect-cells = <0>;
 	};
 
 	fuse@7000f800 {
-- 
2.27.0

[PATCH v5 26/36] ARM: tegra: Add interconnect properties to Tegra30 device-tree

[Dmitry Osipenko]

Add interconnect properties to the memory controller, external memory
controller and the display controller nodes in order to describe hardware
interconnection.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra30.dtsi | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/tegra30.dtsi b/arch/arm/boot/dts/tegra30.dtsi
index aeae8c092d41..b28360d3c039 100644
--- a/arch/arm/boot/dts/tegra30.dtsi
+++ b/arch/arm/boot/dts/tegra30.dtsi
@@ -210,6 +210,15 @@ dc@54200000 {
 
 			nvidia,head = <0>;
 
+			interconnects = <&mc TEGRA30_MC_DISPLAY0A &emc>,
+					<&mc TEGRA30_MC_DISPLAY0B &emc>,
+					<&mc TEGRA30_MC_DISPLAY0C &emc>,
+					<&mc TEGRA30_MC_DISPLAY1B &emc>;
+			interconnect-names = "wina",
+					     "winb",
+					     "winc",
+					     "cursor";
+
 			rgb {
 				status = "disabled";
 			};
@@ -229,6 +238,15 @@ dc@54240000 {
 
 			nvidia,head = <1>;
 
+			interconnects = <&mc TEGRA30_MC_DISPLAY0AB &emc>,
+					<&mc TEGRA30_MC_DISPLAY0BB &emc>,
+					<&mc TEGRA30_MC_DISPLAY0CB &emc>,
+					<&mc TEGRA30_MC_DISPLAY1BB &emc>;
+			interconnect-names = "wina",
+					     "winb",
+					     "winc",
+					     "cursor";
+
 			rgb {
 				status = "disabled";
 			};
@@ -748,15 +766,18 @@ mc: memory-controller@7000f000 {
 
 		#iommu-cells = <1>;
 		#reset-cells = <1>;
+		#interconnect-cells = <1>;
 	};
 
-	memory-controller@7000f400 {
+	emc: memory-controller@7000f400 {
 		compatible = "nvidia,tegra30-emc";
 		reg = <0x7000f400 0x400>;
 		interrupts = <GIC_SPI 78 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&tegra_car TEGRA30_CLK_EMC>;
 
 		nvidia,memory-controller = <&mc>;
+
+		#interconnect-cells = <0>;
 	};
 
 	fuse@7000f800 {
-- 
2.27.0

[PATCH v5 27/36] memory: tegra-mc: Register as interconnect provider

[Dmitry Osipenko]

Now memory controller is a memory interconnection provider. This allows us
to use interconnect API in order to change memory configuration.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/Kconfig |   1 +
 drivers/memory/tegra/mc.c    | 118 +++++++++++++++++++++++++++++++++++
 drivers/memory/tegra/mc.h    |   8 +++
 include/soc/tegra/mc.h       |   3 +
 4 files changed, 130 insertions(+)

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index 5bf75b316a2f..7055fdef2c32 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -3,6 +3,7 @@ config TEGRA_MC
 	bool "NVIDIA Tegra Memory Controller support"
 	default y
 	depends on ARCH_TEGRA
+	select INTERCONNECT
 	help
 	  This driver supports the Memory Controller (MC) hardware found on
 	  NVIDIA Tegra SoCs.
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 772aa021b5f6..46759ddaa3c9 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -594,6 +594,122 @@ static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static int tegra_mc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+	/*
+	 * The plan is to populate this function with a latency allowness
+	 * programming sometime later, for now this a dummy callback.
+	 */
+	return 0;
+}
+
+static int tegra_mc_icc_aggregate(struct icc_node *node,
+				  u32 tag, u32 avg_bw, u32 peak_bw,
+				  u32 *agg_avg, u32 *agg_peak)
+{
+	*agg_avg = min((u64)avg_bw + (*agg_avg), (u64)U32_MAX);
+	*agg_peak = max(*agg_peak, peak_bw);
+
+	return 0;
+}
+
+/*
+ * Memory Controller (MC) has few Memory Clients that are issuing memory
+ * bandwidth allocation requests to the MC interconnect provider. The MC
+ * provider aggregates the requests and then sends the aggregated request
+ * up to the External Memory Controller (EMC) interconnect provider which
+ * re-configures hardware interface to External Memory (EMEM) in accordance
+ * to the required bandwidth. Each MC interconnect node represents an
+ * individual Memory Client.
+ *
+ * Memory interconnect topology:
+ *
+ *               +----+
+ * +--------+    |    |
+ * | TEXSRD +--->+    |
+ * +--------+    |    |
+ *               |    |    +-----+    +------+
+ *    ...        | MC +--->+ EMC +--->+ EMEM |
+ *               |    |    +-----+    +------+
+ * +--------+    |    |
+ * | DISP.. +--->+    |
+ * +--------+    |    |
+ *               +----+
+ */
+static int tegra_mc_interconnect_setup(struct tegra_mc *mc)
+{
+	struct icc_onecell_data *data;
+	struct icc_node *node;
+	unsigned int num_nodes;
+	unsigned int i;
+	int err;
+
+	/* older device-trees don't have interconnect properties */
+	if (!of_find_property(mc->dev->of_node, "#interconnect-cells", NULL))
+		return 0;
+
+	num_nodes = mc->soc->num_clients;
+
+	data = devm_kzalloc(mc->dev, struct_size(data, nodes, num_nodes),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	mc->provider.dev = mc->dev;
+	mc->provider.set = tegra_mc_icc_set;
+	mc->provider.data = data;
+	mc->provider.xlate = of_icc_xlate_onecell;
+	mc->provider.aggregate = tegra_mc_icc_aggregate;
+
+	err = icc_provider_add(&mc->provider);
+	if (err)
+		goto err_msg;
+
+	/* create Memory Controller node */
+	node = icc_node_create(TEGRA_ICC_MC);
+	err = PTR_ERR_OR_ZERO(node);
+	if (err)
+		goto del_provider;
+
+	node->name = "Memory Controller";
+	icc_node_add(node, &mc->provider);
+
+	/* link Memory Controller to External Memory Controller */
+	err = icc_link_create(node, TEGRA_ICC_EMC);
+	if (err)
+		goto remove_nodes;
+
+	for (i = 0; i < num_nodes; i++) {
+		/* create MC client node */
+		node = icc_node_create(mc->soc->clients[i].id);
+		err = PTR_ERR_OR_ZERO(node);
+		if (err)
+			goto remove_nodes;
+
+		node->name = mc->soc->clients[i].name;
+		icc_node_add(node, &mc->provider);
+
+		/* link Memory Client to Memory Controller */
+		err = icc_link_create(node, TEGRA_ICC_MC);
+		if (err)
+			goto remove_nodes;
+
+		data->nodes[i] = node;
+	}
+	data->num_nodes = num_nodes;
+
+	return 0;
+
+remove_nodes:
+	icc_nodes_remove(&mc->provider);
+del_provider:
+	icc_provider_del(&mc->provider);
+err_msg:
+	dev_err(mc->dev, "failed to initialize ICC: %d\n", err);
+
+	return err;
+}
+
 static int tegra_mc_probe(struct platform_device *pdev)
 {
 	struct resource *res;
@@ -702,6 +818,8 @@ static int tegra_mc_probe(struct platform_device *pdev)
 		}
 	}
 
+	tegra_mc_interconnect_setup(mc);
+
 	return 0;
 }
 
diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h
index afa3ba45c9e6..abeb6a2cc36a 100644
--- a/drivers/memory/tegra/mc.h
+++ b/drivers/memory/tegra/mc.h
@@ -115,4 +115,12 @@ extern const struct tegra_mc_soc tegra132_mc_soc;
 extern const struct tegra_mc_soc tegra210_mc_soc;
 #endif
 
+/*
+ * These IDs are for internal use of Tegra's ICC, the values are chosen
+ * such that they don't conflict with the device-tree ICC node IDs.
+ */
+#define TEGRA_ICC_EMC		1000
+#define TEGRA_ICC_EMEM		2000
+#define TEGRA_ICC_MC		3000
+
 #endif /* MEMORY_TEGRA_MC_H */
diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h
index 1238e35653d1..71de023f9f47 100644
--- a/include/soc/tegra/mc.h
+++ b/include/soc/tegra/mc.h
@@ -7,6 +7,7 @@
 #define __SOC_TEGRA_MC_H__
 
 #include <linux/err.h>
+#include <linux/interconnect-provider.h>
 #include <linux/reset-controller.h>
 #include <linux/types.h>
 
@@ -178,6 +179,8 @@ struct tegra_mc {
 
 	struct reset_controller_dev reset;
 
+	struct icc_provider provider;
+
 	spinlock_t lock;
 };
 
-- 
2.27.0

Re: [PATCH v5 27/36] memory: tegra-mc: Register as interconnect provider

[Georgi Djakov]

On 8/14/20 03:06, Dmitry Osipenko wrote:
> Now memory controller is a memory interconnection provider. This allows us
> to use interconnect API in order to change memory configuration.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Thanks Dmitry! Looks good to me.

Acked-by: Georgi Djakov <georgi.djakov@linaro.org>

Re: [PATCH v5 27/36] memory: tegra-mc: Register as interconnect provider

[Dmitry Osipenko]

09.09.2020 11:31, Georgi Djakov пишет:
> On 8/14/20 03:06, Dmitry Osipenko wrote:
>> Now memory controller is a memory interconnection provider. This allows us
>> to use interconnect API in order to change memory configuration.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> 
> Thanks Dmitry! Looks good to me.
> 
> Acked-by: Georgi Djakov <georgi.djakov@linaro.org>
> 

Thanks you!

[PATCH v5 28/36] memory: tegra20-emc: Use devm_platform_ioremap_resource

[Dmitry Osipenko]

Utilize that relatively new helper which makes code a bit cleaner.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/tegra20-emc.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index a02ffc09c39e..db6a4bcb92fb 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -696,7 +696,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
 {
 	struct device_node *np;
 	struct tegra_emc *emc;
-	struct resource *res;
 	int irq, err;
 
 	/* driver has nothing to do in a case of memory timing absence */
@@ -731,8 +730,7 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	emc->regs = devm_ioremap_resource(&pdev->dev, res);
+	emc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(emc->regs))
 		return PTR_ERR(emc->regs);
 
-- 
2.27.0

[PATCH v5 29/36] memory: tegra20-emc: Continue probing if timings are missing in device-tree

[Dmitry Osipenko]

EMC driver will become mandatory after turning it into interconnect
provider because interconnect users, like display controller driver, will
fail to probe using newer device-trees that have interconnect properties.
Thus make EMC driver to probe even if timings are missing in device-tree.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/tegra20-emc.c | 34 ++++++++++++++----------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index db6a4bcb92fb..89e077d797e7 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -386,6 +386,11 @@ tegra_emc_find_node_by_ram_code(struct device *dev)
 	u32 value, ram_code;
 	int err;
 
+	if (of_get_child_count(dev->of_node) == 0) {
+		dev_info(dev, "device-tree doesn't have memory timings\n");
+		return NULL;
+	}
+
 	if (!of_property_read_bool(dev->of_node, "nvidia,use-ram-code"))
 		return of_node_get(dev->of_node);
 
@@ -454,6 +459,9 @@ static long emc_round_rate(unsigned long rate,
 	struct tegra_emc *emc = arg;
 	unsigned int i;
 
+	if (!emc->num_timings)
+		return clk_get_rate(emc->clk);
+
 	min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);
 
 	for (i = 0; i < emc->num_timings; i++) {
@@ -698,13 +706,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	struct tegra_emc *emc;
 	int irq, err;
 
-	/* driver has nothing to do in a case of memory timing absence */
-	if (of_get_child_count(pdev->dev.of_node) == 0) {
-		dev_info(&pdev->dev,
-			 "EMC device tree node doesn't have memory timings\n");
-		return 0;
-	}
-
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "interrupt not specified\n");
@@ -712,23 +713,20 @@ static int tegra_emc_probe(struct platform_device *pdev)
 		return irq;
 	}
 
-	np = tegra_emc_find_node_by_ram_code(&pdev->dev);
-	if (!np)
-		return -EINVAL;
-
 	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
-	if (!emc) {
-		of_node_put(np);
+	if (!emc)
 		return -ENOMEM;
-	}
 
 	emc->clk_nb.notifier_call = tegra_emc_clk_change_notify;
 	emc->dev = &pdev->dev;
 
-	err = tegra_emc_load_timings_from_dt(emc, np);
-	of_node_put(np);
-	if (err)
-		return err;
+	np = tegra_emc_find_node_by_ram_code(&pdev->dev);
+	if (np) {
+		err = tegra_emc_load_timings_from_dt(emc, np);
+		of_node_put(np);
+		if (err)
+			return err;
+	}
 
 	emc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(emc->regs))
-- 
2.27.0

[PATCH v5 30/36] memory: tegra20-emc: Register as interconnect provider

[Dmitry Osipenko]

Now memory controller is a memory interconnection provider. This allows us
to use interconnect API in order to change memory configuration.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/tegra20-emc.c | 110 +++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index 89e077d797e7..437d9d789941 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -9,6 +9,7 @@
 #include <linux/clk/tegra.h>
 #include <linux/debugfs.h>
 #include <linux/err.h>
+#include <linux/interconnect-provider.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -148,6 +149,7 @@ struct emc_timing {
 struct tegra_emc {
 	struct device *dev;
 	struct notifier_block clk_nb;
+	struct icc_provider provider;
 	struct clk *clk;
 	void __iomem *regs;
 
@@ -661,6 +663,113 @@ static void tegra_emc_debugfs_init(struct tegra_emc *emc)
 			    emc, &tegra_emc_debug_max_rate_fops);
 }
 
+static inline struct tegra_emc *
+to_tegra_emc_provider(struct icc_provider *provider)
+{
+	return container_of(provider, struct tegra_emc, provider);
+}
+
+static struct icc_node *
+emc_of_icc_xlate(struct of_phandle_args *spec, void *data)
+{
+	struct icc_provider *provider = data;
+	struct icc_node *node;
+
+	/* External Memory is the only possible ICC route */
+	list_for_each_entry(node, &provider->nodes, node_list) {
+		if (node->id == TEGRA_ICC_EMEM)
+			return node;
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+	struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
+	unsigned long long rate = icc_units_to_bps(dst->avg_bw);
+	unsigned int dram_data_bus_width_bytes = 4;
+	unsigned int ddr = 2;
+	int err;
+
+	do_div(rate, ddr * dram_data_bus_width_bytes);
+	rate = min_t(u64, rate, U32_MAX);
+
+	err = clk_set_min_rate(emc->clk, rate);
+	if (err)
+		return err;
+
+	err = clk_set_rate(emc->clk, rate);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int emc_icc_aggregate(struct icc_node *node,
+			     u32 tag, u32 avg_bw, u32 peak_bw,
+			     u32 *agg_avg, u32 *agg_peak)
+{
+	*agg_avg = min((u64)avg_bw + (*agg_avg), (u64)U32_MAX);
+	*agg_peak = max(*agg_peak, peak_bw);
+
+	return 0;
+}
+
+static int tegra_emc_interconnect_init(struct tegra_emc *emc)
+{
+	struct icc_node *node;
+	int err;
+
+	/* older device-trees don't have interconnect properties */
+	if (!of_find_property(emc->dev->of_node, "#interconnect-cells", NULL))
+		return 0;
+
+	emc->provider.dev = emc->dev;
+	emc->provider.set = emc_icc_set;
+	emc->provider.data = &emc->provider;
+	emc->provider.xlate = emc_of_icc_xlate;
+	emc->provider.aggregate = emc_icc_aggregate;
+
+	err = icc_provider_add(&emc->provider);
+	if (err)
+		goto err_msg;
+
+	/* create External Memory Controller node */
+	node = icc_node_create(TEGRA_ICC_EMC);
+	err = PTR_ERR_OR_ZERO(node);
+	if (err)
+		goto del_provider;
+
+	node->name = "External Memory Controller";
+	icc_node_add(node, &emc->provider);
+
+	/* link External Memory Controller to External Memory (DRAM) */
+	err = icc_link_create(node, TEGRA_ICC_EMEM);
+	if (err)
+		goto remove_nodes;
+
+	/* create External Memory node */
+	node = icc_node_create(TEGRA_ICC_EMEM);
+	err = PTR_ERR_OR_ZERO(node);
+	if (err)
+		goto remove_nodes;
+
+	node->name = "External Memory (DRAM)";
+	icc_node_add(node, &emc->provider);
+
+	return 0;
+
+remove_nodes:
+	icc_nodes_remove(&emc->provider);
+del_provider:
+	icc_provider_del(&emc->provider);
+err_msg:
+	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
+
+	return err;
+}
+
 static int tegra_emc_init_mc_timings(struct tegra_emc *emc)
 {
 	struct tegra_mc_timing *timing;
@@ -773,6 +882,7 @@ static int tegra_emc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, emc);
 	tegra_emc_debugfs_init(emc);
+	tegra_emc_interconnect_init(emc);
 
 	/*
 	 * Don't allow the kernel module to be unloaded. Unloading adds some
-- 
2.27.0

Re: [PATCH v5 30/36] memory: tegra20-emc: Register as interconnect provider

[Georgi Djakov]

On 8/14/20 03:06, Dmitry Osipenko wrote:
> Now memory controller is a memory interconnection provider. This allows us
> to use interconnect API in order to change memory configuration.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Acked-by: Georgi Djakov <georgi.djakov@linaro.org>

[PATCH v5 31/36] memory: tegra20-emc: Create tegra20-devfreq device

[Dmitry Osipenko]

The tegra20-devfreq driver provides memory frequency scaling functionality
and it uses EMC clock for the scaling. Since tegra20-devfreq is a software
driver, the device for the driver needs to be created manually. Let's do
it from EMC driver since it provides the clk rate-change functionality.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/tegra20-emc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index 437d9d789941..e603cc0b0341 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -884,6 +884,9 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	tegra_emc_debugfs_init(emc);
 	tegra_emc_interconnect_init(emc);
 
+	if (IS_ENABLED(CONFIG_ARM_TEGRA20_DEVFREQ))
+		platform_device_register_simple("tegra20-devfreq", -1, NULL, 0);
+
 	/*
 	 * Don't allow the kernel module to be unloaded. Unloading adds some
 	 * extra complexity which doesn't really worth the effort in a case of
-- 
2.27.0

[PATCH v5 32/36] memory: tegra30-emc: Continue probing if timings are missing in device-tree

[Dmitry Osipenko]

EMC driver will become mandatory after turning it into interconnect
provider because interconnect users, like display controller driver, will
fail to probe using newer device-trees that have interconnect properties.
Thus make EMC driver to probe even if timings are missing in device-tree.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/tegra30-emc.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index f3082964cfb6..0cd39bf5f393 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -988,6 +988,11 @@ static struct device_node *emc_find_node_by_ram_code(struct device *dev)
 	u32 value, ram_code;
 	int err;
 
+	if (of_get_child_count(dev->of_node) == 0) {
+		dev_info(dev, "device-tree doesn't have memory timings\n");
+		return NULL;
+	}
+
 	ram_code = tegra_read_ram_code();
 
 	for_each_child_of_node(dev->of_node, np) {
@@ -1057,6 +1062,9 @@ static long emc_round_rate(unsigned long rate,
 	struct tegra_emc *emc = arg;
 	unsigned int i;
 
+	if (!emc->num_timings)
+		return clk_get_rate(emc->clk);
+
 	min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);
 
 	for (i = 0; i < emc->num_timings; i++) {
@@ -1263,12 +1271,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	struct tegra_emc *emc;
 	int err;
 
-	if (of_get_child_count(pdev->dev.of_node) == 0) {
-		dev_info(&pdev->dev,
-			 "device-tree node doesn't have memory timings\n");
-		return -ENODEV;
-	}
-
 	np = of_parse_phandle(pdev->dev.of_node, "nvidia,memory-controller", 0);
 	if (!np) {
 		dev_err(&pdev->dev, "could not get memory controller node\n");
@@ -1280,10 +1282,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	if (!mc)
 		return -ENOENT;
 
-	np = emc_find_node_by_ram_code(&pdev->dev);
-	if (!np)
-		return -EINVAL;
-
 	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
 	if (!emc) {
 		of_node_put(np);
@@ -1297,10 +1295,13 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	emc->clk_nb.notifier_call = emc_clk_change_notify;
 	emc->dev = &pdev->dev;
 
-	err = emc_load_timings_from_dt(emc, np);
-	of_node_put(np);
-	if (err)
-		return err;
+	np = emc_find_node_by_ram_code(&pdev->dev);
+	if (np) {
+		err = emc_load_timings_from_dt(emc, np);
+		of_node_put(np);
+		if (err)
+			return err;
+	}
 
 	emc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(emc->regs))
-- 
2.27.0

[PATCH v5 33/36] memory: tegra30-emc: Register as interconnect provider

[Dmitry Osipenko]

Now external memory controller is a memory interconnection provider.
This allows us to use interconnect API to change memory configuration.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/memory/tegra/tegra30-emc.c | 110 +++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index 0cd39bf5f393..29448d02f750 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -14,6 +14,7 @@
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <linux/interconnect-provider.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -327,6 +328,7 @@ struct tegra_emc {
 	struct device *dev;
 	struct tegra_mc *mc;
 	struct notifier_block clk_nb;
+	struct icc_provider provider;
 	struct clk *clk;
 	void __iomem *regs;
 	unsigned int irq;
@@ -1264,6 +1266,113 @@ static void tegra_emc_debugfs_init(struct tegra_emc *emc)
 			    emc, &tegra_emc_debug_max_rate_fops);
 }
 
+static inline struct tegra_emc *
+to_tegra_emc_provider(struct icc_provider *provider)
+{
+	return container_of(provider, struct tegra_emc, provider);
+}
+
+static struct icc_node *
+emc_of_icc_xlate(struct of_phandle_args *spec, void *data)
+{
+	struct icc_provider *provider = data;
+	struct icc_node *node;
+
+	/* External Memory is the only possible ICC route */
+	list_for_each_entry(node, &provider->nodes, node_list) {
+		if (node->id == TEGRA_ICC_EMEM)
+			return node;
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+	struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
+	unsigned long long rate = icc_units_to_bps(dst->avg_bw);
+	unsigned int dram_data_bus_width_bytes = 4;
+	unsigned int ddr = 2;
+	int err;
+
+	do_div(rate, ddr * dram_data_bus_width_bytes);
+	rate = min_t(u64, rate, U32_MAX);
+
+	err = clk_set_min_rate(emc->clk, rate);
+	if (err)
+		return err;
+
+	err = clk_set_rate(emc->clk, rate);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int emc_icc_aggregate(struct icc_node *node,
+			     u32 tag, u32 avg_bw, u32 peak_bw,
+			     u32 *agg_avg, u32 *agg_peak)
+{
+	*agg_avg = min((u64)avg_bw + (*agg_avg), (u64)U32_MAX);
+	*agg_peak = max(*agg_peak, peak_bw);
+
+	return 0;
+}
+
+static int tegra_emc_interconnect_init(struct tegra_emc *emc)
+{
+	struct icc_node *node;
+	int err;
+
+	/* older device-trees don't have interconnect properties */
+	if (!of_find_property(emc->dev->of_node, "#interconnect-cells", NULL))
+		return 0;
+
+	emc->provider.dev = emc->dev;
+	emc->provider.set = emc_icc_set;
+	emc->provider.data = &emc->provider;
+	emc->provider.xlate = emc_of_icc_xlate;
+	emc->provider.aggregate = emc_icc_aggregate;
+
+	err = icc_provider_add(&emc->provider);
+	if (err)
+		goto err_msg;
+
+	/* create External Memory Controller node */
+	node = icc_node_create(TEGRA_ICC_EMC);
+	err = PTR_ERR_OR_ZERO(node);
+	if (err)
+		goto del_provider;
+
+	node->name = "External Memory Controller";
+	icc_node_add(node, &emc->provider);
+
+	/* link External Memory Controller to External Memory (DRAM) */
+	err = icc_link_create(node, TEGRA_ICC_EMEM);
+	if (err)
+		goto remove_nodes;
+
+	/* create External Memory node */
+	node = icc_node_create(TEGRA_ICC_EMEM);
+	err = PTR_ERR_OR_ZERO(node);
+	if (err)
+		goto remove_nodes;
+
+	node->name = "External Memory (DRAM)";
+	icc_node_add(node, &emc->provider);
+
+	return 0;
+
+remove_nodes:
+	icc_nodes_remove(&emc->provider);
+del_provider:
+	icc_provider_del(&emc->provider);
+err_msg:
+	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
+
+	return err;
+}
+
 static int tegra_emc_probe(struct platform_device *pdev)
 {
 	struct platform_device *mc;
@@ -1343,6 +1452,7 @@ static int tegra_emc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, emc);
 	tegra_emc_debugfs_init(emc);
+	tegra_emc_interconnect_init(emc);
 
 	/*
 	 * Don't allow the kernel module to be unloaded. Unloading adds some
-- 
2.27.0

Re: [PATCH v5 33/36] memory: tegra30-emc: Register as interconnect provider

[Georgi Djakov]

On 8/14/20 03:06, Dmitry Osipenko wrote:
> Now external memory controller is a memory interconnection provider.
> This allows us to use interconnect API to change memory configuration.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Acked-by: Georgi Djakov <georgi.djakov@linaro.org>

[PATCH v5 34/36] drm/tegra: dc: Support memory bandwidth management

[Dmitry Osipenko]

Display controller (DC) performs isochronous memory transfers, and thus,
has a requirement for a minimum memory bandwidth that shall be fulfilled,
otherwise framebuffer data can't be fetched fast enough and this results
in a DC's data-FIFO underflow that follows by a visual corruption.

The Memory Controller drivers provide facility for memory bandwidth
management via interconnect API. This patch wires up the interconnect
API support to the DC driver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/gpu/drm/tegra/Kconfig |   1 +
 drivers/gpu/drm/tegra/dc.c    | 271 +++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/tegra/dc.h    |   8 +
 drivers/gpu/drm/tegra/drm.c   |  19 +++
 drivers/gpu/drm/tegra/plane.c |   1 +
 drivers/gpu/drm/tegra/plane.h |   4 +-
 6 files changed, 300 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/tegra/Kconfig b/drivers/gpu/drm/tegra/Kconfig
index 5043dcaf1cf9..1650a448eabd 100644
--- a/drivers/gpu/drm/tegra/Kconfig
+++ b/drivers/gpu/drm/tegra/Kconfig
@@ -9,6 +9,7 @@ config DRM_TEGRA
 	select DRM_MIPI_DSI
 	select DRM_PANEL
 	select TEGRA_HOST1X
+	select INTERCONNECT
 	select IOMMU_IOVA
 	select CEC_CORE if CEC_NOTIFIER
 	help
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 9a0b3240bc58..850fbcebefc2 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -525,6 +525,136 @@ static void tegra_dc_setup_window(struct tegra_plane *plane,
 		tegra_plane_setup_blending(plane, window);
 }
 
+static unsigned long
+tegra_plane_memory_bandwidth(struct drm_plane_state *state,
+			     struct tegra_dc_window *window,
+			     unsigned int num,
+			     unsigned int denum)
+{
+	struct tegra_plane_state *tegra_state;
+	struct drm_crtc_state *crtc_state;
+	const struct drm_format_info *fmt;
+	struct tegra_dc_window win;
+	unsigned long long bandwidth;
+	unsigned int bpp_plane;
+	unsigned int bpp;
+	unsigned int mul;
+	unsigned int i;
+
+	if (!state->fb || !state->visible)
+		return 0;
+
+	crtc_state = drm_atomic_get_new_crtc_state(state->state, state->crtc);
+	tegra_state = to_tegra_plane_state(state);
+
+	if (!window)
+		window = &win;
+
+	window->src.w = drm_rect_width(&state->src) >> 16;
+	window->src.h = drm_rect_height(&state->src) >> 16;
+	window->dst.w = drm_rect_width(&state->dst);
+	window->dst.h = drm_rect_height(&state->dst);
+	window->tiling = tegra_state->tiling;
+
+	fmt = state->fb->format;
+
+	/*
+	 * Note that real memory bandwidth vary depending on format and
+	 * memory layout, we are not taking that into account because small
+	 * estimation error isn't important since bandwidth is rounded up
+	 * anyway.
+	 */
+	for (i = 0, bpp = 0; i < fmt->num_planes; i++) {
+		bpp_plane = fmt->cpp[i] * 8;
+
+		/*
+		 * Sub-sampling is relevant for chroma planes only and vertical
+		 * readouts are not cached, hence only horizontal sub-sampling
+		 * matters.
+		 */
+		if (i > 0)
+			bpp_plane /= fmt->hsub;
+
+		bpp += bpp_plane;
+	}
+
+	/*
+	 * Horizontal downscale takes extra bandwidth which roughly depends
+	 * on the scaled width.
+	 */
+	if (window->src.w > window->dst.w)
+		mul = (window->src.w - window->dst.w) * bpp / 2048 + 1;
+	else
+		mul = 1;
+
+	/*
+	 * Ignore cursor window if its width is small enough such that
+	 * data-prefetch FIFO will easily help to overcome temporal memory
+	 * pressure.
+	 *
+	 * Window A has a 128bit x 128 deep read FIFO, while windows B/C
+	 * have a 128bit x 64 deep read FIFO.
+	 *
+	 * This allows us to not overestimate memory frequency requirement.
+	 * Even if it will happen that cursor gets a temporal underflow, this
+	 * won't be fatal.
+	 */
+	if (state->plane->type == DRM_PLANE_TYPE_CURSOR &&
+	    mul == 1 && window->src.w * bpp <= 128 * 16)
+		return 0;
+
+	/* mode.clock in kHz, bandwidth in kbit/s */
+	bandwidth = kbps_to_icc(crtc_state->mode.clock * bpp * mul);
+
+	/* the requested bandwidth should be higher than required */
+	bandwidth *= num;
+	do_div(bandwidth, denum);
+
+	return min_t(u64, bandwidth, ULONG_MAX);
+}
+
+static unsigned long
+tegra20_plane_memory_bandwidth(struct drm_plane_state *state)
+{
+	return tegra_plane_memory_bandwidth(state, NULL, 29, 10);
+}
+
+static unsigned long
+tegra30_plane_memory_bandwidth(struct drm_plane_state *state)
+{
+	struct tegra_dc_window window;
+	unsigned long bandwidth;
+
+	bandwidth = tegra_plane_memory_bandwidth(state, &window, 29, 10);
+
+	/* x2: memory overfetch for tiled framebuffer and DDR3 */
+	if (window.tiling.mode == TEGRA_BO_TILING_MODE_TILED)
+		bandwidth *= 2;
+
+	return bandwidth;
+}
+
+static unsigned long
+tegra114_plane_memory_bandwidth(struct drm_plane_state *state)
+{
+	struct tegra_dc_window window;
+	unsigned long bandwidth;
+
+	bandwidth = tegra_plane_memory_bandwidth(state, &window, 12, 10);
+
+	/* x2: memory overfetch for tiled framebuffer and DDR3 */
+	if (window.tiling.mode == TEGRA_BO_TILING_MODE_TILED)
+		bandwidth *= 2;
+
+	return bandwidth;
+}
+
+static unsigned long
+tegra124_plane_memory_bandwidth(struct drm_plane_state *state)
+{
+	return tegra_plane_memory_bandwidth(state, NULL, 12, 10);
+}
+
 static const u32 tegra20_primary_formats[] = {
 	DRM_FORMAT_ARGB4444,
 	DRM_FORMAT_ARGB1555,
@@ -617,8 +747,10 @@ static int tegra_plane_atomic_check(struct drm_plane *plane,
 	int err;
 
 	/* no need for further checks if the plane is being disabled */
-	if (!state->crtc)
+	if (!state->crtc) {
+		plane_state->memory_bandwidth = 0;
 		return 0;
+	}
 
 	err = tegra_plane_format(state->fb->format->format,
 				 &plane_state->format,
@@ -685,6 +817,8 @@ static int tegra_plane_atomic_check(struct drm_plane *plane,
 	if (err < 0)
 		return err;
 
+	plane_state->memory_bandwidth = dc->soc->plane_memory_bandwidth(state);
+
 	return 0;
 }
 
@@ -1214,6 +1348,7 @@ tegra_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
 	copy->pclk = state->pclk;
 	copy->div = state->div;
 	copy->planes = state->planes;
+	copy->memory_bandwidth = state->memory_bandwidth;
 
 	return &copy->base;
 }
@@ -1796,6 +1931,8 @@ static void tegra_crtc_atomic_disable(struct drm_crtc *crtc,
 	err = host1x_client_suspend(&dc->client);
 	if (err < 0)
 		dev_err(dc->dev, "failed to suspend: %d\n", err);
+
+	icc_set_bw(dc->icc_bandwidth, 0, 0);
 }
 
 static void tegra_crtc_atomic_enable(struct drm_crtc *crtc,
@@ -1807,6 +1944,9 @@ static void tegra_crtc_atomic_enable(struct drm_crtc *crtc,
 	u32 value;
 	int err;
 
+	icc_set_bw(dc->icc_bandwidth, state->memory_bandwidth,
+		   state->memory_bandwidth);
+
 	err = host1x_client_resume(&dc->client);
 	if (err < 0) {
 		dev_err(dc->dev, "failed to resume: %d\n", err);
@@ -1920,6 +2060,9 @@ static void tegra_crtc_atomic_enable(struct drm_crtc *crtc,
 static void tegra_crtc_atomic_begin(struct drm_crtc *crtc,
 				    struct drm_crtc_state *old_crtc_state)
 {
+	struct tegra_dc_state *dc_old_state = to_dc_state(old_crtc_state);
+	struct tegra_dc_state *dc_state = to_dc_state(crtc->state);
+	struct tegra_dc *dc = to_tegra_dc(crtc);
 	unsigned long flags;
 
 	if (crtc->state->event) {
@@ -1934,6 +2077,25 @@ static void tegra_crtc_atomic_begin(struct drm_crtc *crtc,
 
 		crtc->state->event = NULL;
 	}
+
+	if (old_crtc_state && old_crtc_state->active) {
+		/*
+		 * Raise memory bandwidth before changes take effect if it
+		 * goes from low to high.
+		 */
+		if (dc_old_state->memory_bandwidth < dc_state->memory_bandwidth)
+			icc_set_bw(dc->icc_bandwidth,
+				   dc_state->memory_bandwidth,
+				   dc_state->memory_bandwidth);
+	} else {
+		/*
+		 * Raise memory bandwidth before changes take effect if
+		 * CRTC is turning on.
+		 */
+		icc_set_bw(dc->icc_bandwidth,
+			   dc_state->memory_bandwidth,
+			   dc_state->memory_bandwidth);
+	}
 }
 
 static void tegra_crtc_atomic_flush(struct drm_crtc *crtc,
@@ -1952,7 +2114,80 @@ static void tegra_crtc_atomic_flush(struct drm_crtc *crtc,
 	value = tegra_dc_readl(dc, DC_CMD_STATE_CONTROL);
 }
 
+static bool
+tegra_plane_overlaps_other_plane(struct drm_crtc_state *state,
+				 const struct drm_plane_state *plane_state)
+{
+	const struct drm_plane_state *other_state;
+	struct drm_plane *plane;
+	struct drm_rect rect;
+
+	drm_atomic_crtc_state_for_each_plane_state(plane, other_state, state) {
+		rect = plane_state->dst;
+
+		if (other_state == plane_state)
+			continue;
+
+		if (!other_state->visible || !other_state->fb)
+			continue;
+
+		if (drm_rect_intersect(&rect, &other_state->dst))
+			return true;
+	}
+
+	return false;
+}
+
+static int tegra_crtc_atomic_check(struct drm_crtc *crtc,
+				   struct drm_crtc_state *state)
+{
+	struct tegra_dc_state *dc_state = to_dc_state(state);
+	const struct drm_plane_state *plane_state;
+	const struct tegra_plane_state *tegra;
+	unsigned long long bandwidth = 0;
+	struct drm_plane *plane;
+
+	/*
+	 * For overlapping planes pixel's data is fetched for each plane at
+	 * the same time, hence bandwidth is accumulated in this case.
+	 */
+	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, state) {
+		tegra = to_tegra_plane_state(plane_state);
+
+		if (tegra_plane_overlaps_other_plane(state, plane_state))
+			bandwidth += tegra->memory_bandwidth;
+		else
+			bandwidth = max_t(u64, bandwidth,
+					  tegra->memory_bandwidth);
+	}
+
+	dc_state->memory_bandwidth = min_t(u64, bandwidth, U32_MAX);
+
+	return 0;
+}
+
+void tegra_crtc_atomic_post_commit(struct drm_crtc *crtc,
+				   struct drm_crtc_state *old_crtc_state)
+{
+	struct tegra_dc_state *dc_old_state = to_dc_state(old_crtc_state);
+	struct tegra_dc_state *dc_state = to_dc_state(crtc->state);
+	struct tegra_dc *dc = to_tegra_dc(crtc);
+
+	if (!dc_old_state)
+		return;
+
+	/*
+	 * Drop memory bandwidth after changes take effect if it goes from
+	 * high to low.
+	 */
+	if (dc_old_state->memory_bandwidth > dc_state->memory_bandwidth)
+		icc_set_bw(dc->icc_bandwidth,
+			   dc_state->memory_bandwidth,
+			   dc_state->memory_bandwidth);
+}
+
 static const struct drm_crtc_helper_funcs tegra_crtc_helper_funcs = {
+	.atomic_check = tegra_crtc_atomic_check,
 	.atomic_begin = tegra_crtc_atomic_begin,
 	.atomic_flush = tegra_crtc_atomic_flush,
 	.atomic_enable = tegra_crtc_atomic_enable,
@@ -2244,6 +2479,7 @@ static const struct tegra_dc_soc_info tegra20_dc_soc_info = {
 	.modifiers = tegra20_modifiers,
 	.has_win_a_without_filters = true,
 	.has_win_c_without_vert_filter = true,
+	.plane_memory_bandwidth = tegra20_plane_memory_bandwidth,
 };
 
 static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
@@ -2263,6 +2499,7 @@ static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
 	.modifiers = tegra20_modifiers,
 	.has_win_a_without_filters = false,
 	.has_win_c_without_vert_filter = false,
+	.plane_memory_bandwidth = tegra30_plane_memory_bandwidth,
 };
 
 static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
@@ -2282,6 +2519,7 @@ static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
 	.modifiers = tegra20_modifiers,
 	.has_win_a_without_filters = false,
 	.has_win_c_without_vert_filter = false,
+	.plane_memory_bandwidth = tegra114_plane_memory_bandwidth,
 };
 
 static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
@@ -2301,6 +2539,7 @@ static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
 	.modifiers = tegra124_modifiers,
 	.has_win_a_without_filters = false,
 	.has_win_c_without_vert_filter = false,
+	.plane_memory_bandwidth = tegra124_plane_memory_bandwidth,
 };
 
 static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
@@ -2320,6 +2559,7 @@ static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
 	.modifiers = tegra124_modifiers,
 	.has_win_a_without_filters = false,
 	.has_win_c_without_vert_filter = false,
+	.plane_memory_bandwidth = tegra124_plane_memory_bandwidth,
 };
 
 static const struct tegra_windowgroup_soc tegra186_dc_wgrps[] = {
@@ -2368,6 +2608,7 @@ static const struct tegra_dc_soc_info tegra186_dc_soc_info = {
 	.has_nvdisplay = true,
 	.wgrps = tegra186_dc_wgrps,
 	.num_wgrps = ARRAY_SIZE(tegra186_dc_wgrps),
+	.plane_memory_bandwidth = tegra124_plane_memory_bandwidth,
 };
 
 static const struct tegra_windowgroup_soc tegra194_dc_wgrps[] = {
@@ -2416,6 +2657,7 @@ static const struct tegra_dc_soc_info tegra194_dc_soc_info = {
 	.has_nvdisplay = true,
 	.wgrps = tegra194_dc_wgrps,
 	.num_wgrps = ARRAY_SIZE(tegra194_dc_wgrps),
+	.plane_memory_bandwidth = tegra124_plane_memory_bandwidth,
 };
 
 static const struct of_device_id tegra_dc_of_match[] = {
@@ -2522,6 +2764,7 @@ static int tegra_dc_couple(struct tegra_dc *dc)
 
 static int tegra_dc_probe(struct platform_device *pdev)
 {
+	const char *level = KERN_ERR;
 	struct tegra_dc *dc;
 	int err;
 
@@ -2588,8 +2831,6 @@ static int tegra_dc_probe(struct platform_device *pdev)
 
 	err = tegra_dc_rgb_probe(dc);
 	if (err < 0 && err != -ENODEV) {
-		const char *level = KERN_ERR;
-
 		if (err == -EPROBE_DEFER)
 			level = KERN_DEBUG;
 
@@ -2598,6 +2839,25 @@ static int tegra_dc_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	/*
+	 * The display controller memory bandwidth management isn't trivial
+	 * because it requires the knowledge about the DC hardware state
+	 * in order to make a proper decisions. It's not easy to convey
+	 * that information to the ICC provider, so we will just use the
+	 * first interconnect path for the memory bandwidth management and
+	 * make all the decisions within the DC driver, for simplicity.
+	 */
+	dc->icc_bandwidth = of_icc_get(dc->dev, "wina");
+	err = PTR_ERR_OR_ZERO(dc->icc_bandwidth);
+	if (err) {
+		if (err == -EPROBE_DEFER)
+			level = KERN_DEBUG;
+
+		dev_printk(level, dc->dev,
+			   "failed to get wina interconnect: %d\n", err);
+		goto remove_rgb;
+	}
+
 	platform_set_drvdata(pdev, dc);
 	pm_runtime_enable(&pdev->dev);
 
@@ -2616,6 +2876,9 @@ static int tegra_dc_probe(struct platform_device *pdev)
 
 disable_pm:
 	pm_runtime_disable(&pdev->dev);
+	icc_put(dc->icc_bandwidth);
+
+remove_rgb:
 	tegra_dc_rgb_remove(dc);
 
 	return err;
@@ -2633,6 +2896,8 @@ static int tegra_dc_remove(struct platform_device *pdev)
 		return err;
 	}
 
+	icc_put(dc->icc_bandwidth);
+
 	err = tegra_dc_rgb_remove(dc);
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed to remove RGB output: %d\n", err);
diff --git a/drivers/gpu/drm/tegra/dc.h b/drivers/gpu/drm/tegra/dc.h
index 051d03dcb9b0..b70eeeee2033 100644
--- a/drivers/gpu/drm/tegra/dc.h
+++ b/drivers/gpu/drm/tegra/dc.h
@@ -8,6 +8,7 @@
 #define TEGRA_DC_H 1
 
 #include <linux/host1x.h>
+#include <linux/interconnect.h>
 
 #include <drm/drm_crtc.h>
 
@@ -23,6 +24,8 @@ struct tegra_dc_state {
 	unsigned int div;
 
 	u32 planes;
+
+	unsigned long memory_bandwidth;
 };
 
 static inline struct tegra_dc_state *to_dc_state(struct drm_crtc_state *state)
@@ -66,6 +69,7 @@ struct tegra_dc_soc_info {
 	const u64 *modifiers;
 	bool has_win_a_without_filters;
 	bool has_win_c_without_vert_filter;
+	unsigned long (*plane_memory_bandwidth)(struct drm_plane_state *state);
 };
 
 struct tegra_dc {
@@ -90,6 +94,8 @@ struct tegra_dc {
 	struct drm_info_list *debugfs_files;
 
 	const struct tegra_dc_soc_info *soc;
+
+	struct icc_path *icc_bandwidth;
 };
 
 static inline struct tegra_dc *
@@ -151,6 +157,8 @@ int tegra_dc_state_setup_clock(struct tegra_dc *dc,
 			       struct drm_crtc_state *crtc_state,
 			       struct clk *clk, unsigned long pclk,
 			       unsigned int div);
+void tegra_crtc_atomic_post_commit(struct drm_crtc *crtc,
+				   struct drm_crtc_state *old_crtc_state);
 
 /* from rgb.c */
 int tegra_dc_rgb_probe(struct tegra_dc *dc);
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index ba9d1c3e7cac..f648adb22731 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -20,6 +20,7 @@
 #include <drm/drm_prime.h>
 #include <drm/drm_vblank.h>
 
+#include "dc.h"
 #include "drm.h"
 #include "gem.h"
 
@@ -59,6 +60,22 @@ static const struct drm_mode_config_funcs tegra_drm_mode_config_funcs = {
 	.atomic_commit = drm_atomic_helper_commit,
 };
 
+static void tegra_atomic_post_commit(struct drm_device *drm,
+				     struct drm_atomic_state *old_state)
+{
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	struct drm_crtc *crtc;
+	unsigned int i;
+
+	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state,
+				      new_crtc_state, i) {
+		if (!new_crtc_state->active)
+			continue;
+
+		tegra_crtc_atomic_post_commit(crtc, old_crtc_state);
+	}
+}
+
 static void tegra_atomic_commit_tail(struct drm_atomic_state *old_state)
 {
 	struct drm_device *drm = old_state->dev;
@@ -75,6 +92,8 @@ static void tegra_atomic_commit_tail(struct drm_atomic_state *old_state)
 	} else {
 		drm_atomic_helper_commit_tail_rpm(old_state);
 	}
+
+	tegra_atomic_post_commit(drm, old_state);
 }
 
 static const struct drm_mode_config_helper_funcs
diff --git a/drivers/gpu/drm/tegra/plane.c b/drivers/gpu/drm/tegra/plane.c
index 4cd0461cc508..8f6ef5fb3977 100644
--- a/drivers/gpu/drm/tegra/plane.c
+++ b/drivers/gpu/drm/tegra/plane.c
@@ -64,6 +64,7 @@ tegra_plane_atomic_duplicate_state(struct drm_plane *plane)
 	copy->reflect_x = state->reflect_x;
 	copy->reflect_y = state->reflect_y;
 	copy->opaque = state->opaque;
+	copy->memory_bandwidth = state->memory_bandwidth;
 
 	for (i = 0; i < 2; i++)
 		copy->blending[i] = state->blending[i];
diff --git a/drivers/gpu/drm/tegra/plane.h b/drivers/gpu/drm/tegra/plane.h
index c691dd79b27b..f9a031a69161 100644
--- a/drivers/gpu/drm/tegra/plane.h
+++ b/drivers/gpu/drm/tegra/plane.h
@@ -52,10 +52,12 @@ struct tegra_plane_state {
 	/* used for legacy blending support only */
 	struct tegra_plane_legacy_blending_state blending[2];
 	bool opaque;
+
+	unsigned long memory_bandwidth;
 };
 
 static inline struct tegra_plane_state *
-to_tegra_plane_state(struct drm_plane_state *state)
+to_tegra_plane_state(const struct drm_plane_state *state)
 {
 	if (state)
 		return container_of(state, struct tegra_plane_state, base);
-- 
2.27.0

[PATCH v5 35/36] drm/tegra: dc: Tune up high priority request controls for Tegra20

[Dmitry Osipenko]

Tegra20 has a high-priority-request control that allows to configure
when display's memory client should perform read requests with a higher
priority (Tegra30+ uses other means like Latency Allowance).

This patch changes the controls configuration in order to get a more
aggressive memory prefetching, which allows to reliably avoid FIFO
underflow when running on a lower memory frequency. This allow us
safely drop the memory bandwidth requirement by about two times in a
most popular use-cases (only one display active, video overlay inactive,
no scaling is done).

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/gpu/drm/tegra/dc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 850fbcebefc2..4b062408467e 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1999,12 +1999,12 @@ static void tegra_crtc_atomic_enable(struct drm_crtc *crtc,
 		tegra_dc_writel(dc, value, DC_CMD_INT_POLARITY);
 
 		/* initialize timer */
-		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0x20) |
-			WINDOW_B_THRESHOLD(0x20) | WINDOW_C_THRESHOLD(0x20);
+		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0x70) |
+			WINDOW_B_THRESHOLD(0x30) | WINDOW_C_THRESHOLD(0x70);
 		tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY);
 
-		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(1) |
-			WINDOW_B_THRESHOLD(1) | WINDOW_C_THRESHOLD(1);
+		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0) |
+			WINDOW_B_THRESHOLD(0) | WINDOW_C_THRESHOLD(0);
 		tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY_TIMER);
 
 		value = VBLANK_INT | WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |
-- 
2.27.0

[PATCH v5 36/36] drm/tegra: dc: Extend debug stats with total number of events

[Dmitry Osipenko]

It's useful to know the total number of underflow events and currently
the debug stats are getting reset each time CRTC is being disabled. Let's
account the overall number of events that doesn't get reset.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/gpu/drm/tegra/dc.c | 10 ++++++++++
 drivers/gpu/drm/tegra/dc.h |  5 +++++
 2 files changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 4b062408467e..0692b9f0ec29 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1644,6 +1644,11 @@ static int tegra_dc_show_stats(struct seq_file *s, void *data)
 	seq_printf(s, "underflow: %lu\n", dc->stats.underflow);
 	seq_printf(s, "overflow: %lu\n", dc->stats.overflow);
 
+	seq_printf(s, "frames total: %lu\n", dc->stats.frames_total);
+	seq_printf(s, "vblank total: %lu\n", dc->stats.vblank_total);
+	seq_printf(s, "underflow total: %lu\n", dc->stats.underflow_total);
+	seq_printf(s, "overflow total: %lu\n", dc->stats.overflow_total);
+
 	return 0;
 }
 
@@ -2206,6 +2211,7 @@ static irqreturn_t tegra_dc_irq(int irq, void *data)
 		/*
 		dev_dbg(dc->dev, "%s(): frame end\n", __func__);
 		*/
+		dc->stats.frames_total++;
 		dc->stats.frames++;
 	}
 
@@ -2214,6 +2220,7 @@ static irqreturn_t tegra_dc_irq(int irq, void *data)
 		dev_dbg(dc->dev, "%s(): vertical blank\n", __func__);
 		*/
 		drm_crtc_handle_vblank(&dc->base);
+		dc->stats.vblank_total++;
 		dc->stats.vblank++;
 	}
 
@@ -2221,6 +2228,7 @@ static irqreturn_t tegra_dc_irq(int irq, void *data)
 		/*
 		dev_dbg(dc->dev, "%s(): underflow\n", __func__);
 		*/
+		dc->stats.underflow_total++;
 		dc->stats.underflow++;
 	}
 
@@ -2228,11 +2236,13 @@ static irqreturn_t tegra_dc_irq(int irq, void *data)
 		/*
 		dev_dbg(dc->dev, "%s(): overflow\n", __func__);
 		*/
+		dc->stats.overflow_total++;
 		dc->stats.overflow++;
 	}
 
 	if (status & HEAD_UF_INT) {
 		dev_dbg_ratelimited(dc->dev, "%s(): head underflow\n", __func__);
+		dc->stats.underflow_total++;
 		dc->stats.underflow++;
 	}
 
diff --git a/drivers/gpu/drm/tegra/dc.h b/drivers/gpu/drm/tegra/dc.h
index b70eeeee2033..41ca33abb84c 100644
--- a/drivers/gpu/drm/tegra/dc.h
+++ b/drivers/gpu/drm/tegra/dc.h
@@ -41,6 +41,11 @@ struct tegra_dc_stats {
 	unsigned long vblank;
 	unsigned long underflow;
 	unsigned long overflow;
+
+	unsigned long frames_total;
+	unsigned long vblank_total;
+	unsigned long underflow_total;
+	unsigned long overflow_total;
 };
 
 struct tegra_windowgroup_soc {
-- 
2.27.0