soc/tegra: Enable flowctrl support for Tegra132/210

The flowctrl modules is supported by both Tegra132 and Tegra210 devices. These devices already have the flowctrl node defined in their respective *.dtsi device-tree files. The flowctrl driver is currently located in the arch/arm/mach-tegra directory and so can only be used for 32-bit Tegra devices. Move this driver into drivers/soc/tegra so that it can be used for all Tegra devices that support flowctrl.

I have also added a couple clean-up patches.

Changes since V1:
- Updated warning message per Thierry's feedback
- Added stub functions for public flowctrl APIs
- Added patch to register flowctrl driver as a platform driver
- Updated formatting of DT compatible strings per Thierry's feedback.

Jon Hunter (5):
ARM: tegra: Remove unnecessary inclusion of flowctrl header soc/tegra: Move Tegra flowctrl driver
soc/tegra: flowctrl: Add basic platform driver
dt-bindings: tegra: Update compatible strings for Tegra flowctrl soc/tegra: Add initial flowctrl support for Tegra132/210

 .../bindings/arm/tegra/nvidia,tegra20-flowctrl.txt |   7 +-
 arch/arm/mach-tegra/Makefile                       |   1 -
 arch/arm/mach-tegra/cpuidle-tegra20.c              |   3 +-
 arch/arm/mach-tegra/flowctrl.c                     | 179 ----------------
 arch/arm/mach-tegra/flowctrl.h                     |  66 ------
 arch/arm/mach-tegra/platsmp.c                      |   2 +-
 arch/arm/mach-tegra/pm.c                           |   2 +-
 arch/arm/mach-tegra/reset-handler.S                |   2 +-
 arch/arm/mach-tegra/sleep-tegra20.S                |   3 +-
 arch/arm/mach-tegra/sleep-tegra30.S                |   2 +-
 arch/arm/mach-tegra/sleep.S                        |   2 -
 arch/arm/mach-tegra/tegra.c                        |   2 -
 drivers/soc/tegra/Kconfig                          |   9 +
 drivers/soc/tegra/Makefile                         |   1 +
 drivers/soc/tegra/flowctrl.c                       | 224 +++++++++++++++++++++
 include/soc/tegra/flowctrl.h                       |  82 ++++++++
 16 files changed, 330 insertions(+), 257 deletions(-)
 delete mode 100644 arch/arm/mach-tegra/flowctrl.c
 delete mode 100644 arch/arm/mach-tegra/flowctrl.h
 create mode 100644 drivers/soc/tegra/flowctrl.c
 create mode 100644 include/soc/tegra/flowctrl.h

2.7.4

The Tegra flowctrl.h header is included unnecessarily by the Tegra sleep.S source file. Remove this unnecessary inclusion.

---
 arch/arm/mach-tegra/sleep.S | 2 --
 1 file changed, 2 deletions(-)

index f024a5109e8e..5e3496753df1 100644
@@ -30,8 +30,6 @@
 #include <asm/hardware/cache-l2x0.h>
 
 #include "iomap.h"
-
-#include "flowctrl.h"
 #include "sleep.h"
 
 #define CLK_RESET_CCLK_BURST	0x20

2.7.4

The flowctrl driver is required for both ARM and ARM64 Tegra devices and in order to enable support for it for ARM64, move the Tegra flowctrl driver into drivers/soc/tegra.

By moving the flowctrl driver, tegra_flowctrl_init() is now called by via an early initcall and to prevent this function from attempting to mapping IO space for a non-Tegra device, a test for 'soc_is_tegra()' is also added.

---
 arch/arm/mach-tegra/Makefile          |   1 -
 arch/arm/mach-tegra/cpuidle-tegra20.c |   3 +-
 arch/arm/mach-tegra/flowctrl.c        | 179 --------------------------------
 arch/arm/mach-tegra/flowctrl.h        |  66 ------------
 arch/arm/mach-tegra/platsmp.c         |   2 +-
 arch/arm/mach-tegra/pm.c              |   2 +-
 arch/arm/mach-tegra/reset-handler.S   |   2 +-
 arch/arm/mach-tegra/sleep-tegra20.S   |   3 +-
 arch/arm/mach-tegra/sleep-tegra30.S   |   2 +-
 arch/arm/mach-tegra/tegra.c           |   2 -
 drivers/soc/tegra/Kconfig             |   7 ++
 drivers/soc/tegra/Makefile            |   1 +
 drivers/soc/tegra/flowctrl.c          | 187 ++++++++++++++++++++++++++++++++++
 include/soc/tegra/flowctrl.h          |  82 +++++++++++++++
 14 files changed, 285 insertions(+), 254 deletions(-)
 delete mode 100644 arch/arm/mach-tegra/flowctrl.c
 delete mode 100644 arch/arm/mach-tegra/flowctrl.h
 create mode 100644 drivers/soc/tegra/flowctrl.c
 create mode 100644 include/soc/tegra/flowctrl.h

index fffad2426ee4..3b33f0bb78ae 100644
@@ -2,7 +2,6 @@ asflags-y				+= -march=armv7-a
 
 obj-y                                   += io.o
 obj-y                                   += irq.o
-obj-y					+= flowctrl.o
 obj-y					+= pm.o
 obj-y					+= reset.o
 obj-y					+= reset-handler.o

index afcee04f2616..76e4c83cd5c8 100644
@@ -26,12 +26,13 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 
+#include <soc/tegra/flowctrl.h>
+
 #include <asm/cpuidle.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 
 #include "cpuidle.h"
-#include "flowctrl.h"
 #include "iomap.h"
 #include "irq.h"
 #include "pm.h"

index 75620ae73913..b5a2afe99101 100644
@@ -21,6 +21,7 @@
 #include <linux/jiffies.h>
 #include <linux/smp.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 #include <soc/tegra/pmc.h>
 

@@ -30,7 +31,6 @@
 #include <asm/smp_scu.h>
 
 #include "common.h"
-#include "flowctrl.h"
 #include "iomap.h"
 #include "reset.h"
 

index b0f48a3946fa..1ad5719779b0 100644
@@ -27,6 +27,7 @@
 #include <linux/spinlock.h>
 #include <linux/suspend.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 #include <soc/tegra/pm.h>
 #include <soc/tegra/pmc.h>

@@ -38,7 +39,6 @@
 #include <asm/suspend.h>
 #include <asm/tlbflush.h>
 
-#include "flowctrl.h"
 #include "iomap.h"
 #include "pm.h"
 #include "reset.h"

index e3070fdab80b..805f306fa6f7 100644
@@ -17,12 +17,12 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
 
-#include "flowctrl.h"
 #include "iomap.h"
 #include "reset.h"
 #include "sleep.h"

index f5d19667484e..5c8e638ee51a 100644
@@ -20,6 +20,8 @@
 
 #include <linux/linkage.h>
 
+#include <soc/tegra/flowctrl.h>
+
 #include <asm/assembler.h>
 #include <asm/proc-fns.h>
 #include <asm/cp15.h>

@@ -27,7 +29,6 @@
 
 #include "irammap.h"
 #include "sleep.h"
-#include "flowctrl.h"
 
 #define EMC_CFG				0xc
 #define EMC_ADR_CFG			0x10

index 16e5ff03383c..dd4a67dabd91 100644
@@ -16,13 +16,13 @@
 
 #include <linux/linkage.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 
 #include <asm/asm-offsets.h>
 #include <asm/assembler.h>
 #include <asm/cache.h>
 
-#include "flowctrl.h"
 #include "irammap.h"
 #include "sleep.h"
 

index e01cbca196b5..649e9e8c7bcc 100644
@@ -48,7 +48,6 @@
 #include "board.h"
 #include "common.h"
 #include "cpuidle.h"
-#include "flowctrl.h"
 #include "iomap.h"
 #include "irq.h"
 #include "pm.h"

@@ -75,7 +74,6 @@ static void __init tegra_init_early(void)
 {
 	of_register_trusted_foundations();
 	tegra_cpu_reset_handler_init();
-	tegra_flowctrl_init();
 }
 
 static void __init tegra_dt_init_irq(void)

index 208d6edb3fdb..c7e8ddfb574e 100644
@@ -12,6 +12,7 @@ config ARCH_TEGRA_2x_SOC
 	select PINCTRL_TEGRA20
 	select PL310_ERRATA_727915 if CACHE_L2X0
 	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help

@@ -24,6 +25,7 @@ config ARCH_TEGRA_3x_SOC
 	select ARM_ERRATA_764369 if SMP
 	select PINCTRL_TEGRA30
 	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help

@@ -35,6 +37,7 @@ config ARCH_TEGRA_114_SOC
 	select ARM_ERRATA_798181 if SMP
 	select HAVE_ARM_ARCH_TIMER
 	select PINCTRL_TEGRA114
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help

@@ -45,6 +48,7 @@ config ARCH_TEGRA_124_SOC
 	bool "Enable support for Tegra124 family"
 	select HAVE_ARM_ARCH_TIMER
 	select PINCTRL_TEGRA124
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help

@@ -101,6 +105,9 @@ config ARCH_TEGRA_186_SOC
 endif
 endif
 
+config SOC_TEGRA_FLOWCTRL
+	bool
+
 config SOC_TEGRA_PMC
 	bool
 

index b4425e4319ff..4f81dd55e5d1 100644
@@ -1,5 +1,6 @@
 obj-y += fuse/
 
 obj-y += common.o
+obj-$(CONFIG_SOC_TEGRA_FLOWCTRL) += flowctrl.o
 obj-$(CONFIG_SOC_TEGRA_PMC) += pmc.o
 obj-$(CONFIG_SOC_TEGRA_PMC_TEGRA186) += pmc-tegra186.o

2.7.4

Add a simple platform driver for the flowctrl module so that it gets registered as a proper device.

---
 drivers/soc/tegra/flowctrl.c | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

index 3a5a1cb9ae90..25eddfc8475d 100644
@@ -24,6 +24,7 @@
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/platform_device.h>
 
 #include <soc/tegra/common.h>
 #include <soc/tegra/flowctrl.h>

@@ -47,7 +48,7 @@ static void __iomem *tegra_flowctrl_base;
 
 static void flowctrl_update(u8 offset, u32 value)
 {
-	if (WARN_ONCE(!tegra_flowctrl_base,
+	if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
 		      "Tegra flowctrl not initialised!\n"))
 		return;
 

@@ -62,7 +63,7 @@ u32 flowctrl_read_cpu_csr(unsigned int cpuid)
 {
 	u8 offset = flowctrl_offset_cpu_csr[cpuid];
 
-	if (WARN_ONCE(!tegra_flowctrl_base,
+	if (WARN_ONCE(IS_ERR_OR_NULL(tegra_flowctrl_base),
 		      "Tegra flowctrl not initialised!\n"))
 		return 0;
 

@@ -148,7 +149,22 @@ void flowctrl_cpu_suspend_exit(unsigned int cpuid)
 	flowctrl_write_cpu_csr(cpuid, reg);
 }
 
-static const struct of_device_id matches[] __initconst = {
+static int tegra_flowctrl_probe(struct platform_device *pdev)
+{
+	void __iomem *base = tegra_flowctrl_base;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	tegra_flowctrl_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tegra_flowctrl_base))
+		return PTR_ERR(base);
+
+	iounmap(base);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_flowctrl_match[] = {
 	{ .compatible = "nvidia,tegra124-flowctrl" },
 	{ .compatible = "nvidia,tegra114-flowctrl" },
 	{ .compatible = "nvidia,tegra30-flowctrl" },

@@ -156,6 +172,16 @@ static const struct of_device_id matches[] __initconst = {
 	{ }
 };
 
+static struct platform_driver tegra_flowctrl_driver = {
+	.driver = {
+		.name = "tegra-flowctrl",
+		.suppress_bind_attrs = true,
+		.of_match_table = tegra_flowctrl_match,
+	},
+	.probe = tegra_flowctrl_probe,
+};
+builtin_platform_driver(tegra_flowctrl_driver);
+
 static int __init tegra_flowctrl_init(void)
 {
 	/* hardcoded fallback if device tree node is missing */

@@ -166,7 +192,7 @@ static int __init tegra_flowctrl_init(void)
 	if (!soc_is_tegra())
 		return 0;
 
-	np = of_find_matching_node(NULL, matches);
+	np = of_find_matching_node(NULL, tegra_flowctrl_match);
 	if (np) {
 		struct resource res;
 

2.7.4

Update the compatible strings for Tegra Flow Control driver to match the device-tree source files for Tegra.

---
 .../devicetree/bindings/arm/tegra/nvidia,tegra20-flowctrl.txt      | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

index ccf0adddc820..49587485de1f 100644
@@ -1,7 +1,12 @@
 NVIDIA Tegra Flow Controller
 
 Required properties:
-- compatible: Should be "nvidia,tegra<chip>-flowctrl"
+- compatible: Should contain one of the following:
+  - "nvidia,tegra20-flowctrl": for Tegra20
+  - "nvidia,tegra30-flowctrl": for Tegra30
+  - "nvidia,tegra114-flowctrl": for Tegra114
+  - "nvidia,tegra124-flowctrl": for Tegra124 and Tegra132
+  - "nvidia,tegra210-flowctrl": for Tegra210
 - reg: Should contain one register range (address and length)
 
 Example:

2.7.4

I think that should be:

+ - "nvidia,tegra124-flowctrl": for Tegra124
+ - "nvidia,tegra132-flowctrl", "nvidia,tegra124-flowctrl": for \
Tegra132

This is based upon the current tegra132.dtsi file which just has ...

	flow-controller at 60007000 {
		compatible = "nvidia,tegra124-flowctrl";
		...

So I can fix-it up if that is what we want/should have. I have a feeling there are a few other cases like this.

Cheers
Jon

nvpublic

Yes, I'm sure we have some escapes right now. In practice we currently treat T124 and T132 as almost/entirely identical so it won't make any difference. In theory it might in the future if we find a T132-specific bug (unlikely, but). If you're editing up the compatible value docs, we may as well fix this issue while we're at it:-) Scope creep:-) This could happen in a separate change if you want, e.g. to make the same edit to all T132 or all Tegra DTs.

Tegra132 and Tegra210 support the flowctrl module and so add initial support for these devices.

Please note that Tegra186 does not support the flowctrl module, so update the initialisation function such that we do not fall back and attempt to map the 'hardcoded' address range for Tegra186. Furthermore 64-bit Tegra devices have always had the flowctrl node defined in their device-tree and so only use the 'hardcoded' addresses for 32-bit Tegra devices.

---
 drivers/soc/tegra/Kconfig    |  2 ++
 drivers/soc/tegra/flowctrl.c | 31 +++++++++++++++++++++----------
 2 files changed, 23 insertions(+), 10 deletions(-)

index c7e8ddfb574e..dcf088db40b6 100644
@@ -63,6 +63,7 @@ if ARM64
 config ARCH_TEGRA_132_SOC
 	bool "NVIDIA Tegra132 SoC"
 	select PINCTRL_TEGRA124
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	help
 	  Enable support for NVIDIA Tegra132 SoC, based on the Denver

@@ -73,6 +74,7 @@ config ARCH_TEGRA_132_SOC
 config ARCH_TEGRA_210_SOC
 	bool "NVIDIA Tegra210 SoC"
 	select PINCTRL_TEGRA210
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	help
 	  Enable support for the NVIDIA Tegra210 SoC. Also known as Tegra X1,

index 25eddfc8475d..0e345c05fc65 100644
@@ -165,6 +165,7 @@ static int tegra_flowctrl_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id tegra_flowctrl_match[] = {
+	{ .compatible = "nvidia,tegra210-flowctrl" },
 	{ .compatible = "nvidia,tegra124-flowctrl" },
 	{ .compatible = "nvidia,tegra114-flowctrl" },
 	{ .compatible = "nvidia,tegra30-flowctrl" },

@@ -184,9 +185,7 @@ builtin_platform_driver(tegra_flowctrl_driver);
 
 static int __init tegra_flowctrl_init(void)
 {
-	/* hardcoded fallback if device tree node is missing */
-	unsigned long base = 0x60007000;
-	unsigned long size = SZ_4K;
+	struct resource res;
 	struct device_node *np;
 
 	if (!soc_is_tegra())

@@ -194,17 +193,29 @@ static int __init tegra_flowctrl_init(void)
 
 	np = of_find_matching_node(NULL, tegra_flowctrl_match);
 	if (np) {
-		struct resource res;
-
-		if (of_address_to_resource(np, 0, &res) == 0) {
-			size = resource_size(&res);
-			base = res.start;
+		if (of_address_to_resource(np, 0, &res) < 0) {
+			pr_err("failed to get flowctrl register\n");
+			return -ENXIO;
 		}
-
 		of_node_put(np);
+	} else if (IS_ENABLED(CONFIG_ARM)) {
+		/*
+		 * Hardcoded fallback for 32-bit Tegra
+		 * devices if device tree node is missing.
+		 */
+		res.start = 0x60007000;
+		res.end = 0x60007fff;
+		res.flags = IORESOURCE_MEM;
+	} else {
+		/*
+		 * At this point we're running on a Tegra,
+		 * that doesn't support the flow controller
+		 * (eg. Tegra186), so just return.
+		 */
+		return 0;
 	}
 
-	tegra_flowctrl_base = ioremap_nocache(base, size);
+	tegra_flowctrl_base = ioremap_nocache(res.start, resource_size(&res));
 	if (!tegra_flowctrl_base)
 		return -ENXIO;
 

2.7.4