[PATCH 00/14] Add support to STMicroelectronics STM32 family

[PATCH 00/14] Add support to STMicroelectronics STM32 family

[Maxime Coquelin]

This patchset adds basic support for STMicroelectronics STM32 series MCUs.

STM32 MCUs are Cortex-M CPU, used in various applications (consumer
electronics, industrial applications, hobbyists...).
Datasheets, user and programming manuals are publicly available on
STMicroelectronics website.

With this series applied, the STM32F419 Discovery can boot succesfully.

Once this series accepted, next steps will be to add DMA support, as USART,
I2C and SPI IPs don't have any FIFO. Then will come the clock driver, as today
the bootloader has to be patched to enable the needed clocks.

Maxime Coquelin (14):
  scripts: link-vmlinux: Don't pass page offset to kallsyms if XIP
    Kernel
  ARM: ARMv7M: Enlarge vector table to 256 entries
  clocksource: Add ARM System timer driver
  reset: Add reset_controller_of_init() function
  ARM: call reset_controller_of_init from default time_init handler
  drivers: reset: Add STM32 reset driver
  clockevent: Add STM32 Timer driver
  pinctrl: Add pinctrl driver for STM32 MCUs
  serial: stm32-usart: Add STM32 USART Driver
  ARM: Add STM32 family machine
  ARM: dts: Add ARM System timer as clockevent in armv7m
  ARM: dts: Introduce STM32F429 MCU
  ARM: configs: Add STM32 defconfig
  MAINTAINERS: Add entry for STM32 MCUs

 Documentation/arm/stm32/overview.txt               |  32 +
 Documentation/arm/stm32/stm32f429-overview.txt     |  22 +
 .../devicetree/bindings/arm/system_timer.txt       |  15 +
 .../devicetree/bindings/pinctrl/pinctrl-stm32.txt  |  99 +++
 .../devicetree/bindings/reset/st,stm32-reset.txt   |  19 +
 .../devicetree/bindings/serial/st,stm32-usart.txt  |  18 +
 .../devicetree/bindings/timer/st,stm32-timer.txt   |  19 +
 MAINTAINERS                                        |   7 +
 arch/arm/Kconfig                                   |  22 +
 arch/arm/Makefile                                  |   1 +
 arch/arm/boot/dts/Makefile                         |   1 +
 arch/arm/boot/dts/armv7-m.dtsi                     |   7 +
 arch/arm/boot/dts/stm32f429-disco.dts              |  41 ++
 arch/arm/boot/dts/stm32f429.dtsi                   | 279 ++++++++
 arch/arm/configs/stm32_defconfig                   |  72 ++
 arch/arm/kernel/entry-v7m.S                        |   8 +-
 arch/arm/kernel/time.c                             |   4 +
 arch/arm/mach-stm32/Makefile                       |   1 +
 arch/arm/mach-stm32/Makefile.boot                  |   0
 arch/arm/mach-stm32/board-dt.c                     |  19 +
 drivers/clocksource/Kconfig                        |  16 +
 drivers/clocksource/Makefile                       |   2 +
 drivers/clocksource/arm_system_timer.c             |  74 ++
 drivers/clocksource/timer-stm32.c                  | 187 +++++
 drivers/pinctrl/Kconfig                            |   9 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/pinctrl-stm32.c                    | 779 +++++++++++++++++++++
 drivers/reset/Makefile                             |   1 +
 drivers/reset/core.c                               |  20 +
 drivers/reset/reset-stm32.c                        | 124 ++++
 drivers/tty/serial/Kconfig                         |  17 +
 drivers/tty/serial/Makefile                        |   1 +
 drivers/tty/serial/stm32-usart.c                   | 695 ++++++++++++++++++
 include/asm-generic/vmlinux.lds.h                  |   4 +-
 include/dt-bindings/pinctrl/pinctrl-stm32.h        |  43 ++
 include/linux/reset-controller.h                   |   6 +
 include/uapi/linux/serial_core.h                   |   3 +
 scripts/link-vmlinux.sh                            |   2 +-
 38 files changed, 2664 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/arm/stm32/overview.txt
 create mode 100644 Documentation/arm/stm32/stm32f429-overview.txt
 create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
 create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
 create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-reset.txt
 create mode 100644 Documentation/devicetree/bindings/serial/st,stm32-usart.txt
 create mode 100644 Documentation/devicetree/bindings/timer/st,stm32-timer.txt
 create mode 100644 arch/arm/boot/dts/stm32f429-disco.dts
 create mode 100644 arch/arm/boot/dts/stm32f429.dtsi
 create mode 100644 arch/arm/configs/stm32_defconfig
 create mode 100644 arch/arm/mach-stm32/Makefile
 create mode 100644 arch/arm/mach-stm32/Makefile.boot
 create mode 100644 arch/arm/mach-stm32/board-dt.c
 create mode 100644 drivers/clocksource/arm_system_timer.c
 create mode 100644 drivers/clocksource/timer-stm32.c
 create mode 100644 drivers/pinctrl/pinctrl-stm32.c
 create mode 100644 drivers/reset/reset-stm32.c
 create mode 100644 drivers/tty/serial/stm32-usart.c
 create mode 100644 include/dt-bindings/pinctrl/pinctrl-stm32.h

-- 
1.9.1

[PATCH 01/14] scripts: link-vmlinux: Don't pass page offset to kallsyms if XIP Kernel

[Maxime Coquelin]

When Kernel is executed in place from ROM, the symbol addresses can be
lower than the page offset.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 scripts/link-vmlinux.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 86a4fe7..b055d9d 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -82,7 +82,7 @@ kallsyms()
 		kallsymopt="${kallsymopt} --all-symbols"
 	fi
 
-	if [ -n "${CONFIG_ARM}" ] && [ -n "${CONFIG_PAGE_OFFSET}" ]; then
+	if [ -n "${CONFIG_ARM}" ] && [ -z "${CONFIG_XIP_KERNEL}" ] && [ -n "${CONFIG_PAGE_OFFSET}" ]; then
 		kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET"
 	fi
 
-- 
1.9.1

[PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Maxime Coquelin]

>From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
interrupts. So the number of entries in vectors table is 256.

This patch adds the missing entries, and change the alignement, so that
vector_table remains naturally aligned.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 arch/arm/kernel/entry-v7m.S | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/entry-v7m.S b/arch/arm/kernel/entry-v7m.S
index 8944f49..29a461b 100644
--- a/arch/arm/kernel/entry-v7m.S
+++ b/arch/arm/kernel/entry-v7m.S
@@ -117,9 +117,9 @@ ENTRY(__switch_to)
 ENDPROC(__switch_to)
 
 	.data
-	.align	8
+	.align	10
 /*
- * Vector table (64 words => 256 bytes natural alignment)
+ * Vector table (256 words => 1024 bytes alignment)
  */
 ENTRY(vector_table)
 	.long	0			@ 0 - Reset stack pointer
@@ -138,6 +138,6 @@ ENTRY(vector_table)
 	.long	__invalid_entry		@ 13 - Reserved
 	.long	__pendsv_entry		@ 14 - PendSV
 	.long	__invalid_entry		@ 15 - SysTick
-	.rept	64 - 16
-	.long	__irq_entry		@ 16..64 - External Interrupts
+	.rept	256 - 16
+	.long	__irq_entry		@ 16..256 - External Interrupts
 	.endr
-- 
1.9.1

[PATCH 03/14] clocksource: Add ARM System timer driver

[Maxime Coquelin]

This patch adds clocksource support for ARMv7-M's System timer,
also known as SysTick.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 .../devicetree/bindings/arm/system_timer.txt       | 15 +++++
 drivers/clocksource/Kconfig                        |  7 ++
 drivers/clocksource/Makefile                       |  1 +
 drivers/clocksource/arm_system_timer.c             | 74 ++++++++++++++++++++++
 4 files changed, 97 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
 create mode 100644 drivers/clocksource/arm_system_timer.c

diff --git a/Documentation/devicetree/bindings/arm/system_timer.txt b/Documentation/devicetree/bindings/arm/system_timer.txt
new file mode 100644
index 0000000..35268b7
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/system_timer.txt
@@ -0,0 +1,15 @@
+* ARM System Timer
+
+ARMv7-M includes a system timer, known as SysTick. Current driver only
+implements the clocksource feature.
+
+Required properties:
+- compatible : Should be "arm,armv7m-systick"
+- reg	     : The address range of the timer
+- clocks     : The input clock of the timer
+
+systick: system-timer {
+	compatible = "arm,armv7m-systick";
+	reg = <0xe000e010 0x10>;
+	clocks = <&clk_systick>;
+};
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index fc01ec2..f9fe4ac 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -124,6 +124,13 @@ config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
 	help
 	 Use ARM global timer clock source as sched_clock
 
+config ARM_SYSTEM_TIMER
+	bool
+	select CLKSRC_OF if OF
+	select CLKSRC_MMIO
+	help
+	  This options enables support for the ARM system timer unit
+
 config ATMEL_PIT
 	select CLKSRC_OF if OF
 	def_bool SOC_AT91SAM9 || SOC_SAMA5
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 94d90b2..194400b 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_MTK_TIMER)		+= mtk_timer.o
 
 obj-$(CONFIG_ARM_ARCH_TIMER)		+= arm_arch_timer.o
 obj-$(CONFIG_ARM_GLOBAL_TIMER)		+= arm_global_timer.o
+obj-$(CONFIG_ARM_SYSTEM_TIMER)		+= arm_system_timer.o
 obj-$(CONFIG_CLKSRC_METAG_GENERIC)	+= metag_generic.o
 obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)	+= dummy_timer.o
 obj-$(CONFIG_ARCH_KEYSTONE)		+= timer-keystone.o
diff --git a/drivers/clocksource/arm_system_timer.c b/drivers/clocksource/arm_system_timer.c
new file mode 100644
index 0000000..69e6ef9
--- /dev/null
+++ b/drivers/clocksource/arm_system_timer.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/kernel.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/clk.h>
+#include <linux/bitops.h>
+
+#define SYST_CSR	0x00
+#define SYST_RVR	0x04
+#define SYST_CVR	0x08
+#define SYST_CALIB	0x0c
+
+#define SYST_CSR_ENABLE BIT(0)
+
+#define SYSTICK_LOAD_RELOAD_MASK 0x00FFFFFF
+
+static void __init system_timer_of_register(struct device_node *np)
+{
+	struct clk *clk;
+	void __iomem *base;
+	unsigned long rate;
+	int ret;
+
+	base = of_iomap(np, 0);
+	if (!base) {
+		pr_warn("system-timer: invalid base address\n");
+		return;
+	}
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_warn("system-timer: clk not found\n");
+		ret = PTR_ERR(clk);
+		goto out_unmap;
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		goto out_clk_put;
+
+	rate = clk_get_rate(clk);
+
+	writel_relaxed(SYSTICK_LOAD_RELOAD_MASK, base + SYST_RVR);
+	writel_relaxed(SYST_CSR_ENABLE, base + SYST_CSR);
+
+	ret = clocksource_mmio_init(base + SYST_CVR, "arm_system_timer", rate,
+			200, 24, clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("failed to init clocksource (%d)\n", ret);
+		goto out_clk_disable;
+	}
+
+	pr_info("ARM System timer initialized as clocksource\n");
+
+	return;
+
+out_clk_disable:
+	clk_disable_unprepare(clk);
+out_clk_put:
+	clk_put(clk);
+out_unmap:
+	iounmap(base);
+	WARN(ret, "ARM System timer register failed (%d)\n", ret);
+}
+
+CLOCKSOURCE_OF_DECLARE(arm_systick, "arm,armv7m-systick",
+			system_timer_of_register);
-- 
1.9.1

[PATCH 04/14] reset: Add reset_controller_of_init() function

[Maxime Coquelin]

Some platforms need to initialize the reset controller before the timers.

This patch introduces a reset_controller_of_init() function that can be
called before the timers intialization.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 drivers/reset/core.c              | 20 ++++++++++++++++++++
 include/asm-generic/vmlinux.lds.h |  4 +++-
 include/linux/reset-controller.h  |  6 ++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 7955e00..18ee579 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -86,6 +86,26 @@ void reset_controller_unregister(struct reset_controller_dev *rcdev)
 }
 EXPORT_SYMBOL_GPL(reset_controller_unregister);
 
+extern struct of_device_id __reset_ctrl_of_table[];
+
+static const struct of_device_id __reset_ctrl_of_table_sentinel
+	__used __section(__reset_ctrl_of_table_end);
+
+void __init reset_controller_of_init(void)
+{
+	struct device_node *np;
+	const struct of_device_id *match;
+	of_init_fn_1 init_func;
+
+	for_each_matching_node_and_match(np, __reset_ctrl_of_table, &match) {
+		if (!of_device_is_available(np))
+			continue;
+
+		init_func = match->data;
+		init_func(np);
+	}
+}
+
 /**
  * reset_control_reset - reset the controlled device
  * @rstc: reset controller
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index bee5d68..1f96365 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -168,6 +168,7 @@
 #define RESERVEDMEM_OF_TABLES()	OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
 #define CPU_METHOD_OF_TABLES()	OF_TABLE(CONFIG_SMP, cpu_method)
 #define EARLYCON_OF_TABLES()	OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon)
+#define RESET_CTRL_OF_TABLES()	OF_TABLE(CONFIG_RESET_CONTROLLER, reset_ctrl)
 
 #define KERNEL_DTB()							\
 	STRUCT_ALIGN();							\
@@ -502,7 +503,8 @@
 	CPU_METHOD_OF_TABLES()						\
 	KERNEL_DTB()							\
 	IRQCHIP_OF_MATCH_TABLE()					\
-	EARLYCON_OF_TABLES()
+	EARLYCON_OF_TABLES()						\
+	RESET_CTRL_OF_TABLES()
 
 #define INIT_TEXT							\
 	*(.init.text)							\
diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
index ce6b962..f8a030a 100644
--- a/include/linux/reset-controller.h
+++ b/include/linux/reset-controller.h
@@ -51,4 +51,10 @@ struct reset_controller_dev {
 int reset_controller_register(struct reset_controller_dev *rcdev);
 void reset_controller_unregister(struct reset_controller_dev *rcdev);
 
+
+#define RESET_CONTROLLER_OF_DECLARE(name, compat, fn) \
+	OF_DECLARE_1(reset_ctrl, name, compat, fn)
+
+void reset_controller_of_init(void);
+
 #endif
-- 
1.9.1

[PATCH 05/14] ARM: call reset_controller_of_init from default time_init handler

[Maxime Coquelin]

Some DT ARM platforms need the reset controllers to be initialized before
the timers.
This is the case of the stm32 and sunxi platforms.

This patch adds a call to reset_controller_of_init() to the default
.init_time callback when RESET_CONTROLLER is used by the platform.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 arch/arm/kernel/time.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index 0cc7e58..4601b1e 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -20,6 +20,7 @@
 #include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/profile.h>
+#include <linux/reset-controller.h>
 #include <linux/sched.h>
 #include <linux/sched_clock.h>
 #include <linux/smp.h>
@@ -117,6 +118,9 @@ void __init time_init(void)
 	if (machine_desc->init_time) {
 		machine_desc->init_time();
 	} else {
+#ifdef CONFIG_RESET_CONTROLLER
+		reset_controller_of_init();
+#endif
 #ifdef CONFIG_COMMON_CLK
 		of_clk_init(NULL);
 #endif
-- 
1.9.1

[PATCH 06/14] drivers: reset: Add STM32 reset driver

[Maxime Coquelin]

The STM32 MCUs family IP can be reset by accessing some shared registers.

The specificity is that some reset lines are used by the timers.
At timer initialization time, the timer has to be reset, that's why
we cannot use a regular driver.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 .../devicetree/bindings/reset/st,stm32-reset.txt   |  19 ++++
 drivers/reset/Makefile                             |   1 +
 drivers/reset/reset-stm32.c                        | 124 +++++++++++++++++++++
 3 files changed, 144 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-reset.txt
 create mode 100644 drivers/reset/reset-stm32.c

diff --git a/Documentation/devicetree/bindings/reset/st,stm32-reset.txt b/Documentation/devicetree/bindings/reset/st,stm32-reset.txt
new file mode 100644
index 0000000..add1298
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/st,stm32-reset.txt
@@ -0,0 +1,19 @@
+STMicroelectronics STM32 Peripheral Reset Controller
+====================================================
+
+Please also refer to reset.txt in this directory for common reset
+controller binding usage.
+
+Required properties:
+- compatible: Should be "st,stm32-reset"
+- reg: should be register base and length as documented in the
+  datasheet
+- #reset-cells: 1, see below
+
+example:
+
+reset_ahb1: reset@40023810 {
+	#reset-cells = <1>;
+	compatible = "st,stm32-reset";
+	reg = <0x40023810 0x4>;
+};
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 157d421..aed12d1 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_RESET_CONTROLLER) += core.o
 obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
 obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
+obj-$(CONFIG_ARCH_STM32) += reset-stm32.o
 obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_ARCH_STI) += sti/
diff --git a/drivers/reset/reset-stm32.c b/drivers/reset/reset-stm32.c
new file mode 100644
index 0000000..7a96677
--- /dev/null
+++ b/drivers/reset/reset-stm32.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * Heavily based on sunxi driver from Maxime Ripard.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+struct stm32_reset_data {
+	spinlock_t			lock;
+	void __iomem			*membase;
+	struct reset_controller_dev	rcdev;
+};
+
+static int stm32_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct stm32_reset_data *data = container_of(rcdev,
+						     struct stm32_reset_data,
+						     rcdev);
+	int bank = id / BITS_PER_LONG;
+	int offset = id % BITS_PER_LONG;
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	reg = readl_relaxed(data->membase + (bank * 4));
+	writel_relaxed(reg | BIT(offset), data->membase + (bank * 4));
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static int stm32_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct stm32_reset_data *data = container_of(rcdev,
+						     struct stm32_reset_data,
+						     rcdev);
+	int bank = id / BITS_PER_LONG;
+	int offset = id % BITS_PER_LONG;
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	reg = readl_relaxed(data->membase + (bank * 4));
+	writel_relaxed(reg & ~BIT(offset), data->membase + (bank * 4));
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static struct reset_control_ops stm32_reset_ops = {
+	.assert		= stm32_reset_assert,
+	.deassert	= stm32_reset_deassert,
+};
+
+static void stm32_reset_init(struct device_node *np)
+{
+	struct stm32_reset_data *data;
+	struct resource res;
+	resource_size_t size;
+	int err;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return;
+
+	err = of_address_to_resource(np, 0, &res);
+	if (err)
+		goto err_alloc;
+
+	size = resource_size(&res);
+	if (!request_mem_region(res.start, size, np->name)) {
+		err = -EINVAL;
+		goto err_alloc;
+	}
+
+	data->membase = ioremap(res.start, size);
+	if (!data->membase) {
+		err = -ENOMEM;
+		goto err_alloc;
+	}
+
+	spin_lock_init(&data->lock);
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.nr_resets = size * 8;
+	data->rcdev.ops = &stm32_reset_ops;
+	data->rcdev.of_node = np;
+
+	err = reset_controller_register(&data->rcdev);
+	if (err)
+		goto err_iomap;
+
+	pr_info("%s: %d reset lines registered\n", np->full_name,
+			data->rcdev.nr_resets);
+	return;
+
+err_iomap:
+	iounmap(data->membase);
+err_alloc:
+	kfree(data);
+	pr_err("%s: Reset ctrl registration failed (%d).\n",
+			np->full_name, err);
+}
+
+RESET_CONTROLLER_OF_DECLARE(stm32, "st,stm32-reset", stm32_reset_init);
+
-- 
1.9.1

[PATCH 07/14] clockevent: Add STM32 Timer driver

[Maxime Coquelin]

STM32 MCUs feature 16 and 32 bits general purpose timers with prescalers.
The drivers detects whether the time is 16 or 32 bits, and applies a
1024 prescaler value if it is 16 bits.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 .../devicetree/bindings/timer/st,stm32-timer.txt   |  19 +++
 drivers/clocksource/Kconfig                        |   9 +
 drivers/clocksource/Makefile                       |   1 +
 drivers/clocksource/timer-stm32.c                  | 187 +++++++++++++++++++++
 4 files changed, 216 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/timer/st,stm32-timer.txt
 create mode 100644 drivers/clocksource/timer-stm32.c

diff --git a/Documentation/devicetree/bindings/timer/st,stm32-timer.txt b/Documentation/devicetree/bindings/timer/st,stm32-timer.txt
new file mode 100644
index 0000000..7fffcd8
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/st,stm32-timer.txt
@@ -0,0 +1,19 @@
+. STMicroelectronics STM32 timer
+
+The STM32 MCUs family has several general-purpose 16 and 32 bits timers.
+
+Required properties:
+- compatible : Should be st,stm32-timer"
+- reg : Address and length of the register set
+- clocks : Reference on the timer input clock
+- interrupts : Reference to the timer interrupt
+
+Example:
+
+timer5: timer@40000c00 {
+	compatible = "st,stm32-timer";
+	reg = <0x40000c00 0x400>;
+	interrupts = <50>;
+	resets = <&reset_apb1 3>;
+	clocks = <&clk_pmtr1>;
+};
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index f9fe4ac..74b60a7 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -91,6 +91,15 @@ config CLKSRC_EFM32
 	  Support to use the timers of EFM32 SoCs as clock source and clock
 	  event device.
 
+config CLKSRC_STM32
+	bool "Clocksource for STM32 SoCs" if !ARCH_STM32
+	depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST)
+	select CLKSRC_MMIO
+	default ARCH_STM32
+	help
+	  Support to use the timers of STM32 SoCs as clock source and clock
+	  event device.
+
 config ARM_ARCH_TIMER
 	bool
 	select CLKSRC_OF if OF
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 194400b..16a7c6c 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_ARCH_NSPIRE)	+= zevio-timer.o
 obj-$(CONFIG_ARCH_BCM_MOBILE)	+= bcm_kona_timer.o
 obj-$(CONFIG_CADENCE_TTC_TIMER)	+= cadence_ttc_timer.o
 obj-$(CONFIG_CLKSRC_EFM32)	+= time-efm32.o
+obj-$(CONFIG_CLKSRC_STM32)	+= timer-stm32.o
 obj-$(CONFIG_CLKSRC_EXYNOS_MCT)	+= exynos_mct.o
 obj-$(CONFIG_CLKSRC_SAMSUNG_PWM)	+= samsung_pwm_timer.o
 obj-$(CONFIG_FSL_FTM_TIMER)	+= fsl_ftm_timer.o
diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c
new file mode 100644
index 0000000..9839f57
--- /dev/null
+++ b/drivers/clocksource/timer-stm32.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * Inspired by time-efm32.c from Uwe Kleine-Koenig
+ */
+
+#include <linux/kernel.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+
+#define TIM_CR1		0x00
+#define TIM_DIER	0x0c
+#define TIM_SR		0x10
+#define TIM_EGR		0x14
+#define TIM_PSC		0x28
+#define TIM_ARR		0x2c
+
+#define TIM_CR1_CEN	BIT(0)
+#define TIM_CR1_OPM	BIT(3)
+#define TIM_CR1_ARPE	BIT(7)
+
+#define TIM_DIER_UIE	BIT(0)
+
+#define TIM_SR_UIF	BIT(0)
+
+#define TIM_EGR_UG	BIT(0)
+
+struct stm32_clock_event_ddata {
+	struct clock_event_device evtdev;
+	unsigned periodic_top;
+	void __iomem *base;
+};
+
+static void stm32_clock_event_set_mode(enum clock_event_mode mode,
+				       struct clock_event_device *evtdev)
+{
+	struct stm32_clock_event_ddata *data =
+		container_of(evtdev, struct stm32_clock_event_ddata, evtdev);
+	void *base = data->base;
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		writel_relaxed(data->periodic_top, base + TIM_ARR);
+		writel_relaxed(TIM_CR1_ARPE | TIM_CR1_CEN, base + TIM_CR1);
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+	default:
+		writel_relaxed(0, base + TIM_CR1);
+		break;
+	}
+}
+
+static int stm32_clock_event_set_next_event(unsigned long evt,
+					    struct clock_event_device *evtdev)
+{
+	struct stm32_clock_event_ddata *data =
+		container_of(evtdev, struct stm32_clock_event_ddata, evtdev);
+
+	writel_relaxed(evt, data->base + TIM_ARR);
+	writel_relaxed(TIM_CR1_ARPE | TIM_CR1_OPM | TIM_CR1_CEN,
+		       data->base + TIM_CR1);
+
+	return 0;
+}
+
+static irqreturn_t stm32_clock_event_handler(int irq, void *dev_id)
+{
+	struct stm32_clock_event_ddata *data = dev_id;
+
+	writel_relaxed(0, data->base + TIM_SR);
+
+	data->evtdev.event_handler(&data->evtdev);
+
+	return IRQ_HANDLED;
+}
+
+static struct stm32_clock_event_ddata clock_event_ddata = {
+	.evtdev = {
+		.name = "stm32 clockevent",
+		.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+		.set_mode = stm32_clock_event_set_mode,
+		.set_next_event = stm32_clock_event_set_next_event,
+		.rating = 200,
+	},
+};
+
+static void __init stm32_clockevent_init(struct device_node *np)
+{
+	struct stm32_clock_event_ddata *data = &clock_event_ddata;
+	struct clk *clk;
+	struct reset_control *rstc;
+	unsigned long rate, max_delta;
+	int irq, ret, bits, prescaler = 1;
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		pr_err("failed to get clock for clockevent (%d)\n", ret);
+		goto err_clk_get;
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		pr_err("failed to enable timer clock for clockevent (%d)\n",
+		       ret);
+		goto err_clk_enable;
+	}
+
+	rate = clk_get_rate(clk);
+
+	rstc = of_reset_control_get(np, NULL);
+	if (IS_ERR(rstc)) {
+		pr_err("%s: Failed to get reset\n", np->full_name);
+		return;
+	}
+
+	reset_control_assert(rstc);
+	reset_control_deassert(rstc);
+
+	data->base = of_iomap(np, 0);
+	if (!data->base) {
+		pr_err("failed to map registers for clockevent\n");
+		goto err_iomap;
+	}
+
+	irq = irq_of_parse_and_map(np, 0);
+	if (!irq) {
+		pr_err("%s: failed to get irq.\n", np->full_name);
+		goto err_get_irq;
+	}
+
+	/* Detect whether the timer is 16 or 32 bits */
+	writel_relaxed(~0UL, data->base + TIM_ARR);
+	max_delta = readl_relaxed(data->base + TIM_ARR);
+	if (max_delta == ~0UL) {
+		prescaler = 1;
+		bits = 32;
+	} else {
+		prescaler = 1024;
+		bits = 16;
+	}
+	writel_relaxed(0, data->base + TIM_ARR);
+
+	writel_relaxed(prescaler - 1, data->base + TIM_PSC);
+	writel_relaxed(TIM_EGR_UG, data->base + TIM_EGR);
+	writel_relaxed(TIM_DIER_UIE, data->base + TIM_DIER);
+	writel_relaxed(0, data->base + TIM_SR);
+
+	data->periodic_top = DIV_ROUND_CLOSEST(rate, prescaler * HZ);
+
+	clockevents_config_and_register(&data->evtdev,
+					DIV_ROUND_CLOSEST(rate, prescaler),
+					0x1, max_delta);
+
+	ret = request_irq(irq, stm32_clock_event_handler, IRQF_TIMER,
+			"stm32 clockevent", data);
+	if (ret) {
+		pr_err("%s: failed to request irq.\n", np->full_name);
+		goto err_get_irq;
+	}
+
+	pr_info("%s: STM32 clockevent driver initialized (%d bits)\n",
+			np->full_name, bits);
+
+	return;
+
+err_get_irq:
+	iounmap(data->base);
+err_iomap:
+	clk_disable_unprepare(clk);
+err_clk_enable:
+	clk_put(clk);
+err_clk_get:
+	return;
+}
+
+CLOCKSOURCE_OF_DECLARE(stm32, "st,stm32-timer", stm32_clockevent_init);
-- 
1.9.1

[PATCH 08/14] pinctrl: Add pinctrl driver for STM32 MCUs

[Maxime Coquelin]

This driver adds pinctrl and GPIO support to STMicrolectronic's
STM32 family of MCUs.

Pin muxing and GPIO handling have been tested on STM32F429
based Discovery board.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 .../devicetree/bindings/pinctrl/pinctrl-stm32.txt  |  99 +++
 drivers/pinctrl/Kconfig                            |   9 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/pinctrl-stm32.c                    | 779 +++++++++++++++++++++
 include/dt-bindings/pinctrl/pinctrl-stm32.h        |  43 ++
 5 files changed, 931 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
 create mode 100644 drivers/pinctrl/pinctrl-stm32.c
 create mode 100644 include/dt-bindings/pinctrl/pinctrl-stm32.h

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
new file mode 100644
index 0000000..0fb5b24
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
@@ -0,0 +1,99 @@
+* STM32 GPIO and Pin Mux/Config controller
+
+STMicroelectronics's STM32 MCUs intregrate a GPIO and Pin mux/config hardware
+controller. It controls the input/output settings on the available pins and
+also provides ability to multiplex and configure the output of various on-chip
+controllers onto these pads.
+
+Pin controller node:
+Required properies:
+- compatible	: "st,stm32-pinctrl"
+- #address-cells: The value of this property must be 1
+- #size-cells	: The value of this property must be 1
+- ranges	: defines mapping between pin controller node (parent) to
+  gpio-bank node (children).
+
+GPIO controller/bank node:
+Required properties:
+- gpio-controller : Indicates this device is a GPIO controller
+- #gpio-cells	  : Should be two.
+			The first cell is the pin number
+			The second one is the polarity:
+				- 0 for active high
+				- 1 for active low
+- reg		  : The gpio address range, relative to the pinctrl range
+- st,bank-name	  : Should be a name string for this bank as specified in
+  the datasheet
+
+Optional properties:
+- reset:	  : Reference to the reset controller
+
+Example:
+#include <dt-bindings/pinctrl/pinctrl-stm32.h>
+...
+
+	pin-controller {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "st,stm32-pinctrl";
+		ranges = <0 0x40020000 0x3000>;
+
+		gpioa: gpio@40020000 {
+			gpio-controller;
+			#gpio-cells = <2>;
+			reg = <0x0 0x400>;
+			resets = <&reset_ahb1 0>;
+			st,bank-name = "GPIOA";
+		};
+		...
+		pin-functions nodes follow...
+	};
+
+Contents of function subnode node:
+----------------------------------
+
+Required properties for pin configuration node:
+- st,pins	: Child node with list of pins with configuration.
+
+Below is the format of how each pin conf should look like.
+
+<bank offset altmode pull type speed>
+
+Every PIO is represented with 4 to 6 parameters.
+Each parameter is explained as below.
+
+- bank	  : Should be bank phandle to which this PIO belongs.
+- offset  : Offset in the PIO bank.
+- altmode : Should be mode or alternate function number associated this pin, as
+described in the datasheet (IN, OUT, ALT0...ALT15, ANALOG)
+- pull	  : Should be either NO_PULL, PULL_UP or PULL_DOWN
+- type	  : Should be either PUSH_PULL or OPEN_DRAIN.
+	    Setting it is not needed for IN and ANALOG modes, or alternate
+	    functions acting as inputs.
+- speed	  : Value taken from the datasheet, depending on the function
+(LOW_SPEED, MEDIUM_SPEED, FAST_SPEED, HIGH_SPEED)
+	    Setting it is not needed for IN and ANALOG modes, or alternate
+	    functions acting as inputs.
+
+usart1 {
+	pinctrl_usart1: usart1-0 {
+		st,pins {
+			tx = <&gpioa 9 ALT7 NO_PULL PUSH_PULL LOW_SPEED>;
+			rx = <&gpioa 10 ALT7 NO_PULL PUSH_PULL LOW_SPEED>;
+		};
+	};
+};
+
+adc2 {
+	pinctrl_adc2: adc2-0 {
+		st,pins {
+			adc0 = <&gpioe 4 ANALOG NO_PULL>;
+		};
+	};
+};
+
+usart1: usart@40011000 {
+	...
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_usart1>;
+};
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index d014f22..af242bb 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -125,6 +125,15 @@ config PINCTRL_ST
 	select PINCONF
 	select GPIOLIB_IRQCHIP
 
+config PINCTRL_STM32
+	bool "STMicroelectronics STM32 pinctrl driver"
+	depends on OF
+	select PINMUX
+	select PINCONF
+	select GPIOLIB_IRQCHIP
+	help
+	  This selects the device tree based generic pinctrl driver for STM32.
+
 config PINCTRL_TEGRA
 	bool
 	select PINMUX
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index c030b3d..06ef8ab 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_PINCTRL_XWAY)	+= pinctrl-xway.o
 obj-$(CONFIG_PINCTRL_LANTIQ)	+= pinctrl-lantiq.o
 obj-$(CONFIG_PINCTRL_TB10X)	+= pinctrl-tb10x.o
 obj-$(CONFIG_PINCTRL_ST) 	+= pinctrl-st.o
+obj-$(CONFIG_PINCTRL_STM32) 	+= pinctrl-stm32.o
 
 obj-$(CONFIG_ARCH_BERLIN)	+= berlin/
 obj-y				+= freescale/
diff --git a/drivers/pinctrl/pinctrl-stm32.c b/drivers/pinctrl/pinctrl-stm32.c
new file mode 100644
index 0000000..5c474b0
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-stm32.c
@@ -0,0 +1,779 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * Heavily based on pinctrl-st.c from Srinivas Kandagatla
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_address.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include "core.h"
+
+#define STM32_GPIO_MODER	0x00
+#define STM32_GPIO_TYPER	0x04
+#define STM32_GPIO_SPEEDR	0x08
+#define STM32_GPIO_PUPDR	0x0c
+#define STM32_GPIO_IDR		0x10
+#define STM32_GPIO_ODR		0x14
+#define STM32_GPIO_BSRR		0x18
+#define STM32_GPIO_LCKR		0x1c
+#define STM32_GPIO_AFRL		0x20
+#define STM32_GPIO_AFRH		0x24
+
+#define STM32_GPIO_PINS_PER_BANK 16
+#define OF_GPIO_ARGS_MIN 4
+
+#define STM32_PINCONF_UNPACK(conf, param)\
+				((conf >> STM32_PINCONF_ ##param ##_SHIFT) \
+				& STM32_PINCONF_ ##param ##_MASK)
+
+#define STM32_PINCONF_PACK(conf, val, param)	(conf |=\
+				((val & STM32_PINCONF_ ##param ##_MASK) << \
+					STM32_PINCONF_ ##param ##_SHIFT))
+
+#define STM32_PINCONF_SPEED_MASK		0x3
+#define STM32_PINCONF_SPEED_SHIFT		3
+#define STM32_PINCONF_UNPACK_SPEED(conf)\
+				STM32_PINCONF_UNPACK(conf, SPEED)
+#define STM32_PINCONF_PACK_SPEED(conf, val)\
+				STM32_PINCONF_PACK(conf, val, SPEED)
+
+#define STM32_PINCONF_TYPE_MASK			0x1
+#define STM32_PINCONF_TYPE_SHIFT		2
+#define STM32_PINCONF_UNPACK_TYPE(conf)\
+				STM32_PINCONF_UNPACK(conf, TYPE)
+#define STM32_PINCONF_PACK_TYPE(conf, val)\
+				STM32_PINCONF_PACK(conf, val, TYPE)
+
+#define STM32_PINCONF_PUPD_MASK			0x3
+#define STM32_PINCONF_PUPD_SHIFT		0
+#define STM32_PINCONF_UNPACK_PUPD(conf)\
+				STM32_PINCONF_UNPACK(conf, PUPD)
+#define STM32_PINCONF_PACK_PUPD(conf, val)\
+				STM32_PINCONF_PACK(conf, val, PUPD)
+
+
+#define STM32_PINCONF_ALT_MASK			0xf
+#define STM32_PINCONF_ALT_SHIFT		2
+#define STM32_PINCONF_UNPACK_ALT(conf)\
+				STM32_PINCONF_UNPACK(conf, ALT)
+#define STM32_PINCONF_PACK_ALT(conf, val)\
+				STM32_PINCONF_PACK(conf, val, ALT)
+
+#define STM32_PINCONF_MODE_MASK			0x3
+#define STM32_PINCONF_MODE_SHIFT		0
+#define STM32_PINCONF_UNPACK_MODE(conf)\
+				STM32_PINCONF_UNPACK(conf, MODE)
+#define STM32_PINCONF_PACK_MODE(conf, val)\
+				STM32_PINCONF_PACK(conf, val, MODE)
+
+
+
+#define gpio_range_to_bank(chip) \
+		container_of(chip, struct stm32_gpio_bank, range)
+
+#define gpio_chip_to_bank(chip) \
+		container_of(chip, struct stm32_gpio_bank, gpio_chip)
+
+struct stm32_pinconf {
+	int		pin;
+	const char	*name;
+	unsigned long	config;
+	int		altfunc;
+};
+
+struct stm32_pmx_func {
+	const char	*name;
+	const char	**groups;
+	unsigned	ngroups;
+};
+
+struct stm32_pctl_group {
+	const char		*name;
+	unsigned int		*pins;
+	unsigned		npins;
+	struct stm32_pinconf	*pin_conf;
+};
+
+struct stm32_gpio_bank {
+	void __iomem *base;
+	struct gpio_chip		gpio_chip;
+	struct pinctrl_gpio_range	range;
+	spinlock_t                      lock;
+};
+
+struct stm32_pinctrl {
+	struct device		*dev;
+	struct pinctrl_dev		*pctl;
+	struct stm32_gpio_bank	*banks;
+	int			nbanks;
+	struct stm32_pmx_func	*functions;
+	int			nfunctions;
+	struct stm32_pctl_group	*groups;
+	int			ngroups;
+};
+
+static inline int stm32_gpio_pin(int gpio)
+{
+	return gpio % STM32_GPIO_PINS_PER_BANK;
+}
+
+/* Pinconf  */
+static void stm32_pinconf_set_config(struct stm32_gpio_bank *bank,
+				int pin, unsigned long config)
+{
+	u32 type, speed, pupd, val;
+	unsigned long flags;
+
+	type = STM32_PINCONF_UNPACK_TYPE(config);
+	spin_lock_irqsave(&bank->lock, flags);
+	val = readl_relaxed(bank->base + STM32_GPIO_TYPER);
+	val &= ~BIT(pin);
+	val |= type << pin;
+	writel_relaxed(val, bank->base + STM32_GPIO_TYPER);
+	spin_unlock_irqrestore(&bank->lock, flags);
+
+	speed = STM32_PINCONF_UNPACK_SPEED(config);
+	spin_lock_irqsave(&bank->lock, flags);
+	val = readl_relaxed(bank->base + STM32_GPIO_SPEEDR);
+	val &= ~GENMASK(pin * 2 + 1, pin * 2);
+	val |= speed << (pin * 2);
+	writel_relaxed(val, bank->base + STM32_GPIO_SPEEDR);
+	spin_unlock_irqrestore(&bank->lock, flags);
+
+	pupd = STM32_PINCONF_UNPACK_PUPD(config);
+	spin_lock_irqsave(&bank->lock, flags);
+	val = readl_relaxed(bank->base + STM32_GPIO_PUPDR);
+	val &= ~GENMASK(pin * 2 + 1, pin * 2);
+	val |= pupd << (pin * 2);
+	writel_relaxed(val, bank->base + STM32_GPIO_PUPDR);
+	spin_unlock_irqrestore(&bank->lock, flags);
+}
+
+static void stm32_pinconf_get_config(struct stm32_gpio_bank *bank,
+				int pin, unsigned long *config)
+{
+	u32 val;
+
+	val = readl_relaxed(bank->base + STM32_GPIO_TYPER);
+	val = val >> pin;
+	STM32_PINCONF_PACK_TYPE(*config, val);
+
+	val = readl_relaxed(bank->base + STM32_GPIO_SPEEDR);
+	val = val >> (pin * 2);
+	STM32_PINCONF_PACK_SPEED(*config, val);
+
+	val = readl_relaxed(bank->base + STM32_GPIO_PUPDR);
+	val = val >> (pin * 2);
+	STM32_PINCONF_PACK_PUPD(*config, val);
+}
+
+static int stm32_pinconf_set(struct pinctrl_dev *pctldev, unsigned pin_id,
+			unsigned long *configs, unsigned num_configs)
+{
+	struct pinctrl_gpio_range *range =
+			 pinctrl_find_gpio_range_from_pin(pctldev, pin_id);
+	struct stm32_gpio_bank *bank = gpio_range_to_bank(range);
+	int pin = stm32_gpio_pin(pin_id);
+	int i;
+
+	for (i = 0; i < num_configs; i++)
+		stm32_pinconf_set_config(bank, pin, configs[i]);
+
+	return 0;
+}
+
+static int stm32_pinconf_get(struct pinctrl_dev *pctldev,
+			     unsigned pin_id, unsigned long *config)
+{
+	struct pinctrl_gpio_range *range =
+			 pinctrl_find_gpio_range_from_pin(pctldev, pin_id);
+	struct stm32_gpio_bank *bank = gpio_range_to_bank(range);
+	int pin = stm32_gpio_pin(pin_id);
+
+	*config = 0;
+	stm32_pinconf_get_config(bank, pin, config);
+
+	return 0;
+}
+
+static void stm32_pinconf_dbg_show(struct pinctrl_dev *pctldev,
+				   struct seq_file *s, unsigned pin_id)
+{
+	unsigned long config;
+
+	stm32_pinconf_get(pctldev, pin_id, &config);
+
+	seq_printf(s, "[PUPD:%ld,TYPE:%ld,SPEED:%ld]\n",
+		STM32_PINCONF_UNPACK_PUPD(config),
+		STM32_PINCONF_UNPACK_TYPE(config),
+		STM32_PINCONF_UNPACK_SPEED(config));
+}
+
+static struct pinconf_ops stm32_confops = {
+	.pin_config_get		= stm32_pinconf_get,
+	.pin_config_set		= stm32_pinconf_set,
+	.pin_config_dbg_show	= stm32_pinconf_dbg_show,
+};
+
+static void stm32_pctl_set_function(struct stm32_gpio_bank *bank,
+		int pin_id, int function)
+{
+	u32 mode, alt, val;
+	int pin = stm32_gpio_pin(pin_id);
+	int alt_shift = (pin % 8) * 4;
+	int alt_offset = STM32_GPIO_AFRL + (pin / 8) * 4;
+	unsigned long flags;
+
+	mode = STM32_PINCONF_UNPACK_MODE(function);
+	alt = STM32_PINCONF_UNPACK_ALT(function);
+
+	spin_lock_irqsave(&bank->lock, flags);
+
+	val = readl_relaxed(bank->base + alt_offset);
+	val &= ~GENMASK(alt_shift + 3, alt_shift);
+	val |= (alt << alt_shift);
+	writel_relaxed(val, bank->base + alt_offset);
+
+	val = readl_relaxed(bank->base + STM32_GPIO_MODER);
+	val &= ~GENMASK(pin * 2 + 1, pin * 2);
+	val |= mode << (pin * 2);
+	writel_relaxed(val, bank->base + STM32_GPIO_MODER);
+
+	spin_unlock_irqrestore(&bank->lock, flags);
+}
+
+/* Pinmux */
+static int stm32_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->nfunctions;
+}
+
+static const char *stm32_pmx_get_fname(struct pinctrl_dev *pctldev,
+	unsigned selector)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->functions[selector].name;
+}
+
+static int stm32_pmx_get_groups(struct pinctrl_dev *pctldev,
+	unsigned selector, const char * const **grps, unsigned * const ngrps)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	*grps = info->functions[selector].groups;
+	*ngrps = info->functions[selector].ngroups;
+
+	return 0;
+}
+
+static int stm32_pmx_set_mux(struct pinctrl_dev *pctldev, unsigned fselector,
+			unsigned group)
+{
+	struct pinctrl_gpio_range *range;
+	struct stm32_gpio_bank *bank;
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	struct stm32_pinconf *conf = info->groups[group].pin_conf;
+	int i;
+
+	for (i = 0; i < info->groups[group].npins; i++) {
+		range = pinctrl_find_gpio_range_from_pin(pctldev, conf[i].pin);
+		bank = gpio_range_to_bank(range);
+		stm32_pctl_set_function(bank, conf[i].pin, conf[i].altfunc);
+	}
+
+	return 0;
+}
+
+static int stm32_pmx_set_gpio_direction(struct pinctrl_dev *pctldev,
+			struct pinctrl_gpio_range *range, unsigned gpio,
+			bool input)
+{
+	struct stm32_gpio_bank *bank = gpio_range_to_bank(range);
+
+	stm32_pctl_set_function(bank, gpio, !input);
+
+	return 0;
+}
+
+static struct pinmux_ops stm32_pmxops = {
+	.get_functions_count	= stm32_pmx_get_funcs_count,
+	.get_function_name	= stm32_pmx_get_fname,
+	.get_function_groups	= stm32_pmx_get_groups,
+	.set_mux		= stm32_pmx_set_mux,
+	.gpio_set_direction	= stm32_pmx_set_gpio_direction,
+};
+
+/* Pinctrl Groups */
+static int stm32_pctl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->ngroups;
+}
+
+static const char *stm32_pctl_get_group_name(struct pinctrl_dev *pctldev,
+				       unsigned selector)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->groups[selector].name;
+}
+
+static int stm32_pctl_get_group_pins(struct pinctrl_dev *pctldev,
+	unsigned selector, const unsigned **pins, unsigned *npins)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	if (selector >= info->ngroups)
+		return -EINVAL;
+
+	*pins = info->groups[selector].pins;
+	*npins = info->groups[selector].npins;
+
+	return 0;
+}
+
+static const inline struct stm32_pctl_group *stm32_pctl_find_group_by_name(
+	const struct stm32_pinctrl *info, const char *name)
+{
+	int i;
+
+	for (i = 0; i < info->ngroups; i++) {
+		if (!strcmp(info->groups[i].name, name))
+			return &info->groups[i];
+	}
+
+	return NULL;
+}
+
+static int stm32_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
+	struct device_node *np, struct pinctrl_map **map, unsigned *num_maps)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	const struct stm32_pctl_group *grp;
+	struct pinctrl_map *new_map;
+	struct device_node *parent;
+	int map_num, i;
+
+	grp = stm32_pctl_find_group_by_name(info, np->name);
+	if (!grp) {
+		dev_err(info->dev, "unable to find group for node %s\n",
+			np->name);
+		return -EINVAL;
+	}
+
+	map_num = grp->npins + 1;
+	new_map = devm_kzalloc(pctldev->dev,
+				sizeof(*new_map) * map_num, GFP_KERNEL);
+	if (!new_map)
+		return -ENOMEM;
+
+	parent = of_get_parent(np);
+	if (!parent) {
+		devm_kfree(pctldev->dev, new_map);
+		return -EINVAL;
+	}
+
+	*map = new_map;
+	*num_maps = map_num;
+	new_map[0].type = PIN_MAP_TYPE_MUX_GROUP;
+	new_map[0].data.mux.function = parent->name;
+	new_map[0].data.mux.group = np->name;
+	of_node_put(parent);
+
+	/* create config map per pin */
+	new_map++;
+	for (i = 0; i < grp->npins; i++) {
+		new_map[i].type = PIN_MAP_TYPE_CONFIGS_PIN;
+		new_map[i].data.configs.group_or_pin =
+				pin_get_name(pctldev, grp->pins[i]);
+		new_map[i].data.configs.configs = &grp->pin_conf[i].config;
+		new_map[i].data.configs.num_configs = 1;
+	}
+	dev_info(pctldev->dev, "maps: function %s group %s num %d\n",
+		(*map)->data.mux.function, grp->name, map_num);
+
+	return 0;
+}
+
+static void stm32_pctl_dt_free_map(struct pinctrl_dev *pctldev,
+			struct pinctrl_map *map, unsigned num_maps)
+{
+}
+
+static struct pinctrl_ops stm32_pctlops = {
+	.get_groups_count	= stm32_pctl_get_groups_count,
+	.get_group_pins		= stm32_pctl_get_group_pins,
+	.get_group_name		= stm32_pctl_get_group_name,
+	.dt_node_to_map		= stm32_pctl_dt_node_to_map,
+	.dt_free_map		= stm32_pctl_dt_free_map,
+};
+
+static void stm32_pctl_dt_child_count(struct stm32_pinctrl *info,
+				     struct device_node *np)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(np, child) {
+		if (of_property_read_bool(child, "gpio-controller")) {
+			info->nbanks++;
+		} else {
+			info->nfunctions++;
+			info->ngroups += of_get_child_count(child);
+		}
+	}
+}
+
+static int stm32_pctl_dt_parse_groups(struct device_node *np,
+	struct stm32_pctl_group *grp, struct stm32_pinctrl *info, int idx)
+{
+	const __be32 *list;
+	struct property *pp;
+	struct stm32_pinconf *conf;
+	struct device_node *pins;
+	int i = 0, npins = 0, nr_props;
+
+	pins = of_get_child_by_name(np, "st,pins");
+	if (!pins)
+		return -ENODATA;
+
+	for_each_property_of_node(pins, pp) {
+		/* Skip those we do not want to proceed */
+		if (!strcmp(pp->name, "name"))
+			continue;
+
+		if (pp  && (pp->length / sizeof(__be32)) >= OF_GPIO_ARGS_MIN) {
+			npins++;
+		} else {
+			pr_warn("Invalid st,pins in %s node\n", np->name);
+			return -EINVAL;
+		}
+	}
+
+	grp->npins = npins;
+	grp->name = np->name;
+	grp->pins = devm_kzalloc(info->dev, npins * sizeof(u32), GFP_KERNEL);
+	grp->pin_conf = devm_kzalloc(info->dev,
+					npins * sizeof(*conf), GFP_KERNEL);
+
+	if (!grp->pins || !grp->pin_conf)
+		return -ENOMEM;
+
+	/* <bank offset mux pull type speed> */
+	for_each_property_of_node(pins, pp) {
+		if (!strcmp(pp->name, "name"))
+			continue;
+		nr_props = pp->length / sizeof(u32);
+		list = pp->value;
+		conf = &grp->pin_conf[i];
+
+		/* bank & offset */
+		be32_to_cpup(list++);
+		be32_to_cpup(list++);
+		conf->pin = of_get_named_gpio(pins, pp->name, 0);
+		conf->name = pp->name;
+		grp->pins[i] = conf->pin;
+		/* mux */
+		conf->altfunc = be32_to_cpup(list++);
+		conf->config = 0;
+		/* pull-up/down */
+		conf->config |= be32_to_cpup(list++);
+		if (nr_props > OF_GPIO_ARGS_MIN) {
+			/* push-pull/open-drain */
+			conf->config |= be32_to_cpup(list++);
+			/* speed */
+			conf->config |= be32_to_cpup(list++);
+		}
+		i++;
+	}
+	of_node_put(pins);
+
+	return 0;
+}
+
+static int stm32_pctl_parse_functions(struct device_node *np,
+			struct stm32_pinctrl *info, u32 index, int *grp_index)
+{
+	struct device_node *child;
+	struct stm32_pmx_func *func;
+	struct stm32_pctl_group *grp;
+	int i = 0, ret;
+
+	func = &info->functions[index];
+	func->name = np->name;
+	func->ngroups = of_get_child_count(np);
+	if (func->ngroups == 0) {
+		dev_err(info->dev, "No groups defined\n");
+		return -EINVAL;
+	}
+	func->groups = devm_kzalloc(info->dev,
+			func->ngroups * sizeof(char *), GFP_KERNEL);
+	if (!func->groups)
+		return -ENOMEM;
+
+	for_each_child_of_node(np, child) {
+		func->groups[i] = child->name;
+		grp = &info->groups[*grp_index];
+		*grp_index += 1;
+		ret = stm32_pctl_dt_parse_groups(child, grp, info, i++);
+		if (ret)
+			return ret;
+	}
+	dev_info(info->dev, "Function[%d\t name:%s,\tgroups:%d]\n",
+				index, func->name, func->ngroups);
+
+	return 0;
+}
+
+static inline void __stm32_gpio_set(struct stm32_gpio_bank *bank,
+	unsigned offset, int value)
+{
+	if (!value)
+		offset += STM32_GPIO_PINS_PER_BANK;
+
+	writel_relaxed(BIT(offset), bank->base + STM32_GPIO_BSRR);
+}
+
+static int stm32_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void stm32_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	pinctrl_free_gpio(chip->base + offset);
+}
+
+static int stm32_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct stm32_gpio_bank *bank = gpio_chip_to_bank(chip);
+
+	return !!(readl_relaxed(bank->base + STM32_GPIO_IDR) & BIT(offset));
+}
+
+static void stm32_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct stm32_gpio_bank *bank = gpio_chip_to_bank(chip);
+
+	__stm32_gpio_set(bank, offset, value);
+}
+
+static int stm32_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	pinctrl_gpio_direction_input(chip->base + offset);
+
+	return 0;
+}
+
+static int stm32_gpio_direction_output(struct gpio_chip *chip,
+	unsigned offset, int value)
+{
+	struct stm32_gpio_bank *bank = gpio_chip_to_bank(chip);
+
+	__stm32_gpio_set(bank, offset, value);
+	pinctrl_gpio_direction_output(chip->base + offset);
+
+	return 0;
+}
+
+static struct gpio_chip stm32_gpio_template = {
+	.request		= stm32_gpio_request,
+	.free			= stm32_gpio_free,
+	.get			= stm32_gpio_get,
+	.set			= stm32_gpio_set,
+	.direction_input	= stm32_gpio_direction_input,
+	.direction_output	= stm32_gpio_direction_output,
+	.ngpio			= STM32_GPIO_PINS_PER_BANK,
+};
+
+static int stm32_gpiolib_register_bank(struct stm32_pinctrl *info,
+	int bank_nr, struct device_node *np)
+{
+	struct stm32_gpio_bank *bank = &info->banks[bank_nr];
+	struct pinctrl_gpio_range *range = &bank->range;
+	struct device *dev = info->dev;
+	struct resource res;
+	struct reset_control *rstc;
+	int bank_num = of_alias_get_id(np, "gpio");
+	int err;
+
+	rstc = of_reset_control_get(np, NULL);
+	if (!IS_ERR(rstc))
+		reset_control_deassert(rstc);
+
+	if (of_address_to_resource(np, 0, &res))
+		return -ENODEV;
+
+	bank->base = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(bank->base))
+		return PTR_ERR(bank->base);
+
+	bank->gpio_chip = stm32_gpio_template;
+	bank->gpio_chip.base = bank_num * STM32_GPIO_PINS_PER_BANK;
+	bank->gpio_chip.of_node = np;
+	bank->gpio_chip.dev = dev;
+	spin_lock_init(&bank->lock);
+
+	of_property_read_string(np, "st,bank-name", &range->name);
+	bank->gpio_chip.label = range->name;
+
+	range->id = bank_num;
+	range->pin_base = range->base = range->id * STM32_GPIO_PINS_PER_BANK;
+	range->npins = bank->gpio_chip.ngpio;
+	range->gc = &bank->gpio_chip;
+	err  = gpiochip_add(&bank->gpio_chip);
+	if (err) {
+		dev_err(dev, "Failed to add gpiochip(%d)!\n", bank_num);
+		return err;
+	}
+	dev_info(dev, "%s bank added.\n", range->name);
+
+	return 0;
+}
+
+static int stm32_pctl_probe_dt(struct platform_device *pdev,
+	struct pinctrl_desc *pctl_desc, struct stm32_pinctrl *info)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct pinctrl_pin_desc *pdesc;
+	struct device_node *child;
+	int grp_index = 0;
+	int i = 0, j = 0, k = 0, bank = 0,  ret = 0;
+
+	stm32_pctl_dt_child_count(info, np);
+	if (!info->nbanks) {
+		dev_err(&pdev->dev, "you need atleast one gpio bank\n");
+		return -EINVAL;
+	}
+
+	dev_info(&pdev->dev, "nbanks = %d\n", info->nbanks);
+	dev_info(&pdev->dev, "nfunctions = %d\n", info->nfunctions);
+	dev_info(&pdev->dev, "ngroups = %d\n", info->ngroups);
+
+	info->functions = devm_kzalloc(&pdev->dev,
+		info->nfunctions * sizeof(*info->functions), GFP_KERNEL);
+
+	info->groups = devm_kzalloc(&pdev->dev,
+			info->ngroups * sizeof(*info->groups), GFP_KERNEL);
+
+	info->banks = devm_kzalloc(&pdev->dev,
+			info->nbanks * sizeof(*info->banks), GFP_KERNEL);
+
+	if (!info->functions || !info->groups || !info->banks)
+		return -ENOMEM;
+
+	pctl_desc->npins = info->nbanks * STM32_GPIO_PINS_PER_BANK;
+	pdesc =	devm_kzalloc(&pdev->dev,
+			sizeof(*pdesc) * pctl_desc->npins, GFP_KERNEL);
+	if (!pdesc)
+		return -ENOMEM;
+
+	pctl_desc->pins = pdesc;
+
+	for_each_child_of_node(np, child) {
+		if (of_property_read_bool(child, "gpio-controller")) {
+			const char *bank_name;
+
+			ret = stm32_gpiolib_register_bank(info, bank, child);
+			if (ret)
+				return ret;
+
+			k = info->banks[bank].range.pin_base;
+			bank_name = info->banks[bank].range.name;
+			for (j = 0; j < STM32_GPIO_PINS_PER_BANK; j++, k++) {
+				pdesc->number = k;
+				pdesc->name = kasprintf(GFP_KERNEL, "%s[%d]",
+							bank_name, j);
+				pdesc++;
+			}
+			bank++;
+		} else {
+			ret = stm32_pctl_parse_functions(child, info,
+							i++, &grp_index);
+			if (ret) {
+				dev_err(&pdev->dev, "No functions found.\n");
+				return ret;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int stm32_pctl_probe(struct platform_device *pdev)
+{
+	struct stm32_pinctrl *info;
+	struct pinctrl_desc *pctl_desc;
+	int ret, i;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "device not found.\n");
+		return -EINVAL;
+	}
+
+	pctl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctl_desc), GFP_KERNEL);
+	if (!pctl_desc)
+		return -ENOMEM;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = &pdev->dev;
+	platform_set_drvdata(pdev, info);
+	ret = stm32_pctl_probe_dt(pdev, pctl_desc, info);
+	if (ret)
+		return ret;
+
+	pctl_desc->owner	= THIS_MODULE;
+	pctl_desc->pctlops	= &stm32_pctlops;
+	pctl_desc->pmxops	= &stm32_pmxops;
+	pctl_desc->confops	= &stm32_confops;
+	pctl_desc->name		= dev_name(&pdev->dev);
+
+	info->pctl = pinctrl_register(pctl_desc, &pdev->dev, info);
+	if (!info->pctl) {
+		dev_err(&pdev->dev, "Failed pinctrl registration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < info->nbanks; i++)
+		pinctrl_add_gpio_range(info->pctl, &info->banks[i].range);
+
+	return 0;
+}
+
+static struct of_device_id stm32_pctl_of_match[] = {
+	{ .compatible = "st,stm32-pinctrl" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver stm32_pctl_driver = {
+	.driver = {
+		.name = "stm32-pinctrl",
+		.owner = THIS_MODULE,
+		.of_match_table = stm32_pctl_of_match,
+	},
+	.probe = stm32_pctl_probe,
+};
+
+static int __init stm32_pctl_init(void)
+{
+	return platform_driver_register(&stm32_pctl_driver);
+}
+arch_initcall(stm32_pctl_init);
diff --git a/include/dt-bindings/pinctrl/pinctrl-stm32.h b/include/dt-bindings/pinctrl/pinctrl-stm32.h
new file mode 100644
index 0000000..3e93a86
--- /dev/null
+++ b/include/dt-bindings/pinctrl/pinctrl-stm32.h
@@ -0,0 +1,43 @@
+#ifndef _DT_BINDINGS_PINCTRL_STM32_H
+#define _DT_BINDINGS_PINCTRL_STM32_H
+
+/* Modes */
+#define IN		0
+#define OUT		1
+#define ALT		2
+#define ANALOG		3
+
+/* Alternate functions */
+#define ALT0		((0 << 2) | ALT)
+#define ALT1		((1 << 2) | ALT)
+#define ALT2		((2 << 2) | ALT)
+#define ALT3		((3 << 2) | ALT)
+#define ALT4		((4 << 2) | ALT)
+#define ALT5		((5 << 2) | ALT)
+#define ALT6		((6 << 2) | ALT)
+#define ALT7		((7 << 2) | ALT)
+#define ALT8		((8 << 2) | ALT)
+#define ALT9		((9 << 2) | ALT)
+#define ALT10		((10 << 2) | ALT)
+#define ALT11		((11 << 2) | ALT)
+#define ALT12		((12 << 2) | ALT)
+#define ALT13		((13 << 2) | ALT)
+#define ALT14		((14 << 2) | ALT)
+#define ALT15		((15 << 2) | ALT)
+
+/* Pull-Up/Down */
+#define NO_PULL		0
+#define PULL_UP		1
+#define PULL_DOWN	2
+
+/* Type */
+#define PUSH_PULL	(0 << 2)
+#define OPEN_DRAIN	(1 << 2)
+
+/* Speed */
+#define LOW_SPEED	(0 << 3)
+#define MEDIUM_SPEED	(1 << 3)
+#define FAST_SPEED	(2 << 3)
+#define HIGH_SPEED	(3 << 3)
+
+#endif /* _DT_BINDINGS_PINCTRL_STM32_H */
-- 
1.9.1

[PATCH 09/14] serial: stm32-usart: Add STM32 USART Driver

[Maxime Coquelin]

This drivers adds support to the STM32 USART controller, which is a
standard serial driver.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 .../devicetree/bindings/serial/st,stm32-usart.txt  |  18 +
 drivers/tty/serial/Kconfig                         |  17 +
 drivers/tty/serial/Makefile                        |   1 +
 drivers/tty/serial/stm32-usart.c                   | 695 +++++++++++++++++++++
 include/uapi/linux/serial_core.h                   |   3 +
 5 files changed, 734 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/serial/st,stm32-usart.txt
 create mode 100644 drivers/tty/serial/stm32-usart.c

diff --git a/Documentation/devicetree/bindings/serial/st,stm32-usart.txt b/Documentation/devicetree/bindings/serial/st,stm32-usart.txt
new file mode 100644
index 0000000..e49b75ad
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/st,stm32-usart.txt
@@ -0,0 +1,18 @@
+* STMicroelectronics STM32 USART
+
+Required properties:
+- compatible: Should be "st,stm32-usart"
+- reg: The address and length of the peripheral registers space
+- interrupts: The interrupt line of the USART instance
+- clocks: The input clock of the USART instance
+- pinctrl: The reference on the pins configuration
+
+Example:
+usart1: usart@40011000 {
+	compatible = "st,stm32-usart";
+	reg = <0x40011000 0x400>;
+	interrupts = <37>;
+	clocks = <&clk_pclk2>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_usart1>;
+};
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index c79b43c..b990bd4 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1577,6 +1577,23 @@ config SERIAL_MEN_Z135
 	  This driver can also be build as a module. If so, the module will be called
 	  men_z135_uart.ko
 
+config SERIAL_STM32
+	tristate "STMicroelectronics STM32 serial port support"
+	select SERIAL_CORE
+	depends on ARM || COMPILE_TEST
+	help
+	  This driver is for the on-chip Serial Controller on
+	  STMicroelectronics STM32 MCUs.
+	  USART supports Rx & Tx functionality.
+	  It support all industry standard baud rates.
+
+	  If unsure, say N.
+
+config SERIAL_STM32_CONSOLE
+	bool "Support for console on STM32"
+	depends on SERIAL_STM32=y
+	select SERIAL_CORE_CONSOLE
+
 endmenu
 
 config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 9a548ac..a582831 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o
 obj-$(CONFIG_SERIAL_RP2)	+= rp2.o
 obj-$(CONFIG_SERIAL_FSL_LPUART)	+= fsl_lpuart.o
 obj-$(CONFIG_SERIAL_MEN_Z135)	+= men_z135_uart.o
+obj-$(CONFIG_SERIAL_STM32)	+= stm32-usart.o
 
 # GPIOLIB helpers for modem control lines
 obj-$(CONFIG_SERIAL_MCTRL_GPIO)	+= serial_mctrl_gpio.o
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
new file mode 100644
index 0000000..ef3c9fd
--- /dev/null
+++ b/drivers/tty/serial/stm32-usart.c
@@ -0,0 +1,695 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * Inspired by st-asc.c from STMicroelectronics (c)
+ */
+
+#if defined(CONFIG_SERIAL_STM32_USART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/serial_core.h>
+#include <linux/clk.h>
+
+#define DRIVER_NAME "stm32-usart"
+
+/* Register offsets */
+#define USART_SR		0x00
+#define USART_DR		0x04
+#define USART_BRR		0x08
+#define USART_CR1		0x0c
+#define USART_CR2		0x10
+#define USART_CR3		0x14
+#define USART_GTPR		0x18
+
+/* USART_SR */
+#define USART_SR_PE		BIT(0)
+#define USART_SR_FE		BIT(1)
+#define USART_SR_NF		BIT(2)
+#define USART_SR_ORE		BIT(3)
+#define USART_SR_IDLE		BIT(4)
+#define USART_SR_RXNE		BIT(5)
+#define USART_SR_TC		BIT(6)
+#define USART_SR_TXE		BIT(7)
+#define USART_SR_LBD		BIT(8)
+#define USART_SR_CTS		BIT(9)
+#define USART_SR_ERR_MASK	(USART_SR_LBD | USART_SR_ORE | \
+				 USART_SR_FE | USART_SR_PE)
+/* Dummy bits */
+#define USART_SR_DUMMY_RX	BIT(16)
+
+/* USART_DR */
+#define USART_DR_MASK		GENMASK(8, 0)
+
+/* USART_BRR */
+#define USART_BRR_DIV_F_MASK	GENMASK(3, 0)
+#define USART_BRR_DIV_M_MASK	GENMASK(15, 4)
+#define USART_BRR_DIV_M_SHIFT	4
+
+/* USART_CR1 */
+#define USART_CR1_SBK		BIT(0)
+#define USART_CR1_RWU		BIT(1)
+#define USART_CR1_RE		BIT(2)
+#define USART_CR1_TE		BIT(3)
+#define USART_CR1_IDLEIE	BIT(4)
+#define USART_CR1_RXNEIE	BIT(5)
+#define USART_CR1_TCIE		BIT(6)
+#define USART_CR1_TXEIE		BIT(7)
+#define USART_CR1_PEIE		BIT(8)
+#define USART_CR1_PS		BIT(9)
+#define USART_CR1_PCE		BIT(10)
+#define USART_CR1_WAKE		BIT(11)
+#define USART_CR1_M		BIT(12)
+#define USART_CR1_UE		BIT(13)
+#define USART_CR1_OVER8		BIT(15)
+#define USART_CR1_IE_MASK	GENMASK(8, 4)
+
+/* USART_CR2 */
+#define USART_CR2_ADD_MASK	GENMASK(3, 0)
+#define USART_CR2_LBDL		BIT(5)
+#define USART_CR2_LBDIE		BIT(6)
+#define USART_CR2_LBCL		BIT(8)
+#define USART_CR2_CPHA		BIT(9)
+#define USART_CR2_CPOL		BIT(10)
+#define USART_CR2_CLKEN		BIT(11)
+#define USART_CR2_STOP_2B	BIT(13)
+#define USART_CR2_STOP_MASK	GENMASK(13, 12)
+#define USART_CR2_LINEN		BIT(14)
+
+/* USART_CR3 */
+#define USART_CR3_EIE		BIT(0)
+#define USART_CR3_IREN		BIT(1)
+#define USART_CR3_IRLP		BIT(2)
+#define USART_CR3_HDSEL		BIT(3)
+#define USART_CR3_NACK		BIT(4)
+#define USART_CR3_SCEN		BIT(5)
+#define USART_CR3_DMAR		BIT(6)
+#define USART_CR3_DMAT		BIT(7)
+#define USART_CR3_RTSE		BIT(8)
+#define USART_CR3_CTSE		BIT(9)
+#define USART_CR3_CTSIE		BIT(10)
+#define USART_CR3_ONEBIT	BIT(11)
+
+/* USART_GTPR */
+#define USART_GTPR_PSC_MASK	GENMASK(7, 0)
+#define USART_GTPR_GT_MASK	GENMASK(15, 8)
+
+#define DRIVER_NAME "stm32-usart"
+#define STM32_SERIAL_NAME "ttyS"
+#define STM32_MAX_PORTS 6
+
+struct stm32_port {
+	struct uart_port port;
+	struct clk *clk;
+};
+
+static struct stm32_port stm32_ports[STM32_MAX_PORTS];
+static struct uart_driver stm32_usart_driver;
+
+static void stm32_stop_tx(struct uart_port *port);
+
+static void stm32_set_bits(struct uart_port *port, u32 reg, u32 bits)
+{
+	u32 val;
+
+	val = readl_relaxed(port->membase + reg);
+	val |= bits;
+	writel_relaxed(val, port->membase + reg);
+}
+
+static void stm32_clr_bits(struct uart_port *port, u32 reg, u32 bits)
+{
+	u32 val;
+
+	val = readl_relaxed(port->membase + reg);
+	val &= ~bits;
+	writel_relaxed(val, port->membase + reg);
+}
+
+static void stm32_receive_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned long c;
+	u32 sr;
+	char flag;
+
+	if (port->irq_wake)
+		pm_wakeup_event(tport->tty->dev, 0);
+
+	while ((sr = readl_relaxed(port->membase + USART_SR)) & USART_SR_RXNE) {
+		sr |= USART_SR_DUMMY_RX;
+		c = readl_relaxed(port->membase + USART_DR);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (sr & USART_SR_ERR_MASK) {
+			if (sr & USART_SR_LBD) {
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue;
+			} else if (sr & USART_SR_ORE) {
+				port->icount.overrun++;
+			} else if (sr & USART_SR_PE) {
+				port->icount.parity++;
+			} else if (sr & USART_SR_FE) {
+				port->icount.frame++;
+			}
+
+			sr &= port->read_status_mask;
+
+			if (sr & USART_SR_LBD)
+				flag = TTY_BREAK;
+			else if (sr & USART_SR_PE)
+				flag = TTY_PARITY;
+			else if (sr & USART_SR_FE)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(port, c))
+			continue;
+		uart_insert_char(port, sr, USART_SR_ORE, c, flag);
+	}
+
+	spin_unlock(&port->lock);
+	tty_flip_buffer_push(tport);
+	spin_lock(&port->lock);
+}
+
+static void stm32_transmit_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (port->x_char) {
+		writel_relaxed(port->x_char, port->membase + USART_DR);
+		port->x_char = 0;
+		port->icount.tx++;
+		return;
+	}
+
+	if (uart_tx_stopped(port)) {
+		stm32_stop_tx(port);
+		return;
+	}
+
+	if (uart_circ_empty(xmit)) {
+		stm32_stop_tx(port);
+		return;
+	}
+
+	writel_relaxed(xmit->buf[xmit->tail], port->membase + USART_DR);
+	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+	port->icount.tx++;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		stm32_stop_tx(port);
+}
+
+static irqreturn_t stm32_interrupt(int irq, void *ptr)
+{
+	struct uart_port *port = ptr;
+	u32 sr;
+
+	spin_lock(&port->lock);
+
+	sr = readl_relaxed(port->membase + USART_SR);
+
+	if (sr & USART_SR_RXNE)
+		stm32_receive_chars(port);
+
+	if (sr & USART_SR_TXE)
+		stm32_transmit_chars(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int stm32_tx_empty(struct uart_port *port)
+{
+	return readl_relaxed(port->membase + USART_SR) & USART_SR_TXE;
+}
+
+static void stm32_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/*
+	 * This routine is used for seting signals of: DTR, DCD, CTS/RTS
+	 * We use USART's hardware for CTS/RTS, so don't need any for that.
+	 * Some boards have DTR and DCD implemented using PIO pins,
+	 * code to do this should be hooked in here.
+	 */
+}
+
+static unsigned int stm32_get_mctrl(struct uart_port *port)
+{
+	/*
+	 * This routine is used for geting signals of: DTR, DCD, DSR, RI,
+	 * and CTS/RTS
+	 */
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/* There are probably characters waiting to be transmitted. */
+static void stm32_start_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (uart_circ_empty(xmit))
+		return;
+
+	stm32_set_bits(port, USART_CR1, USART_CR1_TXEIE | USART_CR1_TE);
+}
+
+/* Transmit stop */
+static void stm32_stop_tx(struct uart_port *port)
+{
+	stm32_clr_bits(port, USART_CR1, USART_CR1_TXEIE);
+}
+
+/* Receive stop */
+static void stm32_stop_rx(struct uart_port *port)
+{
+	stm32_clr_bits(port, USART_CR1, USART_CR1_RXNEIE);
+}
+
+/* Handle breaks - ignored by us */
+static void stm32_break_ctl(struct uart_port *port, int break_state)
+{
+	/* Nothing here yet .. */
+}
+
+static int stm32_startup(struct uart_port *port)
+{
+	const char *name = to_platform_device(port->dev)->name;
+	u32 val;
+
+	if (request_irq(port->irq, stm32_interrupt, IRQF_NO_SUSPEND,
+				name, port)) {
+		dev_err(port->dev, "cannot allocate irq %d\n", port->irq);
+		return -ENODEV;
+	}
+
+	val = USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
+	stm32_set_bits(port, USART_CR1, val);
+
+	return 0;
+}
+
+static void stm32_shutdown(struct uart_port *port)
+{
+	u32 val;
+
+	val = USART_CR1_TXEIE | USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
+	stm32_set_bits(port, USART_CR1, val);
+
+	free_irq(port->irq, port);
+}
+
+static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
+			    struct ktermios *old)
+{
+	unsigned int baud;
+	u32 usardiv, mantissa, fraction;
+	tcflag_t cflag;
+	u32 cr1, cr2, cr3;
+	unsigned long flags;
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+	cflag = termios->c_cflag;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Stop serial port and reset value */
+	writel_relaxed(0, port->membase + USART_CR1);
+
+	cr1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE | USART_CR1_RXNEIE;
+
+	if (cflag & CSTOPB)
+		cr2 = USART_CR2_STOP_2B;
+
+	if (cflag & PARENB) {
+		cr1 |= USART_CR1_PCE;
+		if ((cflag & CSIZE) == CS8)
+			cr1 |= USART_CR1_M;
+	}
+
+	if (cflag & PARODD)
+		cr1 |= USART_CR1_PS;
+
+	if (cflag & CRTSCTS)
+		cr3 = USART_CR3_RTSE | USART_CR3_CTSE;
+
+	usardiv = (port->uartclk * 25) / (baud * 4);
+	mantissa = (usardiv / 100) << USART_BRR_DIV_M_SHIFT;
+	fraction = DIV_ROUND_CLOSEST((usardiv % 100) * 16, 100);
+	if (fraction & ~USART_BRR_DIV_F_MASK) {
+		fraction = 0;
+		mantissa += (1 << USART_BRR_DIV_M_SHIFT);
+	}
+
+	writel_relaxed(mantissa | fraction, port->membase + USART_BRR);
+
+	uart_update_timeout(port, cflag, baud);
+
+	port->read_status_mask = USART_SR_ORE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= USART_SR_PE | USART_SR_FE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= USART_SR_LBD;
+
+	/* Characters to ignore */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask = USART_SR_PE | USART_SR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= USART_SR_LBD;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= USART_SR_ORE;
+	}
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= USART_SR_DUMMY_RX;
+
+	writel_relaxed(cr3, port->membase + USART_CR3);
+	writel_relaxed(cr2, port->membase + USART_CR2);
+	writel_relaxed(cr1, port->membase + USART_CR1);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *stm32_type(struct uart_port *port)
+{
+	return (port->type == PORT_STM32) ? DRIVER_NAME : NULL;
+}
+
+static void stm32_release_port(struct uart_port *port)
+{
+}
+
+static int stm32_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void stm32_config_port(struct uart_port *port, int flags)
+{
+	if ((flags & UART_CONFIG_TYPE))
+		port->type = PORT_STM32;
+}
+
+static int
+stm32_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* No user changeable parameters */
+	return -EINVAL;
+}
+
+static void stm32_pm(struct uart_port *port, unsigned int state,
+		unsigned int oldstate)
+{
+	struct stm32_port *stm32port = container_of(port,
+			struct stm32_port, port);
+	unsigned long flags = 0;
+
+	switch (state) {
+	case UART_PM_STATE_ON:
+		clk_prepare_enable(stm32port->clk);
+		break;
+	case UART_PM_STATE_OFF:
+		spin_lock_irqsave(&port->lock, flags);
+		stm32_clr_bits(port, USART_CR1, USART_CR1_UE);
+		spin_unlock_irqrestore(&port->lock, flags);
+		clk_disable_unprepare(stm32port->clk);
+		break;
+	}
+}
+
+static struct uart_ops stm32_uart_ops = {
+	.tx_empty	= stm32_tx_empty,
+	.set_mctrl	= stm32_set_mctrl,
+	.get_mctrl	= stm32_get_mctrl,
+	.start_tx	= stm32_start_tx,
+	.stop_tx	= stm32_stop_tx,
+	.stop_rx	= stm32_stop_rx,
+	.break_ctl	= stm32_break_ctl,
+	.startup	= stm32_startup,
+	.shutdown	= stm32_shutdown,
+	.set_termios	= stm32_set_termios,
+	.type		= stm32_type,
+	.release_port	= stm32_release_port,
+	.request_port	= stm32_request_port,
+	.config_port	= stm32_config_port,
+	.verify_port	= stm32_verify_port,
+	.pm		= stm32_pm,
+};
+
+static int stm32_init_port(struct stm32_port *stm32port,
+			  struct platform_device *pdev)
+{
+	struct uart_port *port = &stm32port->port;
+	struct resource *res;
+
+	port->iotype	= UPIO_MEM;
+	port->flags	= UPF_BOOT_AUTOCONF;
+	port->ops	= &stm32_uart_ops;
+	port->dev	= &pdev->dev;
+	port->irq	= platform_get_irq(pdev, 0);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	port->membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(port->membase))
+		return PTR_ERR(port->membase);
+	port->mapbase = res->start;
+
+	spin_lock_init(&port->lock);
+
+	stm32port->clk = devm_clk_get(&pdev->dev, NULL);
+
+	if (WARN_ON(IS_ERR(stm32port->clk)))
+		return -EINVAL;
+
+	/* ensure that clk rate is correct by enabling the clk */
+	clk_prepare_enable(stm32port->clk);
+	stm32port->port.uartclk = clk_get_rate(stm32port->clk);
+	WARN_ON(stm32port->port.uartclk == 0);
+	clk_disable_unprepare(stm32port->clk);
+
+	return 0;
+}
+
+static struct stm32_port *stm32_of_get_stm32_port(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int id;
+
+	if (!np)
+		return NULL;
+
+	id = of_alias_get_id(np, STM32_SERIAL_NAME);
+
+	if (id < 0)
+		id = 0;
+
+	if (WARN_ON(id >= STM32_MAX_PORTS))
+		return NULL;
+
+	stm32_ports[id].port.line = id;
+	return &stm32_ports[id];
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id stm32_match[] = {
+	{ .compatible = "st,stm32-usart", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, stm32_match);
+#endif
+
+static int stm32_serial_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct stm32_port *stm32port;
+
+	stm32port = stm32_of_get_stm32_port(pdev);
+	if (!stm32port)
+		return -ENODEV;
+
+	ret = stm32_init_port(stm32port, pdev);
+	if (ret)
+		return ret;
+
+	ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, &stm32port->port);
+
+	return 0;
+}
+
+static int stm32_serial_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	return uart_remove_one_port(&stm32_usart_driver, port);
+}
+
+
+#ifdef CONFIG_SERIAL_STM32_CONSOLE
+static void stm32_console_putchar(struct uart_port *port, int ch)
+{
+	while (!(readl_relaxed(port->membase + USART_SR) & USART_SR_TXE))
+		cpu_relax();
+
+	writel_relaxed(ch, port->membase + USART_DR);
+}
+
+static void stm32_console_write(struct console *co, const char *s, unsigned cnt)
+{
+	struct uart_port *port = &stm32_ports[co->index].port;
+	unsigned long flags;
+	u32 old_cr1, new_cr1;
+	int locked = 1;
+
+	if (oops_in_progress) {
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	} else {
+		locked = 1;
+		spin_lock_irqsave(&port->lock, flags);
+	}
+
+	/* Save and disable interrupts */
+	old_cr1 = readl_relaxed(port->membase + USART_CR1);
+	new_cr1 = old_cr1 & ~USART_CR1_IE_MASK;
+	writel_relaxed(new_cr1, port->membase + USART_CR1);
+
+	uart_console_write(port, s, cnt, stm32_console_putchar);
+
+	/* Restore interrupt state */
+	writel_relaxed(old_cr1, port->membase + USART_CR1);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int stm32_console_setup(struct console *co, char *options)
+{
+	struct stm32_port *stm32port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= STM32_MAX_PORTS)
+		return -ENODEV;
+
+	stm32port = &stm32_ports[co->index];
+
+	/*
+	 * This driver does not support early console initialization
+	 * (use ARM early printk support instead), so we only expect
+	 * this to be called during the uart port registration when the
+	 * driver gets probed and the port should be mapped at that point.
+	 */
+	if (stm32port->port.mapbase == 0 || stm32port->port.membase == NULL)
+		return -ENXIO;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&stm32port->port, co, baud, parity, bits, flow);
+}
+
+static struct console stm32_console = {
+	.name		= STM32_SERIAL_NAME,
+	.device		= uart_console_device,
+	.write		= stm32_console_write,
+	.setup		= stm32_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &stm32_usart_driver,
+};
+
+#define STM32_SERIAL_CONSOLE (&stm32_console)
+
+#else
+#define STM32_SERIAL_CONSOLE NULL
+#endif /* CONFIG_SERIAL_STM32_CONSOLE */
+
+static struct uart_driver stm32_usart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= STM32_SERIAL_NAME,
+	.major		= 0,
+	.minor		= 0,
+	.nr		= STM32_MAX_PORTS,
+	.cons		= STM32_SERIAL_CONSOLE,
+};
+
+static struct platform_driver stm32_serial_driver = {
+	.probe		= stm32_serial_probe,
+	.remove		= stm32_serial_remove,
+	.driver	= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(stm32_match),
+	},
+};
+
+static int __init usart_init(void)
+{
+	int ret;
+	static char banner[] __initdata =
+		KERN_INFO "STM32 USART driver initialized\n";
+
+	printk(banner);
+
+	ret = uart_register_driver(&stm32_usart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&stm32_serial_driver);
+	if (ret)
+		uart_unregister_driver(&stm32_usart_driver);
+
+	return ret;
+}
+
+static void __exit usart_exit(void)
+{
+	platform_driver_unregister(&stm32_serial_driver);
+	uart_unregister_driver(&stm32_usart_driver);
+}
+
+module_init(usart_init);
+module_exit(usart_exit);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_DESCRIPTION("STMicroelectronics STM32 serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index c172180..14ba8c4 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -248,4 +248,7 @@
 /* MESON */
 #define PORT_MESON	109
 
+/* STM32 USART */
+#define PORT_STM32	110
+
 #endif /* _UAPILINUX_SERIAL_CORE_H */
-- 
1.9.1

[PATCH 10/14] ARM: Add STM32 family machine

[Maxime Coquelin]

STMicrolectronics's STM32 series is a family of Cortex-M
microcontrollers. It is used in various applications, and
proposes a wide range of peripherals.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 Documentation/arm/stm32/overview.txt           | 32 ++++++++++++++++++++++++++
 Documentation/arm/stm32/stm32f429-overview.txt | 22 ++++++++++++++++++
 arch/arm/Kconfig                               | 22 ++++++++++++++++++
 arch/arm/Makefile                              |  1 +
 arch/arm/mach-stm32/Makefile                   |  1 +
 arch/arm/mach-stm32/Makefile.boot              |  0
 arch/arm/mach-stm32/board-dt.c                 | 19 +++++++++++++++
 7 files changed, 97 insertions(+)
 create mode 100644 Documentation/arm/stm32/overview.txt
 create mode 100644 Documentation/arm/stm32/stm32f429-overview.txt
 create mode 100644 arch/arm/mach-stm32/Makefile
 create mode 100644 arch/arm/mach-stm32/Makefile.boot
 create mode 100644 arch/arm/mach-stm32/board-dt.c

diff --git a/Documentation/arm/stm32/overview.txt b/Documentation/arm/stm32/overview.txt
new file mode 100644
index 0000000..d8bf6bb
--- /dev/null
+++ b/Documentation/arm/stm32/overview.txt
@@ -0,0 +1,32 @@
+			STM32 ARM Linux Overview
+			==========================
+
+Introduction
+------------
+
+  The STMicroelectronics family of Cortex-M based MCUs are supported by the
+  'STM32' platform of ARM Linux. Currently only the STM32F429 is supported.
+
+
+Configuration
+-------------
+
+  A generic configuration is provided for STM32 family, and can be used as the
+  default by
+	make stm32_defconfig
+
+Layout
+------
+
+  All the files for multiple machine families are located in the platform code
+  contained in arch/arm/mach-stm32
+
+  There is a generic board board-dt.c in the mach folder which support
+  Flattened Device Tree, which means, It works with any compatible board with
+  Device Trees.
+
+
+Document Author
+---------------
+
+  Maxime Coquelin <mcoquelin.stm32@gmail.com>
diff --git a/Documentation/arm/stm32/stm32f429-overview.txt b/Documentation/arm/stm32/stm32f429-overview.txt
new file mode 100644
index 0000000..5206822
--- /dev/null
+++ b/Documentation/arm/stm32/stm32f429-overview.txt
@@ -0,0 +1,22 @@
+			STM32F429 Overview
+			==================
+
+  Introduction
+  ------------
+	The STM32F429 is a Cortex-M4 MCU aimed at various applications.
+	It features:
+	- ARM Cortex-M4 up to 180MHz with FPU
+	- 2MB internal Flash Memory
+	- External memory support through FMC controller (PSRAM, SDRAM, NOR, NAND)
+	- I2C, SPI, SAI, CAN, USB OTG, Ethernet controllers
+	- LCD controller & Camera interface
+	- Cryptographic processor
+
+  Resources
+  ---------
+	Datasheet and reference manual are publicly available on ST website:
+	- http://www.st.com/web/en/catalog/mmc/FM141/SC1169/SS1577/LN1806?ecmp=stm32f429-439_pron_pr-ces2014_nov2013
+
+  Document Author
+  ---------------
+	Maxime Coquelin <mcoquelin.stm32@gmail.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 97d07ed..fd803a4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -774,6 +774,28 @@ config ARCH_OMAP1
 	help
 	  Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
 
+config ARCH_STM32
+	bool "STMicrolectronics STM32"
+	depends on !MMU
+	select ARCH_REQUIRE_GPIOLIB
+	select ARM_NVIC
+	select AUTO_ZRELADDR
+	select ARCH_HAS_RESET_CONTROLLER
+	select RESET_CONTROLLER
+	select PINCTRL
+	select PINCTRL_STM32
+	select CLKSRC_OF
+	select ARM_SYSTEM_TIMER
+	select COMMON_CLK
+	select CPU_V7M
+	select GENERIC_CLOCKEVENTS
+	select NO_DMA
+	select NO_IOPORT_MAP
+	select SPARSE_IRQ
+	select USE_OF
+	help
+	  Support for STMicorelectronics STM32 processors.
+
 endchoice
 
 menu "Multiple platform selection"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index c1785ee..7d00659 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -196,6 +196,7 @@ machine-$(CONFIG_ARCH_SHMOBILE) 	+= shmobile
 machine-$(CONFIG_ARCH_SIRF)		+= prima2
 machine-$(CONFIG_ARCH_SOCFPGA)		+= socfpga
 machine-$(CONFIG_ARCH_STI)		+= sti
+machine-$(CONFIG_ARCH_STM32)		+= stm32
 machine-$(CONFIG_ARCH_SUNXI)		+= sunxi
 machine-$(CONFIG_ARCH_TEGRA)		+= tegra
 machine-$(CONFIG_ARCH_U300)		+= u300
diff --git a/arch/arm/mach-stm32/Makefile b/arch/arm/mach-stm32/Makefile
new file mode 100644
index 0000000..bd0b7b5
--- /dev/null
+++ b/arch/arm/mach-stm32/Makefile
@@ -0,0 +1 @@
+obj-y += board-dt.o
diff --git a/arch/arm/mach-stm32/Makefile.boot b/arch/arm/mach-stm32/Makefile.boot
new file mode 100644
index 0000000..e69de29
diff --git a/arch/arm/mach-stm32/board-dt.c b/arch/arm/mach-stm32/board-dt.c
new file mode 100644
index 0000000..f2ad772
--- /dev/null
+++ b/arch/arm/mach-stm32/board-dt.c
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/kernel.h>
+#include <asm/v7m.h>
+#include <asm/mach/arch.h>
+
+static const char *const stm32_compat[] __initconst = {
+	"st,stm32f429",
+	NULL
+};
+
+DT_MACHINE_START(STM32DT, "STM32 (Device Tree Support)")
+	.dt_compat = stm32_compat,
+	.restart = armv7m_restart,
+MACHINE_END
-- 
1.9.1

[PATCH 11/14] ARM: dts: Add ARM System timer as clockevent in armv7m

[Maxime Coquelin]

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 arch/arm/boot/dts/armv7-m.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/armv7-m.dtsi b/arch/arm/boot/dts/armv7-m.dtsi
index 5a660d0..5b279d3 100644
--- a/arch/arm/boot/dts/armv7-m.dtsi
+++ b/arch/arm/boot/dts/armv7-m.dtsi
@@ -8,6 +8,13 @@
 		reg = <0xe000e100 0xc00>;
 	};
 
+	systick: system-timer {
+		compatible = "arm,armv7m-systick";
+		reg = <0xe000e010 0x10>;
+
+		status = "disabled";
+	};
+
 	soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
-- 
1.9.1

[PATCH 12/14] ARM: dts: Introduce STM32F429 MCU

[Maxime Coquelin]

The STMicrolectornics's STM32F419 MCU has the following main features:
 - Cortex-M4 core running up to @180MHz
 - 2MB internal flash, 256KBytes internal RAM
 - FMC controller to connect SDRAM, NOR and NAND memories
 - SD/MMC/SDIO support
 - Ethernet controller
 - USB OTFG FS & HS controllers
 - I2C, SPI, CAN busses support
 - Several 16 & 32 bits general purpose timers
 - Serial Audio interface
 - LCD controller

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 arch/arm/boot/dts/Makefile            |   1 +
 arch/arm/boot/dts/stm32f429-disco.dts |  41 +++++
 arch/arm/boot/dts/stm32f429.dtsi      | 279 ++++++++++++++++++++++++++++++++++
 3 files changed, 321 insertions(+)
 create mode 100644 arch/arm/boot/dts/stm32f429-disco.dts
 create mode 100644 arch/arm/boot/dts/stm32f429.dtsi

diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index 91bd5bd..d7da0ef 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -442,6 +442,7 @@ dtb-$(CONFIG_ARCH_STI)+= stih407-b2120.dtb \
 	stih416-b2000.dtb \
 	stih416-b2020.dtb \
 	stih416-b2020e.dtb
+dtb-$(CONFIG_ARCH_STM32)+= stm32f429-disco.dtb
 dtb-$(CONFIG_MACH_SUN4I) += \
 	sun4i-a10-a1000.dtb \
 	sun4i-a10-ba10-tvbox.dtb \
diff --git a/arch/arm/boot/dts/stm32f429-disco.dts b/arch/arm/boot/dts/stm32f429-disco.dts
new file mode 100644
index 0000000..0e79cc1
--- /dev/null
+++ b/arch/arm/boot/dts/stm32f429-disco.dts
@@ -0,0 +1,41 @@
+/dts-v1/;
+#include "stm32f429.dtsi"
+
+/ {
+	model = "STMicroelectronics's STM32F429i-DISCO board";
+	compatible = "st,stm32f429i-disco", "st,stm32f429";
+
+	chosen {
+		bootargs = "console=ttyS0,115200 root=/dev/ram rdinit=/linuxrc";
+		linux,stdout-path = &usart1;
+	};
+
+	memory {
+		reg = <0xd0000000 0x800000>;
+	};
+
+	aliases {
+		ttyS0 = &usart1;
+	};
+
+	soc {
+		usart1: usart@40011000 {
+			status = "okay";
+		};
+
+		leds {
+			compatible = "gpio-leds";
+			red {
+				#gpio-cells = <2>;
+				label = "Front Panel LED";
+				gpios = <&gpiog 14 0>;
+				linux,default-trigger = "heartbeat";
+			};
+			green {
+				#gpio-cells = <2>;
+				gpios = <&gpiog 13 0>;
+				default-state = "off";
+			};
+		};
+	};
+};
diff --git a/arch/arm/boot/dts/stm32f429.dtsi b/arch/arm/boot/dts/stm32f429.dtsi
new file mode 100644
index 0000000..71293c2
--- /dev/null
+++ b/arch/arm/boot/dts/stm32f429.dtsi
@@ -0,0 +1,279 @@
+/*
+ * Device tree for STM32F429
+ */
+#include "armv7-m.dtsi"
+#include <dt-bindings/pinctrl/pinctrl-stm32.h>
+
+/ {
+
+	aliases {
+		gpio0 = &gpioa;
+		gpio1 = &gpiob;
+		gpio2 = &gpioc;
+		gpio3 = &gpiod;
+		gpio4 = &gpioe;
+		gpio5 = &gpiof;
+		gpio6 = &gpiog;
+		gpio7 = &gpioh;
+		gpio8 = &gpioi;
+		gpio9 = &gpioj;
+		gpio10 = &gpiok;
+	};
+
+	clocks {
+		clk_sysclk: clk-sysclk {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <180000000>;
+		};
+
+		clk_hclk: clk-hclk {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <180000000>;
+		};
+
+		clk_pclk1: clk-pclk1 {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <45000000>;
+		};
+
+		clk_pclk2: clk-pclk2 {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <90000000>;
+		};
+
+		clk_pmtr1: clk-pmtr1 {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <90000000>;
+		};
+
+		clk_pmtr2: clk-pmtr2 {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <180000000>;
+		};
+
+		clk_systick: clk-systick {
+			compatible = "fixed-factor-clock";
+			clocks = <&clk_hclk>;
+			#clock-cells = <0>;
+			clock-div = <8>;
+			clock-mult = <1>;
+		};
+	};
+
+	systick: system-timer {
+		clocks = <&clk_systick>;
+
+		status = "okay";
+	};
+
+	soc {
+		reset_ahb1: reset@40023810 {
+			#reset-cells = <1>;
+			compatible = "st,stm32-reset";
+			reg = <0x40023810 0x4>;
+		};
+
+		reset_ahb2: reset@40023814 {
+			#reset-cells = <1>;
+			compatible = "st,stm32-reset";
+			reg = <0x40023814 0x4>;
+		};
+
+		reset_ahb3: reset@40023818 {
+			#reset-cells = <1>;
+			compatible = "st,stm32-reset";
+			reg = <0x40023818 0x4>;
+		};
+
+		reset_apb1: reset@40023820 {
+			#reset-cells = <1>;
+			compatible = "st,stm32-reset";
+			reg = <0x40023820 0x4>;
+		};
+
+		reset_apb2: reset@40023824 {
+			#reset-cells = <1>;
+			compatible = "st,stm32-reset";
+			reg = <0x40023824 0x4>;
+		};
+
+		pin-controller {
+			#address-cells = <1>;
+			#size-cells = <1>;
+			compatible = "st,stm32-pinctrl";
+			ranges = <0 0x40020000 0x3000>;
+
+			gpioa: gpio@40020000 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x0 0x400>;
+				resets = <&reset_ahb1 0>;
+				st,bank-name = "GPIOA";
+			};
+
+			gpiob: gpio@40020400 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x400 0x400>;
+				resets = <&reset_ahb1 1>;
+				st,bank-name = "GPIOB";
+			};
+
+			gpioc: gpio@40020800 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x800 0x400>;
+				resets = <&reset_ahb1 2>;
+				st,bank-name = "GPIOC";
+			};
+
+			gpiod: gpio@40020c00 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0xc00 0x400>;
+				resets = <&reset_ahb1 3>;
+				st,bank-name = "GPIOD";
+			};
+
+			gpioe: gpio@40021000 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x1000 0x400>;
+				resets = <&reset_ahb1 4>;
+				st,bank-name = "GPIOE";
+			};
+
+			gpiof: gpio@40021400 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x1400 0x400>;
+				resets = <&reset_ahb1 5>;
+				st,bank-name = "GPIOF";
+			};
+
+			gpiog: gpio@40021800 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x1800 0x400>;
+				resets = <&reset_ahb1 6>;
+				st,bank-name = "GPIOG";
+			};
+
+			gpioh: gpio@40021c00 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x1c00 0x400>;
+				resets = <&reset_ahb1 7>;
+				st,bank-name = "GPIOH";
+			};
+
+			gpioi: gpio@40022000 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x2000 0x400>;
+				resets = <&reset_ahb1 8>;
+				st,bank-name = "GPIOI";
+			};
+
+			gpioj: gpio@40022400 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x2400 0x400>;
+				resets = <&reset_ahb1 9>;
+				st,bank-name = "GPIOJ";
+			};
+
+			gpiok: gpio@40022800 {
+				gpio-controller;
+				#gpio-cells = <2>;
+				reg = <0x2800 0x400>;
+				resets = <&reset_ahb1 10>;
+				st,bank-name = "GPIOK";
+			};
+
+			usart1 {
+				pinctrl_usart1: usart1-0 {
+					st,pins {
+						tx = <&gpioa 9 ALT7 NO_PULL PUSH_PULL LOW_SPEED>;
+						rx = <&gpioa 10 ALT7 NO_PULL>;
+					};
+				};
+			};
+		};
+
+		timer2: timer@40000000 {
+			compatible = "st,stm32-timer";
+			reg = <0x40000000 0x400>;
+			interrupts = <28>;
+			resets = <&reset_apb1 0>;
+			clocks = <&clk_pmtr1>;
+
+			status = "disabled";
+		};
+
+		timer3: timer@40000400 {
+			compatible = "st,stm32-timer";
+			reg = <0x40000400 0x400>;
+			interrupts = <29>;
+			resets = <&reset_apb1 1>;
+			clocks = <&clk_pmtr1>;
+
+			status = "disabled";
+		};
+
+		timer4: timer@40000800 {
+			compatible = "st,stm32-timer";
+			reg = <0x40000800 0x400>;
+			interrupts = <30>;
+			resets = <&reset_apb1 2>;
+			clocks = <&clk_pmtr1>;
+
+			status = "disabled";
+		};
+
+		timer5: timer@40000c00 {
+			compatible = "st,stm32-timer";
+			reg = <0x40000c00 0x400>;
+			interrupts = <50>;
+			resets = <&reset_apb1 3>;
+			clocks = <&clk_pmtr1>;
+		};
+
+		timer6: timer@40001000 {
+			compatible = "st,stm32-timer";
+			reg = <0x40001000 0x400>;
+			interrupts = <55>;
+			resets = <&reset_apb1 4>;
+			clocks = <&clk_pmtr1>;
+
+			status = "disabled";
+		};
+
+		timer7: timer@40001400 {
+			compatible = "st,stm32-timer";
+			reg = <0x40001400 0x400>;
+			interrupts = <55>;
+			resets = <&reset_apb1 5>;
+			clocks = <&clk_pmtr1>;
+
+			status = "disabled";
+		};
+
+		usart1: usart@40011000 {
+			compatible = "st,stm32-usart";
+			reg = <0x40011000 0x400>;
+			interrupts = <37>;
+			clocks = <&clk_pclk2>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&pinctrl_usart1>;
+
+			status = "disabled";
+		};
+	};
+};
-- 
1.9.1

[PATCH 13/14] ARM: configs: Add STM32 defconfig

[Maxime Coquelin]

This patch adds a new config for STM32 MCUs.
STM32F429 Discovery board boots successfully with this config applied.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 arch/arm/configs/stm32_defconfig | 72 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 arch/arm/configs/stm32_defconfig

diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
new file mode 100644
index 0000000..3d7802a
--- /dev/null
+++ b/arch/arm/configs/stm32_defconfig
@@ -0,0 +1,72 @@
+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_LOG_BUF_SHIFT=16
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_INITRAMFS_SOURCE="./rootfs.cpio"
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+# CONFIG_UID16 is not set
+# CONFIG_BASE_FULL is not set
+# CONFIG_FUTEX is not set
+# CONFIG_EPOLL is not set
+# CONFIG_SIGNALFD is not set
+# CONFIG_EVENTFD is not set
+# CONFIG_AIO is not set
+CONFIG_EMBEDDED=y
+# CONFIG_VM_EVENT_COUNTERS is not set
+# CONFIG_SLUB_DEBUG is not set
+# CONFIG_LBDAF is not set
+# CONFIG_BLK_DEV_BSG is not set
+# CONFIG_IOSCHED_DEADLINE is not set
+# CONFIG_IOSCHED_CFQ is not set
+# CONFIG_MMU is not set
+CONFIG_ARCH_STM32=y
+CONFIG_SET_MEM_PARAM=y
+CONFIG_DRAM_BASE=0xd0000000
+CONFIG_FLASH_MEM_BASE=0x08000000
+CONFIG_FLASH_SIZE=0x00200000
+CONFIG_PREEMPT=y
+# CONFIG_ATAGS is not set
+CONFIG_ZBOOT_ROM_TEXT=0x0
+CONFIG_ZBOOT_ROM_BSS=0x0
+CONFIG_XIP_KERNEL=y
+CONFIG_XIP_PHYS_ADDR=0x08020000
+CONFIG_BINFMT_FLAT=y
+CONFIG_BINFMT_SHARED_FLAT=y
+# CONFIG_COREDUMP is not set
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+# CONFIG_FW_LOADER is not set
+# CONFIG_BLK_DEV is not set
+CONFIG_EEPROM_93CX6=y
+# CONFIG_INPUT is not set
+# CONFIG_SERIO is not set
+# CONFIG_VT is not set
+# CONFIG_UNIX98_PTYS is not set
+# CONFIG_LEGACY_PTYS is not set
+CONFIG_SERIAL_NONSTANDARD=y
+# CONFIG_DEVKMEM is not set
+CONFIG_SERIAL_STM32=y
+CONFIG_SERIAL_STM32_CONSOLE=y
+# CONFIG_HW_RANDOM is not set
+CONFIG_GPIO_SYSFS=y
+# CONFIG_HWMON is not set
+CONFIG_USB=y
+CONFIG_USB_DWC2=y
+CONFIG_NEW_LEDS=y
+CONFIG_LEDS_CLASS=y
+CONFIG_LEDS_GPIO=y
+CONFIG_LEDS_TRIGGERS=y
+CONFIG_LEDS_TRIGGER_HEARTBEAT=y
+# CONFIG_IOMMU_SUPPORT is not set
+# CONFIG_FILE_LOCKING is not set
+# CONFIG_DNOTIFY is not set
+# CONFIG_INOTIFY_USER is not set
+CONFIG_PRINTK_TIME=y
+CONFIG_DEBUG_INFO=y
+# CONFIG_ENABLE_WARN_DEPRECATED is not set
+# CONFIG_ENABLE_MUST_CHECK is not set
+CONFIG_MAGIC_SYSRQ=y
+# CONFIG_SCHED_DEBUG is not set
+# CONFIG_DEBUG_BUGVERBOSE is not set
+# CONFIG_FTRACE is not set
+CONFIG_CRC_ITU_T=y
+CONFIG_CRC7=y
-- 
1.9.1

[PATCH 14/14] MAINTAINERS: Add entry for STM32 MCUs

[Maxime Coquelin]

Add a MAINTAINER entry covering all STM32 machine and drivers files.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 MAINTAINERS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index d66a97d..78f47ac 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1448,6 +1448,13 @@ F:	drivers/usb/host/ehci-st.c
 F:	drivers/usb/host/ohci-st.c
 F:	drivers/ata/ahci_st.c
 
+ARM/STM32 ARCHITECTURE
+M:	Maxime Coquelin <mcoquelin.stm32@gmail.com>
+L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+S:	Maintained
+N:	stm32
+F:	drivers/clocksource/arm_system_timer.c
+
 ARM/TECHNOLOGIC SYSTEMS TS7250 MACHINE SUPPORT
 M:	Lennert Buytenhek <kernel@wantstofly.org>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
-- 
1.9.1

Re: [PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Geert Uytterhoeven]

On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:
> From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
> interrupts. So the number of entries in vectors table is 256.
>
> This patch adds the missing entries, and change the alignement, so that
> vector_table remains naturally aligned.

Shouldn't this depend on ARCH_STM32, or some other M4 or M7 specific
Kconfig option, to avoid wasting the space on other CPUs?

>
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> ---
>  arch/arm/kernel/entry-v7m.S | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/kernel/entry-v7m.S b/arch/arm/kernel/entry-v7m.S
> index 8944f49..29a461b 100644
> --- a/arch/arm/kernel/entry-v7m.S
> +++ b/arch/arm/kernel/entry-v7m.S
> @@ -117,9 +117,9 @@ ENTRY(__switch_to)
>  ENDPROC(__switch_to)
>
>         .data
> -       .align  8
> +       .align  10
>  /*
> - * Vector table (64 words => 256 bytes natural alignment)
> + * Vector table (256 words => 1024 bytes alignment)
>   */
>  ENTRY(vector_table)
>         .long   0                       @ 0 - Reset stack pointer
> @@ -138,6 +138,6 @@ ENTRY(vector_table)
>         .long   __invalid_entry         @ 13 - Reserved
>         .long   __pendsv_entry          @ 14 - PendSV
>         .long   __invalid_entry         @ 15 - SysTick
> -       .rept   64 - 16
> -       .long   __irq_entry             @ 16..64 - External Interrupts
> +       .rept   256 - 16
> +       .long   __irq_entry             @ 16..256 - External Interrupts
>         .endr
> --
> 1.9.1

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 08/14] pinctrl: Add pinctrl driver for STM32 MCUs

[Geert Uytterhoeven]

On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -125,6 +125,15 @@ config PINCTRL_ST
>         select PINCONF
>         select GPIOLIB_IRQCHIP
>
> +config PINCTRL_STM32
> +       bool "STMicroelectronics STM32 pinctrl driver"
> +       depends on OF

depends on ARCH_STM32 || COMPILE_TEST

> +       select PINMUX
> +       select PINCONF
> +       select GPIOLIB_IRQCHIP
> +       help
> +         This selects the device tree based generic pinctrl driver for STM32.
> +
>  config PINCTRL_TEGRA
>         bool
>         select PINMUX

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Maxime Coquelin]

Hi Geert,

2015-02-12 21:34 GMT+01:00 Geert Uytterhoeven <geert@linux-m68k.org>:
> On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
>> From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
>> interrupts. So the number of entries in vectors table is 256.
>>
>> This patch adds the missing entries, and change the alignement, so that
>> vector_table remains naturally aligned.
>
> Shouldn't this depend on ARCH_STM32, or some other M4 or M7 specific
> Kconfig option, to avoid wasting the space on other CPUs?

Actually, the STM32F429 has 90 interrupts, so it would need 106
entries in the vector table.
The maximum of supported interrupts is not only for Cortex-M4 and M7,
this is also true for Cortex-M3.

I see two possibilities:
 1 - We declare the vector table for the maximum supported number of
IRQs, as this patch does.
        - Pro: it will be functionnal with all Cortex-M MCUs
        - Con: Waste of less than 1KB for memory
 2 - We introduce a config flag that provides the number of interrupts
        - Pro: No more memory waste
        - Con: Need to declare a per MCU model config flag.

Then, regarding the natural alignment, is there a way to ensure it
depending on the value of a config flag?
Or we should keep it at the maximum value possible?

Any feedback will be appreciated, especially from Uwe who maintains
the efm32 machine.

Kind regards,
Maxime

Re: [PATCH 08/14] pinctrl: Add pinctrl driver for STM32 MCUs

[Maxime Coquelin]

2015-02-12 21:37 GMT+01:00 Geert Uytterhoeven <geert@linux-m68k.org>:
> On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
>> --- a/drivers/pinctrl/Kconfig
>> +++ b/drivers/pinctrl/Kconfig
>> @@ -125,6 +125,15 @@ config PINCTRL_ST
>>         select PINCONF
>>         select GPIOLIB_IRQCHIP
>>
>> +config PINCTRL_STM32
>> +       bool "STMicroelectronics STM32 pinctrl driver"
>> +       depends on OF
>
> depends on ARCH_STM32 || COMPILE_TEST

Ok, I agree.

It will be part of the v2.

Thanks,
Maxime

Re: [PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Uwe Kleine-König]

On Fri, Feb 13, 2015 at 09:42:46AM +0100, Maxime Coquelin wrote:
> Hi Geert,
> 
> 2015-02-12 21:34 GMT+01:00 Geert Uytterhoeven <geert@linux-m68k.org>:
> > On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
> > <mcoquelin.stm32@gmail.com> wrote:
> >> From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
> >> interrupts. So the number of entries in vectors table is 256.
> >>
> >> This patch adds the missing entries, and change the alignement, so that
> >> vector_table remains naturally aligned.
> >
> > Shouldn't this depend on ARCH_STM32, or some other M4 or M7 specific
> > Kconfig option, to avoid wasting the space on other CPUs?
> 
> Actually, the STM32F429 has 90 interrupts, so it would need 106
> entries in the vector table.
> The maximum of supported interrupts is not only for Cortex-M4 and M7,
> this is also true for Cortex-M3.
> 
> I see two possibilities:
>  1 - We declare the vector table for the maximum supported number of
> IRQs, as this patch does.
>         - Pro: it will be functionnal with all Cortex-M MCUs
>         - Con: Waste of less than 1KB for memory
>  2 - We introduce a config flag that provides the number of interrupts
>         - Pro: No more memory waste
>         - Con: Need to declare a per MCU model config flag.
I'd vote for 2, something like:

	config CPUV7M_NUM_IRQ
		int
		default 90 if STM32F429
		default 38 if EFM32GG
		default 240

then there is a working default and platforms being short on memory can
configure as appropriate. (The only down side is that if we create
multi-platfrom images at some time in the future either all or none of
the supported platforms must provide a value here.)
 
> Then, regarding the natural alignment, is there a way to ensure it
> depending on the value of a config flag?
The exact wording in ARMARMv7-M is:

	The Vector table must be naturally aligned to a power of two
	whose alignment value is greater than or equal
	to (Number of Exceptions supported x 4), with a minimum
	alignment of 128 bytes.

> Or we should keep it at the maximum value possible?
So we need:

	.align x

with x being max(7, ceil(log((CPUV7M_NUM_IRQ + 16) * 4, 2))). So the
alignment needed is between 7 and 10.

If the assembler supports an expression here I'd use that. But before
adding strange hacks to generate the right value there better go for a
static value like:

	/* The vector table must be naturally aligned */
	#if CONFIG_CPUV7M_NUM_IRQ <= 112
	.align 9 /* log2((112 + 16) * 4) */
	#else
	.align 10
	#endif

Further steps would be:

	CONFIG_CPUV7M_NUM_IRQ <= 48 -> .align 8
	CONFIG_CPUV7M_NUM_IRQ <= 16 -> .align 7

Probably it's not worth to add the respective #ifdefs here.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

Re: [PATCH 12/14] ARM: dts: Introduce STM32F429 MCU

[Philipp Zabel]

Hi Maxime,

Am Donnerstag, den 12.02.2015, 18:46 +0100 schrieb Maxime Coquelin:
[...]
> +	soc {
> +		reset_ahb1: reset@40023810 {
> +			#reset-cells = <1>;
> +			compatible = "st,stm32-reset";
> +			reg = <0x40023810 0x4>;
> +		};
> +
> +		reset_ahb2: reset@40023814 {
> +			#reset-cells = <1>;
> +			compatible = "st,stm32-reset";
> +			reg = <0x40023814 0x4>;
> +		};
> +
> +		reset_ahb3: reset@40023818 {
> +			#reset-cells = <1>;
> +			compatible = "st,stm32-reset";
> +			reg = <0x40023818 0x4>;
> +		};
> +
> +		reset_apb1: reset@40023820 {
> +			#reset-cells = <1>;
> +			compatible = "st,stm32-reset";
> +			reg = <0x40023820 0x4>;
> +		};
> +
> +		reset_apb2: reset@40023824 {
> +			#reset-cells = <1>;
> +			compatible = "st,stm32-reset";
> +			reg = <0x40023824 0x4>;
> +		};

These are mostly consecutive, single registers. I wonder if these are
part of the same IP block and thus should be grouped together into the
same reset controller node?

regards
Philipp

Re: [PATCH 04/14] reset: Add reset_controller_of_init() function

[Philipp Zabel]

Hi Maxime,

Am Donnerstag, den 12.02.2015, 18:45 +0100 schrieb Maxime Coquelin:
> Some platforms need to initialize the reset controller before the timers.
> 
> This patch introduces a reset_controller_of_init() function that can be
> called before the timers intialization.
> 
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> ---
>  drivers/reset/core.c              | 20 ++++++++++++++++++++
>  include/asm-generic/vmlinux.lds.h |  4 +++-
>  include/linux/reset-controller.h  |  6 ++++++
>  3 files changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index 7955e00..18ee579 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -86,6 +86,26 @@ void reset_controller_unregister(struct reset_controller_dev *rcdev)
>  }
>  EXPORT_SYMBOL_GPL(reset_controller_unregister);
>  
> +extern struct of_device_id __reset_ctrl_of_table[];
> +
> +static const struct of_device_id __reset_ctrl_of_table_sentinel
> +	__used __section(__reset_ctrl_of_table_end);
> +
> +void __init reset_controller_of_init(void)

The patch looks fine to me, but this function is missing a kerneldoc
comment.

> +{
> +	struct device_node *np;
> +	const struct of_device_id *match;
> +	of_init_fn_1 init_func;
> +
> +	for_each_matching_node_and_match(np, __reset_ctrl_of_table, &match) {
> +		if (!of_device_is_available(np))
> +			continue;
> +
> +		init_func = match->data;
> +		init_func(np);
> +	}
> +}
> +
>  /**
>   * reset_control_reset - reset the controlled device
>   * @rstc: reset controller

regards
Philipp

Re: [PATCH 12/14] ARM: dts: Introduce STM32F429 MCU

[Maxime Coquelin]

Hi Philipp,

2015-02-13 12:47 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> Hi Maxime,
>
> Am Donnerstag, den 12.02.2015, 18:46 +0100 schrieb Maxime Coquelin:
> [...]
>> +     soc {
>> +             reset_ahb1: reset@40023810 {
>> +                     #reset-cells = <1>;
>> +                     compatible = "st,stm32-reset";
>> +                     reg = <0x40023810 0x4>;
>> +             };
>> +
>> +             reset_ahb2: reset@40023814 {
>> +                     #reset-cells = <1>;
>> +                     compatible = "st,stm32-reset";
>> +                     reg = <0x40023814 0x4>;
>> +             };
>> +
>> +             reset_ahb3: reset@40023818 {
>> +                     #reset-cells = <1>;
>> +                     compatible = "st,stm32-reset";
>> +                     reg = <0x40023818 0x4>;
>> +             };
>> +
>> +             reset_apb1: reset@40023820 {
>> +                     #reset-cells = <1>;
>> +                     compatible = "st,stm32-reset";
>> +                     reg = <0x40023820 0x4>;
>> +             };
>> +
>> +             reset_apb2: reset@40023824 {
>> +                     #reset-cells = <1>;
>> +                     compatible = "st,stm32-reset";
>> +                     reg = <0x40023824 0x4>;
>> +             };
>
> These are mostly consecutive, single registers. I wonder if these are
> part of the same IP block and thus should be grouped together into the
> same reset controller node?

What I could to is to have two instances. One for AHB and one for APB domain.
Doing this, I will have one instance per domain, and only consecutive registers.
Is it fine for you?

Thanks,
Maxime

>
> regards
> Philipp
>

Re: [PATCH 04/14] reset: Add reset_controller_of_init() function

[Maxime Coquelin]

Hi Philipp,

2015-02-13 12:49 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> Hi Maxime,
>
> Am Donnerstag, den 12.02.2015, 18:45 +0100 schrieb Maxime Coquelin:
>> Some platforms need to initialize the reset controller before the timers.
>>
>> This patch introduces a reset_controller_of_init() function that can be
>> called before the timers intialization.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>> ---
>>  drivers/reset/core.c              | 20 ++++++++++++++++++++
>>  include/asm-generic/vmlinux.lds.h |  4 +++-
>>  include/linux/reset-controller.h  |  6 ++++++
>>  3 files changed, 29 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
>> index 7955e00..18ee579 100644
>> --- a/drivers/reset/core.c
>> +++ b/drivers/reset/core.c
>> @@ -86,6 +86,26 @@ void reset_controller_unregister(struct reset_controller_dev *rcdev)
>>  }
>>  EXPORT_SYMBOL_GPL(reset_controller_unregister);
>>
>> +extern struct of_device_id __reset_ctrl_of_table[];
>> +
>> +static const struct of_device_id __reset_ctrl_of_table_sentinel
>> +     __used __section(__reset_ctrl_of_table_end);
>> +
>> +void __init reset_controller_of_init(void)
>
> The patch looks fine to me, but this function is missing a kerneldoc
> comment.

Right! It will be fixed in the v2.

Thanks,
Maxime

Re: [PATCH 12/14] ARM: dts: Introduce STM32F429 MCU

[Philipp Zabel]

Hi Maxime,

Am Freitag, den 13.02.2015, 16:59 +0100 schrieb Maxime Coquelin:
> Hi Philipp,
> 
> 2015-02-13 12:47 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> > Hi Maxime,
> >
> > Am Donnerstag, den 12.02.2015, 18:46 +0100 schrieb Maxime Coquelin:
> > [...]
> >> +     soc {
> >> +             reset_ahb1: reset@40023810 {
> >> +                     #reset-cells = <1>;
> >> +                     compatible = "st,stm32-reset";
> >> +                     reg = <0x40023810 0x4>;
> >> +             };
> >> +
> >> +             reset_ahb2: reset@40023814 {
> >> +                     #reset-cells = <1>;
> >> +                     compatible = "st,stm32-reset";
> >> +                     reg = <0x40023814 0x4>;
> >> +             };
> >> +
> >> +             reset_ahb3: reset@40023818 {
> >> +                     #reset-cells = <1>;
> >> +                     compatible = "st,stm32-reset";
> >> +                     reg = <0x40023818 0x4>;
> >> +             };
> >> +
> >> +             reset_apb1: reset@40023820 {
> >> +                     #reset-cells = <1>;
> >> +                     compatible = "st,stm32-reset";
> >> +                     reg = <0x40023820 0x4>;
> >> +             };
> >> +
> >> +             reset_apb2: reset@40023824 {
> >> +                     #reset-cells = <1>;
> >> +                     compatible = "st,stm32-reset";
> >> +                     reg = <0x40023824 0x4>;
> >> +             };
> >
> > These are mostly consecutive, single registers. I wonder if these are
> > part of the same IP block and thus should be grouped together into the
> > same reset controller node?
> 
> What I could to is to have two instances. One for AHB and one for APB domain.
> Doing this, I will have one instance per domain, and only consecutive registers.
> Is it fine for you?

Looking at
http://www.st.com/web/en/resource/technical/document/reference_manual/DM00031020.pdf
Table 34 (RCC register map and reset values), I'd say there is a single
"Reset and Clock Control" device at 0x40023800 - 0x40023884:

	soc {
		rcc: rcc@40023800 {
			#clock-cells = <1>;
			#reset-cells = <1>;
			compatible = "st,stm32-rcc";
			reg = <0x40023800 0x84>;
		};

		...

If you really want to describe the reset controller parts (offsets +0x10
to +0x24) in a separate node, I won't argue against it too long,
although this is a somewhat arbitrary decision.

In any case, the whole register at offset +0x1c is reserved, so there is
no reason to split the reset controller. It is ok to have unused ranges
as is already the case with reserved bits inside the used registers.

regards
Philipp

Re: [PATCH 12/14] ARM: dts: Introduce STM32F429 MCU

[Maxime Coquelin]

2015-02-13 17:25 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> Hi Maxime,
>
> Am Freitag, den 13.02.2015, 16:59 +0100 schrieb Maxime Coquelin:
>> Hi Philipp,
>>
>> 2015-02-13 12:47 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
>> > Hi Maxime,
>> >
>> > Am Donnerstag, den 12.02.2015, 18:46 +0100 schrieb Maxime Coquelin:
>> > [...]
>> >> +     soc {
>> >> +             reset_ahb1: reset@40023810 {
>> >> +                     #reset-cells = <1>;
>> >> +                     compatible = "st,stm32-reset";
>> >> +                     reg = <0x40023810 0x4>;
>> >> +             };
>> >> +
>> >> +             reset_ahb2: reset@40023814 {
>> >> +                     #reset-cells = <1>;
>> >> +                     compatible = "st,stm32-reset";
>> >> +                     reg = <0x40023814 0x4>;
>> >> +             };
>> >> +
>> >> +             reset_ahb3: reset@40023818 {
>> >> +                     #reset-cells = <1>;
>> >> +                     compatible = "st,stm32-reset";
>> >> +                     reg = <0x40023818 0x4>;
>> >> +             };
>> >> +
>> >> +             reset_apb1: reset@40023820 {
>> >> +                     #reset-cells = <1>;
>> >> +                     compatible = "st,stm32-reset";
>> >> +                     reg = <0x40023820 0x4>;
>> >> +             };
>> >> +
>> >> +             reset_apb2: reset@40023824 {
>> >> +                     #reset-cells = <1>;
>> >> +                     compatible = "st,stm32-reset";
>> >> +                     reg = <0x40023824 0x4>;
>> >> +             };
>> >
>> > These are mostly consecutive, single registers. I wonder if these are
>> > part of the same IP block and thus should be grouped together into the
>> > same reset controller node?
>>
>> What I could to is to have two instances. One for AHB and one for APB domain.
>> Doing this, I will have one instance per domain, and only consecutive registers.
>> Is it fine for you?
>
> Looking at
> http://www.st.com/web/en/resource/technical/document/reference_manual/DM00031020.pdf
> Table 34 (RCC register map and reset values), I'd say there is a single
> "Reset and Clock Control" device at 0x40023800 - 0x40023884:
>
>         soc {
>                 rcc: rcc@40023800 {
>                         #clock-cells = <1>;
>                         #reset-cells = <1>;
>                         compatible = "st,stm32-rcc";
>                         reg = <0x40023800 0x84>;
>                 };
>
>                 ...
>
> If you really want to describe the reset controller parts (offsets +0x10
> to +0x24) in a separate node, I won't argue against it too long,
> although this is a somewhat arbitrary decision.
>
> In any case, the whole register at offset +0x1c is reserved, so there is
> no reason to split the reset controller. It is ok to have unused ranges
> as is already the case with reserved bits inside the used registers.

Ok. I understand your point.
But it will be more difficult at usage, because the node referencing
the fourth reset bit of apb2 register will have to pass 164 as
parameter.
It is error prone IMHO.

Other solution would be to add some defines for each reset line in the
DT-Bindings, as we do today for STi platform.
But it is giving an unneeded constraint between DT and reset trees.

Br,
Maxime

>
> regards
> Philipp
>

Re: [PATCH 12/14] ARM: dts: Introduce STM32F429 MCU

[Philipp Zabel]

Am Freitag, den 13.02.2015, 17:41 +0100 schrieb Maxime Coquelin:
> 2015-02-13 17:25 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> > Hi Maxime,
> >
> > Am Freitag, den 13.02.2015, 16:59 +0100 schrieb Maxime Coquelin:
> >> Hi Philipp,
> >>
> >> 2015-02-13 12:47 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> >> > Hi Maxime,
> >> >
> >> > Am Donnerstag, den 12.02.2015, 18:46 +0100 schrieb Maxime Coquelin:
> >> > [...]
> >> >> +     soc {
> >> >> +             reset_ahb1: reset@40023810 {
> >> >> +                     #reset-cells = <1>;
> >> >> +                     compatible = "st,stm32-reset";
> >> >> +                     reg = <0x40023810 0x4>;
> >> >> +             };
> >> >> +
> >> >> +             reset_ahb2: reset@40023814 {
> >> >> +                     #reset-cells = <1>;
> >> >> +                     compatible = "st,stm32-reset";
> >> >> +                     reg = <0x40023814 0x4>;
> >> >> +             };
> >> >> +
> >> >> +             reset_ahb3: reset@40023818 {
> >> >> +                     #reset-cells = <1>;
> >> >> +                     compatible = "st,stm32-reset";
> >> >> +                     reg = <0x40023818 0x4>;
> >> >> +             };
> >> >> +
> >> >> +             reset_apb1: reset@40023820 {
> >> >> +                     #reset-cells = <1>;
> >> >> +                     compatible = "st,stm32-reset";
> >> >> +                     reg = <0x40023820 0x4>;
> >> >> +             };
> >> >> +
> >> >> +             reset_apb2: reset@40023824 {
> >> >> +                     #reset-cells = <1>;
> >> >> +                     compatible = "st,stm32-reset";
> >> >> +                     reg = <0x40023824 0x4>;
> >> >> +             };
> >> >
> >> > These are mostly consecutive, single registers. I wonder if these are
> >> > part of the same IP block and thus should be grouped together into the
> >> > same reset controller node?
> >>
> >> What I could to is to have two instances. One for AHB and one for APB domain.
> >> Doing this, I will have one instance per domain, and only consecutive registers.
> >> Is it fine for you?
> >
> > Looking at
> > http://www.st.com/web/en/resource/technical/document/reference_manual/DM00031020.pdf
> > Table 34 (RCC register map and reset values), I'd say there is a single
> > "Reset and Clock Control" device at 0x40023800 - 0x40023884:
> >
> >         soc {
> >                 rcc: rcc@40023800 {
> >                         #clock-cells = <1>;
> >                         #reset-cells = <1>;
> >                         compatible = "st,stm32-rcc";
> >                         reg = <0x40023800 0x84>;
> >                 };
> >
> >                 ...
> >
> > If you really want to describe the reset controller parts (offsets +0x10
> > to +0x24) in a separate node, I won't argue against it too long,
> > although this is a somewhat arbitrary decision.
> >
> > In any case, the whole register at offset +0x1c is reserved, so there is
> > no reason to split the reset controller. It is ok to have unused ranges
> > as is already the case with reserved bits inside the used registers.
> 
> Ok. I understand your point.
> But it will be more difficult at usage, because the node referencing
> the fourth reset bit of apb2 register will have to pass 164 as
> parameter.
> It is error prone IMHO.
>
> Other solution would be to add some defines for each reset line in the
> DT-Bindings, as we do today for STi platform.
> But it is giving an unneeded constraint between DT and reset trees.

That is a bit unfortunate, but providing the named constants in
include/dt-bindings/reset/ makes for a much better readable device tree,
so I'd prefer that solution, even if it means having to coordinate pull
requests.

regards
Philipp

Re: [PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Maxime Coquelin]

2015-02-13 11:00 GMT+01:00 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:
> On Fri, Feb 13, 2015 at 09:42:46AM +0100, Maxime Coquelin wrote:
>> Hi Geert,
>>
>> 2015-02-12 21:34 GMT+01:00 Geert Uytterhoeven <geert@linux-m68k.org>:
>> > On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
>> > <mcoquelin.stm32@gmail.com> wrote:
>> >> From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
>> >> interrupts. So the number of entries in vectors table is 256.
>> >>
>> >> This patch adds the missing entries, and change the alignement, so that
>> >> vector_table remains naturally aligned.
>> >
>> > Shouldn't this depend on ARCH_STM32, or some other M4 or M7 specific
>> > Kconfig option, to avoid wasting the space on other CPUs?
>>
>> Actually, the STM32F429 has 90 interrupts, so it would need 106
>> entries in the vector table.
>> The maximum of supported interrupts is not only for Cortex-M4 and M7,
>> this is also true for Cortex-M3.
>>
>> I see two possibilities:
>>  1 - We declare the vector table for the maximum supported number of
>> IRQs, as this patch does.
>>         - Pro: it will be functionnal with all Cortex-M MCUs
>>         - Con: Waste of less than 1KB for memory
>>  2 - We introduce a config flag that provides the number of interrupts
>>         - Pro: No more memory waste
>>         - Con: Need to declare a per MCU model config flag.
> I'd vote for 2, something like:
>
>         config CPUV7M_NUM_IRQ
>                 int
>                 default 90 if STM32F429
>                 default 38 if EFM32GG
>                 default 240
>
> then there is a working default and platforms being short on memory can
> configure as appropriate. (The only down side is that if we create
> multi-platfrom images at some time in the future either all or none of
> the supported platforms must provide a value here.)

Ok, I'm fine doing this way.
I will implement this in the v2 if Russel is fine with the proposal too.

>
>> Then, regarding the natural alignment, is there a way to ensure it
>> depending on the value of a config flag?
> The exact wording in ARMARMv7-M is:
>
>         The Vector table must be naturally aligned to a power of two
>         whose alignment value is greater than or equal
>         to (Number of Exceptions supported x 4), with a minimum
>         alignment of 128 bytes.
>
>> Or we should keep it at the maximum value possible?
> So we need:
>
>         .align x
>
> with x being max(7, ceil(log((CPUV7M_NUM_IRQ + 16) * 4, 2))). So the
> alignment needed is between 7 and 10.
>
> If the assembler supports an expression here I'd use that. But before
> adding strange hacks to generate the right value there better go for a
> static value like:
>
>         /* The vector table must be naturally aligned */
>         #if CONFIG_CPUV7M_NUM_IRQ <= 112
>         .align 9 /* log2((112 + 16) * 4) */
>         #else
>         .align 10
>         #endif
>
> Further steps would be:
>
>         CONFIG_CPUV7M_NUM_IRQ <= 48 -> .align 8
>         CONFIG_CPUV7M_NUM_IRQ <= 16 -> .align 7
>
> Probably it's not worth to add the respective #ifdefs here.

I will go for the  #ifdefs.

Thanks,
Maxime

>
> Best regards
> Uwe
>
> --
> Pengutronix e.K.                           | Uwe Kleine-König            |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |

Re: [PATCH 12/14] ARM: dts: Introduce STM32F429 MCU

[Maxime Coquelin]

Hi Philipp,

2015-02-13 20:18 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
> Am Freitag, den 13.02.2015, 17:41 +0100 schrieb Maxime Coquelin:
>> 2015-02-13 17:25 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
>> > Hi Maxime,
>> >
>> > Am Freitag, den 13.02.2015, 16:59 +0100 schrieb Maxime Coquelin:
>> >> Hi Philipp,
>> >>
>> >> 2015-02-13 12:47 GMT+01:00 Philipp Zabel <p.zabel@pengutronix.de>:
>> >> > Hi Maxime,
>> >> >
>> >> > Am Donnerstag, den 12.02.2015, 18:46 +0100 schrieb Maxime Coquelin:
>> >> > [...]
>> >> >> +     soc {
>> >> >> +             reset_ahb1: reset@40023810 {
>> >> >> +                     #reset-cells = <1>;
>> >> >> +                     compatible = "st,stm32-reset";
>> >> >> +                     reg = <0x40023810 0x4>;
>> >> >> +             };
>> >> >> +
>> >> >> +             reset_ahb2: reset@40023814 {
>> >> >> +                     #reset-cells = <1>;
>> >> >> +                     compatible = "st,stm32-reset";
>> >> >> +                     reg = <0x40023814 0x4>;
>> >> >> +             };
>> >> >> +
>> >> >> +             reset_ahb3: reset@40023818 {
>> >> >> +                     #reset-cells = <1>;
>> >> >> +                     compatible = "st,stm32-reset";
>> >> >> +                     reg = <0x40023818 0x4>;
>> >> >> +             };
>> >> >> +
>> >> >> +             reset_apb1: reset@40023820 {
>> >> >> +                     #reset-cells = <1>;
>> >> >> +                     compatible = "st,stm32-reset";
>> >> >> +                     reg = <0x40023820 0x4>;
>> >> >> +             };
>> >> >> +
>> >> >> +             reset_apb2: reset@40023824 {
>> >> >> +                     #reset-cells = <1>;
>> >> >> +                     compatible = "st,stm32-reset";
>> >> >> +                     reg = <0x40023824 0x4>;
>> >> >> +             };
>> >> >
>> >> > These are mostly consecutive, single registers. I wonder if these are
>> >> > part of the same IP block and thus should be grouped together into the
>> >> > same reset controller node?
>> >>
>> >> What I could to is to have two instances. One for AHB and one for APB domain.
>> >> Doing this, I will have one instance per domain, and only consecutive registers.
>> >> Is it fine for you?
>> >
>> > Looking at
>> > http://www.st.com/web/en/resource/technical/document/reference_manual/DM00031020.pdf
>> > Table 34 (RCC register map and reset values), I'd say there is a single
>> > "Reset and Clock Control" device at 0x40023800 - 0x40023884:
>> >
>> >         soc {
>> >                 rcc: rcc@40023800 {
>> >                         #clock-cells = <1>;
>> >                         #reset-cells = <1>;
>> >                         compatible = "st,stm32-rcc";
>> >                         reg = <0x40023800 0x84>;
>> >                 };
>> >
>> >                 ...
>> >
>> > If you really want to describe the reset controller parts (offsets +0x10
>> > to +0x24) in a separate node, I won't argue against it too long,
>> > although this is a somewhat arbitrary decision.
>> >
>> > In any case, the whole register at offset +0x1c is reserved, so there is
>> > no reason to split the reset controller. It is ok to have unused ranges
>> > as is already the case with reserved bits inside the used registers.
>>
>> Ok. I understand your point.
>> But it will be more difficult at usage, because the node referencing
>> the fourth reset bit of apb2 register will have to pass 164 as
>> parameter.
>> It is error prone IMHO.
>>
>> Other solution would be to add some defines for each reset line in the
>> DT-Bindings, as we do today for STi platform.
>> But it is giving an unneeded constraint between DT and reset trees.
>
> That is a bit unfortunate, but providing the named constants in
> include/dt-bindings/reset/ makes for a much better readable device tree,
> so I'd prefer that solution, even if it means having to coordinate pull
> requests.

Ok, I will add constants in include/dt-bindings/reset/

Thanks,
Maxime

>
> regards
> Philipp
>

Re: [PATCH 00/14] Add support to STMicroelectronics STM32 family

[Andreas Färber]

[-- Attachment #1: Type: text/plain, Size: 5960 bytes --]

Hi Maxime,

Am 12.02.2015 um 18:45 schrieb Maxime Coquelin:
> This patchset adds basic support for STMicroelectronics STM32 series MCUs.
> 
> STM32 MCUs are Cortex-M CPU, used in various applications (consumer
> electronics, industrial applications, hobbyists...).
> Datasheets, user and programming manuals are publicly available on
> STMicroelectronics website.
> 
> With this series applied, the STM32F419 Discovery can boot succesfully.
> 
> Once this series accepted, next steps will be to add DMA support, as USART,
> I2C and SPI IPs don't have any FIFO. Then will come the clock driver, as today
> the bootloader has to be patched to enable the needed clocks.

This is somewhat unfortunate, as I have been working on the same thing
and have demonstrated the STM32F429 Discovery Kit at ARM TechSymposium
Europe in December and submitted a talk for LinuxCon Japan.

https://github.com/afaerber/afboot-stm32
https://github.com/afaerber/linux/commits/stm32

On a brief look, it seems you are further along in terms of code quality
and documenting. Do you spot anything that's missing in your series and
could be added from my branch? The clk controller maybe? Also I already
started looking into gpio and usb drivers. Me too, I skipped DMA support
though.

Regards,
Andreas

> 
> Maxime Coquelin (14):
>   scripts: link-vmlinux: Don't pass page offset to kallsyms if XIP
>     Kernel
>   ARM: ARMv7M: Enlarge vector table to 256 entries
>   clocksource: Add ARM System timer driver
>   reset: Add reset_controller_of_init() function
>   ARM: call reset_controller_of_init from default time_init handler
>   drivers: reset: Add STM32 reset driver
>   clockevent: Add STM32 Timer driver
>   pinctrl: Add pinctrl driver for STM32 MCUs
>   serial: stm32-usart: Add STM32 USART Driver
>   ARM: Add STM32 family machine
>   ARM: dts: Add ARM System timer as clockevent in armv7m
>   ARM: dts: Introduce STM32F429 MCU
>   ARM: configs: Add STM32 defconfig
>   MAINTAINERS: Add entry for STM32 MCUs
> 
>  Documentation/arm/stm32/overview.txt               |  32 +
>  Documentation/arm/stm32/stm32f429-overview.txt     |  22 +
>  .../devicetree/bindings/arm/system_timer.txt       |  15 +
>  .../devicetree/bindings/pinctrl/pinctrl-stm32.txt  |  99 +++
>  .../devicetree/bindings/reset/st,stm32-reset.txt   |  19 +
>  .../devicetree/bindings/serial/st,stm32-usart.txt  |  18 +
>  .../devicetree/bindings/timer/st,stm32-timer.txt   |  19 +
>  MAINTAINERS                                        |   7 +
>  arch/arm/Kconfig                                   |  22 +
>  arch/arm/Makefile                                  |   1 +
>  arch/arm/boot/dts/Makefile                         |   1 +
>  arch/arm/boot/dts/armv7-m.dtsi                     |   7 +
>  arch/arm/boot/dts/stm32f429-disco.dts              |  41 ++
>  arch/arm/boot/dts/stm32f429.dtsi                   | 279 ++++++++
>  arch/arm/configs/stm32_defconfig                   |  72 ++
>  arch/arm/kernel/entry-v7m.S                        |   8 +-
>  arch/arm/kernel/time.c                             |   4 +
>  arch/arm/mach-stm32/Makefile                       |   1 +
>  arch/arm/mach-stm32/Makefile.boot                  |   0
>  arch/arm/mach-stm32/board-dt.c                     |  19 +
>  drivers/clocksource/Kconfig                        |  16 +
>  drivers/clocksource/Makefile                       |   2 +
>  drivers/clocksource/arm_system_timer.c             |  74 ++
>  drivers/clocksource/timer-stm32.c                  | 187 +++++
>  drivers/pinctrl/Kconfig                            |   9 +
>  drivers/pinctrl/Makefile                           |   1 +
>  drivers/pinctrl/pinctrl-stm32.c                    | 779 +++++++++++++++++++++
>  drivers/reset/Makefile                             |   1 +
>  drivers/reset/core.c                               |  20 +
>  drivers/reset/reset-stm32.c                        | 124 ++++
>  drivers/tty/serial/Kconfig                         |  17 +
>  drivers/tty/serial/Makefile                        |   1 +
>  drivers/tty/serial/stm32-usart.c                   | 695 ++++++++++++++++++
>  include/asm-generic/vmlinux.lds.h                  |   4 +-
>  include/dt-bindings/pinctrl/pinctrl-stm32.h        |  43 ++
>  include/linux/reset-controller.h                   |   6 +
>  include/uapi/linux/serial_core.h                   |   3 +
>  scripts/link-vmlinux.sh                            |   2 +-
>  38 files changed, 2664 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/arm/stm32/overview.txt
>  create mode 100644 Documentation/arm/stm32/stm32f429-overview.txt
>  create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
>  create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
>  create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-reset.txt
>  create mode 100644 Documentation/devicetree/bindings/serial/st,stm32-usart.txt
>  create mode 100644 Documentation/devicetree/bindings/timer/st,stm32-timer.txt
>  create mode 100644 arch/arm/boot/dts/stm32f429-disco.dts
>  create mode 100644 arch/arm/boot/dts/stm32f429.dtsi
>  create mode 100644 arch/arm/configs/stm32_defconfig
>  create mode 100644 arch/arm/mach-stm32/Makefile
>  create mode 100644 arch/arm/mach-stm32/Makefile.boot
>  create mode 100644 arch/arm/mach-stm32/board-dt.c
>  create mode 100644 drivers/clocksource/arm_system_timer.c
>  create mode 100644 drivers/clocksource/timer-stm32.c
>  create mode 100644 drivers/pinctrl/pinctrl-stm32.c
>  create mode 100644 drivers/reset/reset-stm32.c
>  create mode 100644 drivers/tty/serial/stm32-usart.c
>  create mode 100644 include/dt-bindings/pinctrl/pinctrl-stm32.h
> 


-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu,
Graham Norton; HRB 21284 (AG Nürnberg)


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

Re: [PATCH 05/14] ARM: call reset_controller_of_init from default time_init handler

[Rob Herring]

On Thu, Feb 12, 2015 at 11:45 AM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:
> Some DT ARM platforms need the reset controllers to be initialized before
> the timers.
> This is the case of the stm32 and sunxi platforms.

I would say this is the exception, not the rule and therefore should
be handled in a machine desc function. Or it could be part of your
timer setup. Or is the bootloader's problem (like arch timer setup).

We just want to limit how much this mechanism gets used.

Rob

>
> This patch adds a call to reset_controller_of_init() to the default
> .init_time callback when RESET_CONTROLLER is used by the platform.
>
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> ---
>  arch/arm/kernel/time.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
> index 0cc7e58..4601b1e 100644
> --- a/arch/arm/kernel/time.c
> +++ b/arch/arm/kernel/time.c
> @@ -20,6 +20,7 @@
>  #include <linux/irq.h>
>  #include <linux/kernel.h>
>  #include <linux/profile.h>
> +#include <linux/reset-controller.h>
>  #include <linux/sched.h>
>  #include <linux/sched_clock.h>
>  #include <linux/smp.h>
> @@ -117,6 +118,9 @@ void __init time_init(void)
>         if (machine_desc->init_time) {
>                 machine_desc->init_time();
>         } else {
> +#ifdef CONFIG_RESET_CONTROLLER
> +               reset_controller_of_init();
> +#endif
>  #ifdef CONFIG_COMMON_CLK
>                 of_clk_init(NULL);
>  #endif
> --
> 1.9.1
>

Re: [PATCH 03/14] clocksource: Add ARM System timer driver

[Rob Herring]

On Thu, Feb 12, 2015 at 11:45 AM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:
> This patch adds clocksource support for ARMv7-M's System timer,
> also known as SysTick.
>
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> ---
>  .../devicetree/bindings/arm/system_timer.txt       | 15 +++++

Please include v7M in the name. System timer sounds very generic. This
is the only timer architecturally defined IIRC, so perhaps just
"armv7m_systick".

>  drivers/clocksource/Kconfig                        |  7 ++
>  drivers/clocksource/Makefile                       |  1 +
>  drivers/clocksource/arm_system_timer.c             | 74 ++++++++++++++++++++++

Same here.


>  4 files changed, 97 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
>  create mode 100644 drivers/clocksource/arm_system_timer.c
>
> diff --git a/Documentation/devicetree/bindings/arm/system_timer.txt b/Documentation/devicetree/bindings/arm/system_timer.txt
> new file mode 100644
> index 0000000..35268b7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/system_timer.txt
> @@ -0,0 +1,15 @@
> +* ARM System Timer
> +
> +ARMv7-M includes a system timer, known as SysTick. Current driver only
> +implements the clocksource feature.
> +
> +Required properties:
> +- compatible : Should be "arm,armv7m-systick"
> +- reg       : The address range of the timer
> +- clocks     : The input clock of the timer

You may want to consider supporting "clock-frequency" here too. In
more simple chips you may just have fixed clocks and may want to run a
kernel with COMMON_CLK disabled for size savings.

> +
> +systick: system-timer {

This should be "systick: timer@e000e010".

Same for your dts file.

> +       compatible = "arm,armv7m-systick";
> +       reg = <0xe000e010 0x10>;
> +       clocks = <&clk_systick>;
> +};
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index fc01ec2..f9fe4ac 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -124,6 +124,13 @@ config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
>         help
>          Use ARM global timer clock source as sched_clock
>
> +config ARM_SYSTEM_TIMER
> +       bool
> +       select CLKSRC_OF if OF
> +       select CLKSRC_MMIO
> +       help
> +         This options enables support for the ARM system timer unit
> +
>  config ATMEL_PIT
>         select CLKSRC_OF if OF
>         def_bool SOC_AT91SAM9 || SOC_SAMA5
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index 94d90b2..194400b 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -42,6 +42,7 @@ obj-$(CONFIG_MTK_TIMER)               += mtk_timer.o
>
>  obj-$(CONFIG_ARM_ARCH_TIMER)           += arm_arch_timer.o
>  obj-$(CONFIG_ARM_GLOBAL_TIMER)         += arm_global_timer.o
> +obj-$(CONFIG_ARM_SYSTEM_TIMER)         += arm_system_timer.o
>  obj-$(CONFIG_CLKSRC_METAG_GENERIC)     += metag_generic.o
>  obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)  += dummy_timer.o
>  obj-$(CONFIG_ARCH_KEYSTONE)            += timer-keystone.o
> diff --git a/drivers/clocksource/arm_system_timer.c b/drivers/clocksource/arm_system_timer.c
> new file mode 100644
> index 0000000..69e6ef9
> --- /dev/null
> +++ b/drivers/clocksource/arm_system_timer.c
> @@ -0,0 +1,74 @@
> +/*
> + * Copyright (C) Maxime Coquelin 2015
> + * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
> + * License terms:  GNU General Public License (GPL), version 2
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/clocksource.h>
> +#include <linux/clockchips.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/clk.h>
> +#include <linux/bitops.h>
> +
> +#define SYST_CSR       0x00
> +#define SYST_RVR       0x04
> +#define SYST_CVR       0x08
> +#define SYST_CALIB     0x0c
> +
> +#define SYST_CSR_ENABLE BIT(0)
> +
> +#define SYSTICK_LOAD_RELOAD_MASK 0x00FFFFFF
> +
> +static void __init system_timer_of_register(struct device_node *np)
> +{
> +       struct clk *clk;
> +       void __iomem *base;
> +       unsigned long rate;
> +       int ret;
> +
> +       base = of_iomap(np, 0);
> +       if (!base) {
> +               pr_warn("system-timer: invalid base address\n");
> +               return;
> +       }
> +
> +       clk = of_clk_get(np, 0);
> +       if (IS_ERR(clk)) {
> +               pr_warn("system-timer: clk not found\n");
> +               ret = PTR_ERR(clk);
> +               goto out_unmap;
> +       }
> +
> +       ret = clk_prepare_enable(clk);
> +       if (ret)
> +               goto out_clk_put;
> +
> +       rate = clk_get_rate(clk);
> +
> +       writel_relaxed(SYSTICK_LOAD_RELOAD_MASK, base + SYST_RVR);
> +       writel_relaxed(SYST_CSR_ENABLE, base + SYST_CSR);
> +
> +       ret = clocksource_mmio_init(base + SYST_CVR, "arm_system_timer", rate,
> +                       200, 24, clocksource_mmio_readl_down);
> +       if (ret) {
> +               pr_err("failed to init clocksource (%d)\n", ret);
> +               goto out_clk_disable;
> +       }
> +
> +       pr_info("ARM System timer initialized as clocksource\n");
> +
> +       return;
> +
> +out_clk_disable:
> +       clk_disable_unprepare(clk);
> +out_clk_put:
> +       clk_put(clk);
> +out_unmap:
> +       iounmap(base);
> +       WARN(ret, "ARM System timer register failed (%d)\n", ret);
> +}
> +
> +CLOCKSOURCE_OF_DECLARE(arm_systick, "arm,armv7m-systick",
> +                       system_timer_of_register);
> --
> 1.9.1
>

Re: [PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Rob Herring]

On Fri, Feb 13, 2015 at 2:42 AM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:
> Hi Geert,
>
> 2015-02-12 21:34 GMT+01:00 Geert Uytterhoeven <geert@linux-m68k.org>:
>> On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
>> <mcoquelin.stm32@gmail.com> wrote:
>>> From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
>>> interrupts. So the number of entries in vectors table is 256.
>>>
>>> This patch adds the missing entries, and change the alignement, so that
>>> vector_table remains naturally aligned.
>>
>> Shouldn't this depend on ARCH_STM32, or some other M4 or M7 specific
>> Kconfig option, to avoid wasting the space on other CPUs?
>
> Actually, the STM32F429 has 90 interrupts, so it would need 106
> entries in the vector table.
> The maximum of supported interrupts is not only for Cortex-M4 and M7,
> this is also true for Cortex-M3.
>
> I see two possibilities:
>  1 - We declare the vector table for the maximum supported number of
> IRQs, as this patch does.
>         - Pro: it will be functionnal with all Cortex-M MCUs
>         - Con: Waste of less than 1KB for memory

The waste depends on the alignment size as well and could be up to
almost 2KB worst case. It varies depending on the padding. We should
try to place it so it always aligned and the wasted space is
minimized.

Rob

>  2 - We introduce a config flag that provides the number of interrupts
>         - Pro: No more memory waste
>         - Con: Need to declare a per MCU model config flag.
>
> Then, regarding the natural alignment, is there a way to ensure it
> depending on the value of a config flag?
> Or we should keep it at the maximum value possible?
>
> Any feedback will be appreciated, especially from Uwe who maintains
> the efm32 machine.
>
> Kind regards,
> Maxime

Re: [PATCH 05/14] ARM: call reset_controller_of_init from default time_init handler

[Russell King - ARM Linux]

On Sun, Feb 15, 2015 at 04:17:31PM -0600, Rob Herring wrote:
> On Thu, Feb 12, 2015 at 11:45 AM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
> > Some DT ARM platforms need the reset controllers to be initialized before
> > the timers.
> > This is the case of the stm32 and sunxi platforms.
> 
> I would say this is the exception, not the rule and therefore should
> be handled in a machine desc function. Or it could be part of your
> timer setup. Or is the bootloader's problem (like arch timer setup).
> 
> We just want to limit how much this mechanism gets used.

Can you clarify please - what is "this mechanism"?  Placing explicit
calls at this location, or the whole OF_DECLARE_* stuff?

Sebastian suggested using the OF_DECLARE_* stuff for the Dove PMU -
so maybe you have a comment on that too?

Thanks.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.

Re: [PATCH 03/14] clocksource: Add ARM System timer driver

[Andreas Färber]

Am 12.02.2015 um 18:45 schrieb Maxime Coquelin:
> This patch adds clocksource support for ARMv7-M's System timer,
> also known as SysTick.
> 
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> ---
>  .../devicetree/bindings/arm/system_timer.txt       | 15 +++++
>  drivers/clocksource/Kconfig                        |  7 ++
>  drivers/clocksource/Makefile                       |  1 +
>  drivers/clocksource/arm_system_timer.c             | 74 ++++++++++++++++++++++
>  4 files changed, 97 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
>  create mode 100644 drivers/clocksource/arm_system_timer.c
> 
> diff --git a/Documentation/devicetree/bindings/arm/system_timer.txt b/Documentation/devicetree/bindings/arm/system_timer.txt
> new file mode 100644
> index 0000000..35268b7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/system_timer.txt
> @@ -0,0 +1,15 @@
> +* ARM System Timer
> +
> +ARMv7-M includes a system timer, known as SysTick. Current driver only
> +implements the clocksource feature.
> +
> +Required properties:
> +- compatible : Should be "arm,armv7m-systick"
> +- reg	     : The address range of the timer
> +- clocks     : The input clock of the timer
> +
> +systick: system-timer {
> +	compatible = "arm,armv7m-systick";
> +	reg = <0xe000e010 0x10>;
> +	clocks = <&clk_systick>;
> +};

Binding documentation is supposed to go into its own patch:
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/submitting-patches.txt

> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index fc01ec2..f9fe4ac 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -124,6 +124,13 @@ config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
>  	help
>  	 Use ARM global timer clock source as sched_clock
>  
> +config ARM_SYSTEM_TIMER
> +	bool
> +	select CLKSRC_OF if OF
> +	select CLKSRC_MMIO
> +	help
> +	  This options enables support for the ARM system timer unit
> +
>  config ATMEL_PIT
>  	select CLKSRC_OF if OF
>  	def_bool SOC_AT91SAM9 || SOC_SAMA5
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index 94d90b2..194400b 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -42,6 +42,7 @@ obj-$(CONFIG_MTK_TIMER)		+= mtk_timer.o
>  
>  obj-$(CONFIG_ARM_ARCH_TIMER)		+= arm_arch_timer.o
>  obj-$(CONFIG_ARM_GLOBAL_TIMER)		+= arm_global_timer.o
> +obj-$(CONFIG_ARM_SYSTEM_TIMER)		+= arm_system_timer.o
>  obj-$(CONFIG_CLKSRC_METAG_GENERIC)	+= metag_generic.o
>  obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)	+= dummy_timer.o
>  obj-$(CONFIG_ARCH_KEYSTONE)		+= timer-keystone.o
> diff --git a/drivers/clocksource/arm_system_timer.c b/drivers/clocksource/arm_system_timer.c
> new file mode 100644
> index 0000000..69e6ef9
> --- /dev/null
> +++ b/drivers/clocksource/arm_system_timer.c
> @@ -0,0 +1,74 @@
> +/*
> + * Copyright (C) Maxime Coquelin 2015
> + * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
> + * License terms:  GNU General Public License (GPL), version 2
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/clocksource.h>
> +#include <linux/clockchips.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/clk.h>
> +#include <linux/bitops.h>
> +
> +#define SYST_CSR	0x00
> +#define SYST_RVR	0x04
> +#define SYST_CVR	0x08
> +#define SYST_CALIB	0x0c
> +
> +#define SYST_CSR_ENABLE BIT(0)
> +
> +#define SYSTICK_LOAD_RELOAD_MASK 0x00FFFFFF
> +
> +static void __init system_timer_of_register(struct device_node *np)
> +{
> +	struct clk *clk;
> +	void __iomem *base;
> +	unsigned long rate;
> +	int ret;
> +
> +	base = of_iomap(np, 0);
> +	if (!base) {
> +		pr_warn("system-timer: invalid base address\n");
> +		return;
> +	}
> +
> +	clk = of_clk_get(np, 0);
> +	if (IS_ERR(clk)) {
> +		pr_warn("system-timer: clk not found\n");
> +		ret = PTR_ERR(clk);
> +		goto out_unmap;
> +	}
> +
> +	ret = clk_prepare_enable(clk);
> +	if (ret)
> +		goto out_clk_put;
> +
> +	rate = clk_get_rate(clk);
> +
> +	writel_relaxed(SYSTICK_LOAD_RELOAD_MASK, base + SYST_RVR);
> +	writel_relaxed(SYST_CSR_ENABLE, base + SYST_CSR);
> +
> +	ret = clocksource_mmio_init(base + SYST_CVR, "arm_system_timer", rate,
> +			200, 24, clocksource_mmio_readl_down);
> +	if (ret) {
> +		pr_err("failed to init clocksource (%d)\n", ret);
> +		goto out_clk_disable;
> +	}
> +
> +	pr_info("ARM System timer initialized as clocksource\n");
> +
> +	return;
> +
> +out_clk_disable:
> +	clk_disable_unprepare(clk);
> +out_clk_put:
> +	clk_put(clk);
> +out_unmap:
> +	iounmap(base);
> +	WARN(ret, "ARM System timer register failed (%d)\n", ret);
> +}
> +
> +CLOCKSOURCE_OF_DECLARE(arm_systick, "arm,armv7m-systick",
> +			system_timer_of_register);

I've used a SysTick based implementation on my stm32 branch myself, but
looking at efm32 I got the impression that it would be better to use one
of the 32-bit TIM2/TIM5 as clocksource and the other as clockevents?

Still this implementation will be handy to have, also for other targets.

Regards,
Andreas

-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu,
Graham Norton; HRB 21284 (AG Nürnberg)

Re: [PATCH 06/14] drivers: reset: Add STM32 reset driver

[Andreas Färber]

Am 12.02.2015 um 18:45 schrieb Maxime Coquelin:
> The STM32 MCUs family IP can be reset by accessing some shared registers.
> 
> The specificity is that some reset lines are used by the timers.
> At timer initialization time, the timer has to be reset, that's why
> we cannot use a regular driver.
> 
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> ---
>  .../devicetree/bindings/reset/st,stm32-reset.txt   |  19 ++++
>  drivers/reset/Makefile                             |   1 +
>  drivers/reset/reset-stm32.c                        | 124 +++++++++++++++++++++
>  3 files changed, 144 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-reset.txt
>  create mode 100644 drivers/reset/reset-stm32.c
> 
> diff --git a/Documentation/devicetree/bindings/reset/st,stm32-reset.txt b/Documentation/devicetree/bindings/reset/st,stm32-reset.txt
> new file mode 100644
> index 0000000..add1298
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reset/st,stm32-reset.txt
> @@ -0,0 +1,19 @@
> +STMicroelectronics STM32 Peripheral Reset Controller
> +====================================================
> +
> +Please also refer to reset.txt in this directory for common reset
> +controller binding usage.
> +
> +Required properties:
> +- compatible: Should be "st,stm32-reset"
> +- reg: should be register base and length as documented in the
> +  datasheet
> +- #reset-cells: 1, see below
> +
> +example:
> +
> +reset_ahb1: reset@40023810 {
> +	#reset-cells = <1>;
> +	compatible = "st,stm32-reset";
> +	reg = <0x40023810 0x4>;
> +};
[snip]

RM0090 has two different chapters on the RCC IP:
* Reset and clock control for STM32F42xxx and STM32F43xxx (RCC)
* Reset and clock control for STM32F405xx/07xx and STM32F415xx/17xx(RCC)

I therefore feel it is wrong to use "stm32-" here; instead I used
"st,stm32f429-rcc" (also relates to 12/14 discussion). This may apply to
other identifiers, too.

Regards,
Andreas

-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu,
Graham Norton; HRB 21284 (AG Nürnberg)

Re: [PATCH 00/14] Add support to STMicroelectronics STM32 family

[Maxime Coquelin]

Hi Andreas,

2015-02-15 16:14 GMT+01:00 Andreas Färber <afaerber@suse.de>:
> Hi Maxime,
>
> Am 12.02.2015 um 18:45 schrieb Maxime Coquelin:
>> This patchset adds basic support for STMicroelectronics STM32 series MCUs.
>>
>> STM32 MCUs are Cortex-M CPU, used in various applications (consumer
>> electronics, industrial applications, hobbyists...).
>> Datasheets, user and programming manuals are publicly available on
>> STMicroelectronics website.
>>
>> With this series applied, the STM32F419 Discovery can boot succesfully.
>>
>> Once this series accepted, next steps will be to add DMA support, as USART,
>> I2C and SPI IPs don't have any FIFO. Then will come the clock driver, as today
>> the bootloader has to be patched to enable the needed clocks.
>
> This is somewhat unfortunate, as I have been working on the same thing
> and have demonstrated the STM32F429 Discovery Kit at ARM TechSymposium
> Europe in December and submitted a talk for LinuxCon Japan.
>
> https://github.com/afaerber/afboot-stm32
> https://github.com/afaerber/linux/commits/stm32

Hmm, I wasn't aware you were also working on it.
The good news is that we are not alone on this task :).
I do it on my spare time, so any contribution is more than welcome.

>
> On a brief look, it seems you are further along in terms of code quality
> and documenting. Do you spot anything that's missing in your series and
> could be added from my branch? The clk controller maybe? Also I already
> started looking into gpio and usb drivers. Me too, I skipped DMA support
> though.

The GPIO support is already part of the pinctrl patch.
The missing thing is the GPIO interrupt feature, but I am working on it.

Maybe you could focus on the clock support, as I see its support is
well advanced in you tree?
I see one bug in it, the timer clocks should be 90MHz, but your patch
indicates 45MHz.

I see you have started the LCD controller driver, maybe that is
another task you could handle?

Regarding USB, have you made it to work?

Kind regards,
Maxime

>
> Regards,
> Andreas
>
>>
>> Maxime Coquelin (14):
>>   scripts: link-vmlinux: Don't pass page offset to kallsyms if XIP
>>     Kernel
>>   ARM: ARMv7M: Enlarge vector table to 256 entries
>>   clocksource: Add ARM System timer driver
>>   reset: Add reset_controller_of_init() function
>>   ARM: call reset_controller_of_init from default time_init handler
>>   drivers: reset: Add STM32 reset driver
>>   clockevent: Add STM32 Timer driver
>>   pinctrl: Add pinctrl driver for STM32 MCUs
>>   serial: stm32-usart: Add STM32 USART Driver
>>   ARM: Add STM32 family machine
>>   ARM: dts: Add ARM System timer as clockevent in armv7m
>>   ARM: dts: Introduce STM32F429 MCU
>>   ARM: configs: Add STM32 defconfig
>>   MAINTAINERS: Add entry for STM32 MCUs
>>
>>  Documentation/arm/stm32/overview.txt               |  32 +
>>  Documentation/arm/stm32/stm32f429-overview.txt     |  22 +
>>  .../devicetree/bindings/arm/system_timer.txt       |  15 +
>>  .../devicetree/bindings/pinctrl/pinctrl-stm32.txt  |  99 +++
>>  .../devicetree/bindings/reset/st,stm32-reset.txt   |  19 +
>>  .../devicetree/bindings/serial/st,stm32-usart.txt  |  18 +
>>  .../devicetree/bindings/timer/st,stm32-timer.txt   |  19 +
>>  MAINTAINERS                                        |   7 +
>>  arch/arm/Kconfig                                   |  22 +
>>  arch/arm/Makefile                                  |   1 +
>>  arch/arm/boot/dts/Makefile                         |   1 +
>>  arch/arm/boot/dts/armv7-m.dtsi                     |   7 +
>>  arch/arm/boot/dts/stm32f429-disco.dts              |  41 ++
>>  arch/arm/boot/dts/stm32f429.dtsi                   | 279 ++++++++
>>  arch/arm/configs/stm32_defconfig                   |  72 ++
>>  arch/arm/kernel/entry-v7m.S                        |   8 +-
>>  arch/arm/kernel/time.c                             |   4 +
>>  arch/arm/mach-stm32/Makefile                       |   1 +
>>  arch/arm/mach-stm32/Makefile.boot                  |   0
>>  arch/arm/mach-stm32/board-dt.c                     |  19 +
>>  drivers/clocksource/Kconfig                        |  16 +
>>  drivers/clocksource/Makefile                       |   2 +
>>  drivers/clocksource/arm_system_timer.c             |  74 ++
>>  drivers/clocksource/timer-stm32.c                  | 187 +++++
>>  drivers/pinctrl/Kconfig                            |   9 +
>>  drivers/pinctrl/Makefile                           |   1 +
>>  drivers/pinctrl/pinctrl-stm32.c                    | 779 +++++++++++++++++++++
>>  drivers/reset/Makefile                             |   1 +
>>  drivers/reset/core.c                               |  20 +
>>  drivers/reset/reset-stm32.c                        | 124 ++++
>>  drivers/tty/serial/Kconfig                         |  17 +
>>  drivers/tty/serial/Makefile                        |   1 +
>>  drivers/tty/serial/stm32-usart.c                   | 695 ++++++++++++++++++
>>  include/asm-generic/vmlinux.lds.h                  |   4 +-
>>  include/dt-bindings/pinctrl/pinctrl-stm32.h        |  43 ++
>>  include/linux/reset-controller.h                   |   6 +
>>  include/uapi/linux/serial_core.h                   |   3 +
>>  scripts/link-vmlinux.sh                            |   2 +-
>>  38 files changed, 2664 insertions(+), 6 deletions(-)
>>  create mode 100644 Documentation/arm/stm32/overview.txt
>>  create mode 100644 Documentation/arm/stm32/stm32f429-overview.txt
>>  create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
>>  create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
>>  create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-reset.txt
>>  create mode 100644 Documentation/devicetree/bindings/serial/st,stm32-usart.txt
>>  create mode 100644 Documentation/devicetree/bindings/timer/st,stm32-timer.txt
>>  create mode 100644 arch/arm/boot/dts/stm32f429-disco.dts
>>  create mode 100644 arch/arm/boot/dts/stm32f429.dtsi
>>  create mode 100644 arch/arm/configs/stm32_defconfig
>>  create mode 100644 arch/arm/mach-stm32/Makefile
>>  create mode 100644 arch/arm/mach-stm32/Makefile.boot
>>  create mode 100644 arch/arm/mach-stm32/board-dt.c
>>  create mode 100644 drivers/clocksource/arm_system_timer.c
>>  create mode 100644 drivers/clocksource/timer-stm32.c
>>  create mode 100644 drivers/pinctrl/pinctrl-stm32.c
>>  create mode 100644 drivers/reset/reset-stm32.c
>>  create mode 100644 drivers/tty/serial/stm32-usart.c
>>  create mode 100644 include/dt-bindings/pinctrl/pinctrl-stm32.h
>>
>
>
> --
> SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu,
> Graham Norton; HRB 21284 (AG Nürnberg)
>

Re: [PATCH 05/14] ARM: call reset_controller_of_init from default time_init handler

[Maxime Coquelin]

2015-02-15 23:17 GMT+01:00 Rob Herring <robherring2@gmail.com>:
> On Thu, Feb 12, 2015 at 11:45 AM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
>> Some DT ARM platforms need the reset controllers to be initialized before
>> the timers.
>> This is the case of the stm32 and sunxi platforms.
>
> I would say this is the exception, not the rule and therefore should
> be handled in a machine desc function. Or it could be part of your
> timer setup. Or is the bootloader's problem (like arch timer setup).

The only valid way in my opinion would be to implement the init_time
callback (as your first proposal),
duplicating what performs the time_init() function.

Then, if other machines than sunxi and stm32 have some day the same need,
we could consider moving the call to reset_controller_of_init()
function to time_init().

>
> We just want to limit how much this mechanism gets used.

Could you elaborate the reason why we want to limit this mechanism please?
I am not sure to understand.

Thanks,
Maxime

>
> Rob
>
>>
>> This patch adds a call to reset_controller_of_init() to the default
>> .init_time callback when RESET_CONTROLLER is used by the platform.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>> ---
>>  arch/arm/kernel/time.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
>> index 0cc7e58..4601b1e 100644
>> --- a/arch/arm/kernel/time.c
>> +++ b/arch/arm/kernel/time.c
>> @@ -20,6 +20,7 @@
>>  #include <linux/irq.h>
>>  #include <linux/kernel.h>
>>  #include <linux/profile.h>
>> +#include <linux/reset-controller.h>
>>  #include <linux/sched.h>
>>  #include <linux/sched_clock.h>
>>  #include <linux/smp.h>
>> @@ -117,6 +118,9 @@ void __init time_init(void)
>>         if (machine_desc->init_time) {
>>                 machine_desc->init_time();
>>         } else {
>> +#ifdef CONFIG_RESET_CONTROLLER
>> +               reset_controller_of_init();
>> +#endif
>>  #ifdef CONFIG_COMMON_CLK
>>                 of_clk_init(NULL);
>>  #endif
>> --
>> 1.9.1
>>

Re: [PATCH 03/14] clocksource: Add ARM System timer driver

[Maxime Coquelin]

2015-02-15 23:31 GMT+01:00 Rob Herring <robherring2@gmail.com>:
> On Thu, Feb 12, 2015 at 11:45 AM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
>> This patch adds clocksource support for ARMv7-M's System timer,
>> also known as SysTick.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>> ---
>>  .../devicetree/bindings/arm/system_timer.txt       | 15 +++++
>
> Please include v7M in the name. System timer sounds very generic. This
> is the only timer architecturally defined IIRC, so perhaps just
> "armv7m_systick".

Ok, let's go for "armv7m_systick".

>
>>  drivers/clocksource/Kconfig                        |  7 ++
>>  drivers/clocksource/Makefile                       |  1 +
>>  drivers/clocksource/arm_system_timer.c             | 74 ++++++++++++++++++++++
>
> Same here.

Agree, will be in the v2.

>
>
>>  4 files changed, 97 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
>>  create mode 100644 drivers/clocksource/arm_system_timer.c
>>
>> diff --git a/Documentation/devicetree/bindings/arm/system_timer.txt b/Documentation/devicetree/bindings/arm/system_timer.txt
>> new file mode 100644
>> index 0000000..35268b7
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/system_timer.txt
>> @@ -0,0 +1,15 @@
>> +* ARM System Timer
>> +
>> +ARMv7-M includes a system timer, known as SysTick. Current driver only
>> +implements the clocksource feature.
>> +
>> +Required properties:
>> +- compatible : Should be "arm,armv7m-systick"
>> +- reg       : The address range of the timer
>> +- clocks     : The input clock of the timer
>
> You may want to consider supporting "clock-frequency" here too. In
> more simple chips you may just have fixed clocks and may want to run a
> kernel with COMMON_CLK disabled for size savings.

Ok, I will add this option in the v2.

>
>> +
>> +systick: system-timer {
>
> This should be "systick: timer@e000e010".
>
> Same for your dts file.

Right, it will be fixed in the v2.

Thanks for the review,
Maxime

Re: [PATCH 03/14] clocksource: Add ARM System timer driver

[Maxime Coquelin]

2015-02-16 0:43 GMT+01:00 Andreas Färber <afaerber@suse.de>:
> Am 12.02.2015 um 18:45 schrieb Maxime Coquelin:
>> This patch adds clocksource support for ARMv7-M's System timer,
>> also known as SysTick.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>> ---
>>  .../devicetree/bindings/arm/system_timer.txt       | 15 +++++
>>  drivers/clocksource/Kconfig                        |  7 ++
>>  drivers/clocksource/Makefile                       |  1 +
>>  drivers/clocksource/arm_system_timer.c             | 74 ++++++++++++++++++++++
>>  4 files changed, 97 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
>>  create mode 100644 drivers/clocksource/arm_system_timer.c
>>
>> diff --git a/Documentation/devicetree/bindings/arm/system_timer.txt b/Documentation/devicetree/bindings/arm/system_timer.txt
>> new file mode 100644
>> index 0000000..35268b7
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/system_timer.txt
>> @@ -0,0 +1,15 @@
>> +* ARM System Timer
>> +
>> +ARMv7-M includes a system timer, known as SysTick. Current driver only
>> +implements the clocksource feature.
>> +
>> +Required properties:
>> +- compatible : Should be "arm,armv7m-systick"
>> +- reg             : The address range of the timer
>> +- clocks     : The input clock of the timer
>> +
>> +systick: system-timer {
>> +     compatible = "arm,armv7m-systick";
>> +     reg = <0xe000e010 0x10>;
>> +     clocks = <&clk_systick>;
>> +};
>
> Binding documentation is supposed to go into its own patch:
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/submitting-patches.txt
Ok, will change this in the v2.

>
...
>
> I've used a SysTick based implementation on my stm32 branch myself, but
> looking at efm32 I got the impression that it would be better to use one
> of the 32-bit TIM2/TIM5 as clocksource and the other as clockevents?
>
> Still this implementation will be handy to have, also for other targets.

My view is that we should use as much generic parts of the Cortex-M as possible.
Moreover, doing, that, we can keep one more IP instance under reset
with associated clock gated,
and so maybe reduce the power consumption a little (I haven't done any
measurements)

Do you see a case where it could be better to use the STM32 timers?


Thanks,
Maxime
>
> Regards,
> Andreas
>
> --
> SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu,
> Graham Norton; HRB 21284 (AG Nürnberg)

Re: [PATCH 06/14] drivers: reset: Add STM32 reset driver

[Maxime Coquelin]

2015-02-16 0:59 GMT+01:00 Andreas Färber <afaerber@suse.de>:
> Am 12.02.2015 um 18:45 schrieb Maxime Coquelin:
>> The STM32 MCUs family IP can be reset by accessing some shared registers.
>>
>> The specificity is that some reset lines are used by the timers.
>> At timer initialization time, the timer has to be reset, that's why
>> we cannot use a regular driver.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>> ---
>>  .../devicetree/bindings/reset/st,stm32-reset.txt   |  19 ++++
>>  drivers/reset/Makefile                             |   1 +
>>  drivers/reset/reset-stm32.c                        | 124 +++++++++++++++++++++
>>  3 files changed, 144 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-reset.txt
>>  create mode 100644 drivers/reset/reset-stm32.c
>>
>> diff --git a/Documentation/devicetree/bindings/reset/st,stm32-reset.txt b/Documentation/devicetree/bindings/reset/st,stm32-reset.txt
>> new file mode 100644
>> index 0000000..add1298
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/reset/st,stm32-reset.txt
>> @@ -0,0 +1,19 @@
>> +STMicroelectronics STM32 Peripheral Reset Controller
>> +====================================================
>> +
>> +Please also refer to reset.txt in this directory for common reset
>> +controller binding usage.
>> +
>> +Required properties:
>> +- compatible: Should be "st,stm32-reset"
>> +- reg: should be register base and length as documented in the
>> +  datasheet
>> +- #reset-cells: 1, see below
>> +
>> +example:
>> +
>> +reset_ahb1: reset@40023810 {
>> +     #reset-cells = <1>;
>> +     compatible = "st,stm32-reset";
>> +     reg = <0x40023810 0x4>;
>> +};
> [snip]
>
> RM0090 has two different chapters on the RCC IP:
> * Reset and clock control for STM32F42xxx and STM32F43xxx (RCC)
> * Reset and clock control for STM32F405xx/07xx and STM32F415xx/17xx(RCC)
>
> I therefore feel it is wrong to use "stm32-" here; instead I used
> "st,stm32f429-rcc" (also relates to 12/14 discussion). This may apply to
> other identifiers, too.

In this first version, the reset driver was really generic, and was
compatible with the STM32 family.
The only difference would have been in the device trees.

Now, from the discussion with Philipp, I will reconsider the
implementation to add some named constants,
so maybe I will reconsider the compatible, it will depend on how I
will implement it.

Thanks,
Maxime

>
> Regards,
> Andreas
>
> --
> SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu,
> Graham Norton; HRB 21284 (AG Nürnberg)

Re: [PATCH 05/14] ARM: call reset_controller_of_init from default time_init handler

[Rob Herring]

On Sun, Feb 15, 2015 at 5:12 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Sun, Feb 15, 2015 at 04:17:31PM -0600, Rob Herring wrote:
>> On Thu, Feb 12, 2015 at 11:45 AM, Maxime Coquelin
>> <mcoquelin.stm32@gmail.com> wrote:
>> > Some DT ARM platforms need the reset controllers to be initialized before
>> > the timers.
>> > This is the case of the stm32 and sunxi platforms.
>>
>> I would say this is the exception, not the rule and therefore should
>> be handled in a machine desc function. Or it could be part of your
>> timer setup. Or is the bootloader's problem (like arch timer setup).
>>
>> We just want to limit how much this mechanism gets used.
>
> Can you clarify please - what is "this mechanism"?  Placing explicit
> calls at this location, or the whole OF_DECLARE_* stuff?

Well, it is both really, but I guess OF_DECLARE_ linker sections are
just an implementation detail of scattering various explicit init
calls. My concern is we'll end up with another initcall like mechanism
and the ordering problems associated with them. For example, what if
another platform needs clocks initialized before the reset controller?
I could see wanting to add gpio, pinctrl, syscon, etc. Another example
is the Beagleboard Cape folks want to read an I2C EEPROM early to
apply overlays before drivers probe. Where do we draw the line?

> Sebastian suggested using the OF_DECLARE_* stuff for the Dove PMU -
> so maybe you have a comment on that too?

I have the same position that it is the exception, not the rule, so
use the machine descriptor. I'm willing to be convinced otherwise, but
I think these cases need to be questioned.

Rob

Re: [PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Maxime Coquelin]

Hi Rob,

2015-02-15 23:42 GMT+01:00 Rob Herring <robherring2@gmail.com>:
> On Fri, Feb 13, 2015 at 2:42 AM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
>> Hi Geert,
>>
>> 2015-02-12 21:34 GMT+01:00 Geert Uytterhoeven <geert@linux-m68k.org>:
>>> On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
>>> <mcoquelin.stm32@gmail.com> wrote:
>>>> From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
>>>> interrupts. So the number of entries in vectors table is 256.
>>>>
>>>> This patch adds the missing entries, and change the alignement, so that
>>>> vector_table remains naturally aligned.
>>>
>>> Shouldn't this depend on ARCH_STM32, or some other M4 or M7 specific
>>> Kconfig option, to avoid wasting the space on other CPUs?
>>
>> Actually, the STM32F429 has 90 interrupts, so it would need 106
>> entries in the vector table.
>> The maximum of supported interrupts is not only for Cortex-M4 and M7,
>> this is also true for Cortex-M3.
>>
>> I see two possibilities:
>>  1 - We declare the vector table for the maximum supported number of
>> IRQs, as this patch does.
>>         - Pro: it will be functionnal with all Cortex-M MCUs
>>         - Con: Waste of less than 1KB for memory
>
> The waste depends on the alignment size as well and could be up to
> almost 2KB worst case. It varies depending on the padding. We should
> try to place it so it always aligned and the wasted space is
> minimized.

Sorry, I just notice I didn't replied to all. That was my question:

Do you mean by forcing its location in the arch/arm/kernel/vmlinux.lds.S file?

Regards,
Maxime

>
> Rob
>
>>  2 - We introduce a config flag that provides the number of interrupts
>>         - Pro: No more memory waste
>>         - Con: Need to declare a per MCU model config flag.
>>
>> Then, regarding the natural alignment, is there a way to ensure it
>> depending on the value of a config flag?
>> Or we should keep it at the maximum value possible?
>>
>> Any feedback will be appreciated, especially from Uwe who maintains
>> the efm32 machine.
>>
>> Kind regards,
>> Maxime

Re: [PATCH 02/14] ARM: ARMv7M: Enlarge vector table to 256 entries

[Rob Herring]

On Thu, Feb 19, 2015 at 10:13 AM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:
> Hi Rob,
>
> 2015-02-15 23:42 GMT+01:00 Rob Herring <robherring2@gmail.com>:
>> On Fri, Feb 13, 2015 at 2:42 AM, Maxime Coquelin
>> <mcoquelin.stm32@gmail.com> wrote:
>>> Hi Geert,
>>>
>>> 2015-02-12 21:34 GMT+01:00 Geert Uytterhoeven <geert@linux-m68k.org>:
>>>> On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
>>>> <mcoquelin.stm32@gmail.com> wrote:
>>>>> From Cortex-M4 and M7 reference manuals, the nvic supports up to 240
>>>>> interrupts. So the number of entries in vectors table is 256.
>>>>>
>>>>> This patch adds the missing entries, and change the alignement, so that
>>>>> vector_table remains naturally aligned.
>>>>
>>>> Shouldn't this depend on ARCH_STM32, or some other M4 or M7 specific
>>>> Kconfig option, to avoid wasting the space on other CPUs?
>>>
>>> Actually, the STM32F429 has 90 interrupts, so it would need 106
>>> entries in the vector table.
>>> The maximum of supported interrupts is not only for Cortex-M4 and M7,
>>> this is also true for Cortex-M3.
>>>
>>> I see two possibilities:
>>>  1 - We declare the vector table for the maximum supported number of
>>> IRQs, as this patch does.
>>>         - Pro: it will be functionnal with all Cortex-M MCUs
>>>         - Con: Waste of less than 1KB for memory
>>
>> The waste depends on the alignment size as well and could be up to
>> almost 2KB worst case. It varies depending on the padding. We should
>> try to place it so it always aligned and the wasted space is
>> minimized.
>
> Sorry, I just notice I didn't replied to all. That was my question:
>
> Do you mean by forcing its location in the arch/arm/kernel/vmlinux.lds.S file?

Yes, that is one way. Or we might be able to just be smarter about how
we arrange the code. The first thing to do is figure out how much
space we waste and what comes before it.

Rob

>
> Regards,
> Maxime
>
>>
>> Rob
>>
>>>  2 - We introduce a config flag that provides the number of interrupts
>>>         - Pro: No more memory waste
>>>         - Con: Need to declare a per MCU model config flag.
>>>
>>> Then, regarding the natural alignment, is there a way to ensure it
>>> depending on the value of a config flag?
>>> Or we should keep it at the maximum value possible?
>>>
>>> Any feedback will be appreciated, especially from Uwe who maintains
>>> the efm32 machine.
>>>
>>> Kind regards,
>>> Maxime

Re: [PATCH 07/14] clockevent: Add STM32 Timer driver

[Linus Walleij]

On Thu, Feb 12, 2015 at 6:45 PM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:

> STM32 MCUs feature 16 and 32 bits general purpose timers with prescalers.
> The drivers detects whether the time is 16 or 32 bits, and applies a
> 1024 prescaler value if it is 16 bits.
>
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>

This is a nice driver.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH 14/14] MAINTAINERS: Add entry for STM32 MCUs

[Linus Walleij]

On Thu, Feb 12, 2015 at 6:46 PM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:

> Add a MAINTAINER entry covering all STM32 machine and drivers files.
>
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>

(...)
> +F:     drivers/clocksource/arm_system_timer.c

Is that all? And that is not even a STM32 specific driver.

Yours,
Linus Walleij

Re: [PATCH 14/14] MAINTAINERS: Add entry for STM32 MCUs

[Maxime Coquelin]

2015-03-06 10:03 GMT+01:00 Linus Walleij <linus.walleij@linaro.org>:
> On Thu, Feb 12, 2015 at 6:46 PM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
>
>> Add a MAINTAINER entry covering all STM32 machine and drivers files.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>
> (...)
>> +F:     drivers/clocksource/arm_system_timer.c
>
> Is that all? And that is not even a STM32 specific driver.

For the ARM System Timer, I'm fine to add a new entry.
Or remove the line, and let the maintain-ship to clocksource maintainers.

All the STM32 files are covered by this line:
+N:     stm32

Thanks,
Maxime
>
> Yours,
> Linus Walleij

Re: [PATCH 14/14] MAINTAINERS: Add entry for STM32 MCUs

[Linus Walleij]

On Fri, Mar 6, 2015 at 10:55 AM, Maxime Coquelin
<mcoquelin.stm32@gmail.com> wrote:
> 2015-03-06 10:03 GMT+01:00 Linus Walleij <linus.walleij@linaro.org>:
>> On Thu, Feb 12, 2015 at 6:46 PM, Maxime Coquelin
>> <mcoquelin.stm32@gmail.com> wrote:
>>
>>> Add a MAINTAINER entry covering all STM32 machine and drivers files.
>>>
>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>>
>> (...)
>>> +F:     drivers/clocksource/arm_system_timer.c
>>
>> Is that all? And that is not even a STM32 specific driver.
>
> For the ARM System Timer, I'm fine to add a new entry.
> Or remove the line, and let the maintain-ship to clocksource maintainers.
>
> All the STM32 files are covered by this line:
> +N:     stm32

Aha you're right, news2me, I'm old and stupid :/

Thanks,
Linus Walleij

Re: [PATCH 14/14] MAINTAINERS: Add entry for STM32 MCUs

[Maxime Coquelin]

2015-03-09 17:47 GMT+01:00 Linus Walleij <linus.walleij@linaro.org>:
> On Fri, Mar 6, 2015 at 10:55 AM, Maxime Coquelin
> <mcoquelin.stm32@gmail.com> wrote:
>> 2015-03-06 10:03 GMT+01:00 Linus Walleij <linus.walleij@linaro.org>:
>>> On Thu, Feb 12, 2015 at 6:46 PM, Maxime Coquelin
>>> <mcoquelin.stm32@gmail.com> wrote:
>>>
>>>> Add a MAINTAINER entry covering all STM32 machine and drivers files.
>>>>
>>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>>>
>>> (...)
>>>> +F:     drivers/clocksource/arm_system_timer.c
>>>
>>> Is that all? And that is not even a STM32 specific driver.
>>
>> For the ARM System Timer, I'm fine to add a new entry.
>> Or remove the line, and let the maintain-ship to clocksource maintainers.
>>
>> All the STM32 files are covered by this line:
>> +N:     stm32
>
> Aha you're right, news2me, I'm old and stupid :/

This is new to me too. :)

Maxime

>
> Thanks,
> Linus Walleij