Devicetree
 help / color / mirror / Atom feed
* Re: [PATCH v2 4/5] fbdev/ssd1307fb: add support to enable VBAT
From: Tomi Valkeinen @ 2017-01-19 13:15 UTC (permalink / raw)
  To: Rob Herring, Jyri Sarha
  Cc: linux-fbdev-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA,
	b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ,
	maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8,
	bcousson-rdvid1DuHRBWk0Htik3J/w
In-Reply-To: <20170118223310.kxbgq47v7cl33ls3@rob-hp-laptop>


[-- Attachment #1.1: Type: text/plain, Size: 1572 bytes --]

On 19/01/17 00:33, Rob Herring wrote:
> On Fri, Jan 13, 2017 at 12:35:48PM +0200, Jyri Sarha wrote:
>> From: Tomi Valkeinen <tomi.valkeinen-l0cyMroinI0@public.gmane.org>
>>
>> SSD1306 needs VBAT when it is wired in charge pump configuration. This
>> patch adds support to the driver to enable VBAT regulator at init time.
>>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen-l0cyMroinI0@public.gmane.org>
>> Reviewed-by: Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>
>> Signed-off-by: Jyri Sarha <jsarha-l0cyMroinI0@public.gmane.org>
>> ---
>>  .../devicetree/bindings/display/ssd1307fb.txt        |  1 +
>>  drivers/video/fbdev/ssd1307fb.c                      | 20 +++++++++++++++++++-
>>  2 files changed, 20 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/display/ssd1307fb.txt b/Documentation/devicetree/bindings/display/ssd1307fb.txt
>> index 6617df6..209d931 100644
>> --- a/Documentation/devicetree/bindings/display/ssd1307fb.txt
>> +++ b/Documentation/devicetree/bindings/display/ssd1307fb.txt
>> @@ -16,6 +16,7 @@ Required properties:
>>  Optional properties:
>>    - reset-gpios: The GPIO used to reset the OLED display, if available. See
>>                   Documentation/devicetree/bindings/gpio/gpio.txt for details.
>> +  - vbat-supply: The supply for VBAT
> 
> According to the datasheet, SSD1307 has 2 supplies: Vdd and Vcc
> 
> I don't see any mention of a charge pump, so that must be an external 
> component.

VBAT is for SSD1306. Perhaps the DT doc should mention it.

 Tomi


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

^ permalink raw reply

* [PATCH v10 0/5] Add support for the STM32F4 I2C
From: M'boumba Cedric Madianga @ 2017-01-19 13:25 UTC (permalink / raw)
  To: wsa, robh+dt, mcoquelin.stm32, alexandre.torgue, linus.walleij,
	patrice.chotard, linux, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, u.kleine-koenig
  Cc: M'boumba Cedric Madianga

This patchset adds support for the I2C controller embedded in STM32F4xx SoC.
It enables I2C transfer in interrupt mode with Standard-mode and Fast-mode bus
speed.

Changes since v9:
- Fix minor typo in some comments
- Add some comments to explain how the driver check TRISE and CCR value have
  no chance of overflow

Changes since v8:
- Rework I2C Clock Control Register computation (Uwe)
- Save register accesses as often as possible (Uwe)
- Don't use mask before saving rx buffer (Uwe)
- Add more comments to explain hardware way of working (Uwe)
- Rename stm32f4_i2c_handle_rx_btf function by stm32f4_i2c_handle_rx_done (Uwe)
- Set/Clear Ack position bit during address match phase

Changes since v7:
- Remove unneeded parenthesis in some macro definitions (Uwe)
- Fix some typo (s/KhzkHZ, s/PEC/POC) (Uwe)
- Fix alignment issues in some structures declaration (Uwe)
- Clarify comments to argue i2c_timing values chosen (Uwe)
- Raise an error if parent clk rate is out of scope during I2C hw config (Uwe)
- Use dev_dbg instead of dev_err message when I2C bus is busy  (Uwe)
- Add more comments about stuff done by stm32f4_i2c_handle_rx_btf() (Uwe)
- Simplify stm32f4_i2c_isr_error() routine implementation by removing possible
  status checking (Uwe)
- Rework stm32f4_i2c_isr_error() routine by removing the loop to check which
  status occured  (Uwe)
- Add open-drain property for SCL pins  (Uwe)
- Rework unneeded mul_ccr field from i2c_timing structure
- Remove min_ccr field from i2c_timing structure as default scl_period is chosen
  to have a correct minimal ccr value
- Execute hw_config once during probe
- Remove soft_reset after an I2C error as all errors are now handled and
  hw_config is done once during probe
- Generate STOP by software when Acknowledge failure occurs
- Set the max speed mode for I2C pins
- Add bias-disable property for I2C pins
- Use intrinsic limitation of APB bus to set I2C max input clk

Changes since v6:
- Add commit message for the patches in defconfig, .dtsi and .dts files (Alex)
- Order I2C instance base address in .dtsi file (Alex)
- Add commit message for the patch in stm32429i-eval.dts  (Alex)
- Add link to the STM32F4 Soc ref manual where I2C device is described (Uwe)
- Use more usal way to define constants with several lines (Uwe)
- Remove rate variable from stm32f4_i2c_timings as it is not used (Uwe)
- Remove irq variable from stm32f4_i2c_dev struct are they are only needed
  during probe (Uwe)
- Add comment from datasheet to explain stm32f4_i2c_timings values (Uwe)
- Rework i2c soft_reset implementation (Uwe)
- Replace "it" by "irq" as it is a more usual abbreviation for interrupt (Uwe)
- Add comment from datasheet to explain periph clk freq calculation (Uwe)
- Use DIV_ROUND_UP instead of plain division when required (Uwe)
- Add comment from datasheet to explain timing rise calculation (Uwe)
- Rework timing rise calculation by using shorter computation (Uwe)
- Remove (u8) cast when reading I2C data register (Uwe)
- Rework isr_event routine to handle several events during one call of the
  routine (Uwe)
- Precise which type of irq is failed when a irq request error occurs (Uwe)
- Use devm_request_irq() instead of devm_request_threaded_irq() to avoid
  spurious evt irq when clearing status registers in threaded context

Changes since v5:
- Change commit header from "ARM: dts:" to "ARM: dts: stm32:" (Alex)
- Change commit header from "ARM: configs:" to "ARM: configs: stm32:" (Alex)
- Fix warnings due to variable set but unused (Wolfram)
- Remove double space in Kconfig (Wolfram)
- Fix warning due to bad type parameter when using clamp() function
  (build-bot)

Changes since v4:
- Use clamp() function to use a value in a given range as it was missed in V4

Changes since v3 after Wolfram's review:
- Add COMPILE_TEST flag in Kconfig
- Use correct driver name in Kconfig i.e i2c-stm32f4 instead of i2c-st
- Use more comprehensible name stm32f4_i2c_msg for client specific data
- Don't store reset control node as just needed in probe
- Use clamp() function to test value between 2 ranges
- Use new "i2c_8bit_addr_from_msg() function to build I2C address
- Don't write error messages for timeout
- Remove error message when i2c_add_adapter() fails as it is already handled by
  the i2c core driver

Changes since v2:
- remove interrupt configuration management from DT
- remove FIFO configuration management from DT except threshold as it is very
  hard to handle it in the driver due to many possible combinations according
  to burst and bus width
- update DMA client message in DT documentation file
- specify the order to be used to set per-channel DMA interrupts in the DT
- remove unused enumerations for channel and request ids
- keep as soon as possible 80 lines char for more readability
- replace unsigned int by u32
- return error if burst is not supported in stm32_dma_get_burst()
- return error if bus_width is not supported in stm32_dma_get_width()
- add FIFO configuration management inside the driver except for threshold
- add interrupt configuration management inside the driver
- rework stm32_dma_chan_irq() to handle error interrupt in one way
- rework stm32_dma_set_xfer_param() to be easier to read
- update stm32_dma_tx_status() to always return status from dma_cookie_status()
- disable clk if we don't manage to stop the DMA channel during channel
  resources allocation
- set driver as built-in as DMA will be required by other built-in driver

Changes since v1:
- use compatible st,stm32f4-i2c instead of st,i2c-stm32f4 (Rob)
- fix typo s/enmpty/empty (Maxime)
- use one function to handle TX fifo empty and byte xfer finished IT (Maxime)
- set duty cycle in timing struct in Fast mode
- Rework clock management (call prepare/unprepare at probe and remove, call
  clk_enable/clk_disable for each I2C transfer)

M'boumba Cedric Madianga (5):
  dt-bindings: Document the STM32 I2C bindings
  i2c: Add STM32F4 I2C driver
  ARM: dts: stm32: Add I2C1 support for STM32F429 SoC
  ARM: dts: stm32: Add I2C1 support for STM32429 eval board
  ARM: configs: stm32: Add I2C support for STM32 defconfig

 .../devicetree/bindings/i2c/i2c-stm32.txt          |  33 +
 arch/arm/boot/dts/stm32429i-eval.dts               |   6 +
 arch/arm/boot/dts/stm32f429.dtsi                   |  23 +
 arch/arm/configs/stm32_defconfig                   |   3 +
 drivers/i2c/busses/Kconfig                         |  10 +
 drivers/i2c/busses/Makefile                        |   1 +
 drivers/i2c/busses/i2c-stm32f4.c                   | 897 +++++++++++++++++++++
 7 files changed, 973 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-stm32.txt
 create mode 100644 drivers/i2c/busses/i2c-stm32f4.c

-- 
1.9.1

^ permalink raw reply

* [PATCH v10 1/5] dt-bindings: Document the STM32 I2C bindings
From: M'boumba Cedric Madianga @ 2017-01-19 13:25 UTC (permalink / raw)
  To: wsa, robh+dt, mcoquelin.stm32, alexandre.torgue, linus.walleij,
	patrice.chotard, linux, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, u.kleine-koenig
  Cc: M'boumba Cedric Madianga
In-Reply-To: <1484832316-5594-1-git-send-email-cedric.madianga@gmail.com>

This patch adds documentation of device tree bindings for the STM32 I2C
controller.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/i2c/i2c-stm32.txt          | 33 ++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-stm32.txt

diff --git a/Documentation/devicetree/bindings/i2c/i2c-stm32.txt b/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
new file mode 100644
index 0000000..78eaf7b
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
@@ -0,0 +1,33 @@
+* I2C controller embedded in STMicroelectronics STM32 I2C platform
+
+Required properties :
+- compatible : Must be "st,stm32f4-i2c"
+- reg : Offset and length of the register set for the device
+- interrupts : Must contain the interrupt id for I2C event and then the
+  interrupt id for I2C error.
+- resets: Must contain the phandle to the reset controller.
+- clocks: Must contain the input clock of the I2C instance.
+- A pinctrl state named "default" must be defined to set pins in mode of
+  operation for I2C transfer
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties :
+- clock-frequency : Desired I2C bus clock frequency in Hz. If not specified,
+  the default 100 kHz frequency will be used. As only Normal and Fast modes
+  are supported, possible values are 100000 and 400000.
+
+Example :
+
+	i2c@40005400 {
+		compatible = "st,stm32f4-i2c";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x40005400 0x400>;
+		interrupts = <31>,
+			     <32>;
+		resets = <&rcc 277>;
+		clocks = <&rcc 0 149>;
+		pinctrl-0 = <&i2c1_sda_pin>, <&i2c1_scl_pin>;
+		pinctrl-names = "default";
+	};
-- 
1.9.1

^ permalink raw reply related

* [PATCH v10 2/5] i2c: Add STM32F4 I2C driver
From: M'boumba Cedric Madianga @ 2017-01-19 13:25 UTC (permalink / raw)
  To: wsa, robh+dt, mcoquelin.stm32, alexandre.torgue, linus.walleij,
	patrice.chotard, linux, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, u.kleine-koenig
  Cc: M'boumba Cedric Madianga
In-Reply-To: <1484832316-5594-1-git-send-email-cedric.madianga@gmail.com>

This patch adds support for the STM32F4 I2C controller.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 drivers/i2c/busses/Kconfig       |  10 +
 drivers/i2c/busses/Makefile      |   1 +
 drivers/i2c/busses/i2c-stm32f4.c | 897 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 908 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-stm32f4.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 0cdc844..2719208 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -886,6 +886,16 @@ config I2C_ST
 	  This driver can also be built as module. If so, the module
 	  will be called i2c-st.
 
+config I2C_STM32F4
+	tristate "STMicroelectronics STM32F4 I2C support"
+	depends on ARCH_STM32 || COMPILE_TEST
+	help
+	  Enable this option to add support for STM32 I2C controller embedded
+	  in STM32F4 SoCs.
+
+	  This driver can also be built as module. If so, the module
+	  will be called i2c-stm32f4.
+
 config I2C_STU300
 	tristate "ST Microelectronics DDC I2C interface"
 	depends on MACH_U300
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 1c1bac8..a2c6ff5 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
 obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
 obj-$(CONFIG_I2C_SIRF)		+= i2c-sirf.o
 obj-$(CONFIG_I2C_ST)		+= i2c-st.o
+obj-$(CONFIG_I2C_STM32F4)	+= i2c-stm32f4.o
 obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_SUN6I_P2WI)	+= i2c-sun6i-p2wi.o
 obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
diff --git a/drivers/i2c/busses/i2c-stm32f4.c b/drivers/i2c/busses/i2c-stm32f4.c
new file mode 100644
index 0000000..f9dd7e8
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stm32f4.c
@@ -0,0 +1,897 @@
+/*
+ * Driver for STMicroelectronics STM32 I2C controller
+ *
+ * This I2C controller is described in the STM32F429/439 Soc reference manual.
+ * Please see below a link to the documentation:
+ * http://www.st.com/resource/en/reference_manual/DM00031020.pdf
+ *
+ * Copyright (C) M'boumba Cedric Madianga 2016
+ * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
+ *
+ * This driver is based on i2c-st.c
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+/* STM32F4 I2C offset registers */
+#define STM32F4_I2C_CR1			0x00
+#define STM32F4_I2C_CR2			0x04
+#define STM32F4_I2C_DR			0x10
+#define STM32F4_I2C_SR1			0x14
+#define STM32F4_I2C_SR2			0x18
+#define STM32F4_I2C_CCR			0x1C
+#define STM32F4_I2C_TRISE		0x20
+#define STM32F4_I2C_FLTR		0x24
+
+/* STM32F4 I2C control 1*/
+#define STM32F4_I2C_CR1_POS		BIT(11)
+#define STM32F4_I2C_CR1_ACK		BIT(10)
+#define STM32F4_I2C_CR1_STOP		BIT(9)
+#define STM32F4_I2C_CR1_START		BIT(8)
+#define STM32F4_I2C_CR1_PE		BIT(0)
+
+/* STM32F4 I2C control 2 */
+#define STM32F4_I2C_CR2_FREQ_MASK	GENMASK(5, 0)
+#define STM32F4_I2C_CR2_FREQ(n)		((n) & STM32F4_I2C_CR2_FREQ_MASK)
+#define STM32F4_I2C_CR2_ITBUFEN		BIT(10)
+#define STM32F4_I2C_CR2_ITEVTEN		BIT(9)
+#define STM32F4_I2C_CR2_ITERREN		BIT(8)
+#define STM32F4_I2C_CR2_IRQ_MASK	(STM32F4_I2C_CR2_ITBUFEN | \
+					 STM32F4_I2C_CR2_ITEVTEN | \
+					 STM32F4_I2C_CR2_ITERREN)
+
+/* STM32F4 I2C Status 1 */
+#define STM32F4_I2C_SR1_AF		BIT(10)
+#define STM32F4_I2C_SR1_ARLO		BIT(9)
+#define STM32F4_I2C_SR1_BERR		BIT(8)
+#define STM32F4_I2C_SR1_TXE		BIT(7)
+#define STM32F4_I2C_SR1_RXNE		BIT(6)
+#define STM32F4_I2C_SR1_BTF		BIT(2)
+#define STM32F4_I2C_SR1_ADDR		BIT(1)
+#define STM32F4_I2C_SR1_SB		BIT(0)
+#define STM32F4_I2C_SR1_ITEVTEN_MASK	(STM32F4_I2C_SR1_BTF | \
+					 STM32F4_I2C_SR1_ADDR | \
+					 STM32F4_I2C_SR1_SB)
+#define STM32F4_I2C_SR1_ITBUFEN_MASK	(STM32F4_I2C_SR1_TXE | \
+					 STM32F4_I2C_SR1_RXNE)
+#define STM32F4_I2C_SR1_ITERREN_MASK	(STM32F4_I2C_SR1_AF | \
+					 STM32F4_I2C_SR1_ARLO | \
+					 STM32F4_I2C_SR1_BERR)
+
+/* STM32F4 I2C Status 2 */
+#define STM32F4_I2C_SR2_BUSY		BIT(1)
+
+/* STM32F4 I2C Control Clock */
+#define STM32F4_I2C_CCR_CCR_MASK	GENMASK(11, 0)
+#define STM32F4_I2C_CCR_CCR(n)		((n) & STM32F4_I2C_CCR_CCR_MASK)
+#define STM32F4_I2C_CCR_FS		BIT(15)
+#define STM32F4_I2C_CCR_DUTY		BIT(14)
+
+/* STM32F4 I2C Trise */
+#define STM32F4_I2C_TRISE_VALUE_MASK	GENMASK(5, 0)
+#define STM32F4_I2C_TRISE_VALUE(n)	((n) & STM32F4_I2C_TRISE_VALUE_MASK)
+
+#define STM32F4_I2C_MIN_STANDARD_FREQ	2U
+#define STM32F4_I2C_MIN_FAST_FREQ	6U
+#define STM32F4_I2C_MAX_FREQ		46U
+#define HZ_TO_MHZ			1000000
+
+enum stm32f4_i2c_speed {
+	STM32F4_I2C_SPEED_STANDARD, /* 100 kHz */
+	STM32F4_I2C_SPEED_FAST, /* 400 kHz */
+	STM32F4_I2C_SPEED_END,
+};
+
+/**
+ * struct stm32f4_i2c_msg - client specific data
+ * @addr: 8-bit slave addr, including r/w bit
+ * @count: number of bytes to be transferred
+ * @buf: data buffer
+ * @result: result of the transfer
+ * @stop: last I2C msg to be sent, i.e. STOP to be generated
+ */
+struct stm32f4_i2c_msg {
+	u8 addr;
+	u32 count;
+	u8 *buf;
+	int result;
+	bool stop;
+};
+
+/**
+ * struct stm32f4_i2c_dev - private data of the controller
+ * @adap: I2C adapter for this controller
+ * @dev: device for this controller
+ * @base: virtual memory area
+ * @complete: completion of I2C message
+ * @clk: hw i2c clock
+ * @speed: I2C clock frequency of the controller. Standard or Fast are supported
+ * @parent_rate: I2C clock parent rate in MHz
+ * @msg: I2C transfer information
+ */
+struct stm32f4_i2c_dev {
+	struct i2c_adapter adap;
+	struct device *dev;
+	void __iomem *base;
+	struct completion complete;
+	struct clk *clk;
+	int speed;
+	int parent_rate;
+	struct stm32f4_i2c_msg msg;
+};
+
+static inline void stm32f4_i2c_set_bits(void __iomem *reg, u32 mask)
+{
+	writel_relaxed(readl_relaxed(reg) | mask, reg);
+}
+
+static inline void stm32f4_i2c_clr_bits(void __iomem *reg, u32 mask)
+{
+	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
+}
+
+static void stm32f4_i2c_disable_irq(struct stm32f4_i2c_dev *i2c_dev)
+{
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_IRQ_MASK);
+}
+
+static int stm32f4_i2c_set_periph_clk_freq(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 freq;
+	u32 cr2 = 0;
+
+	i2c_dev->parent_rate = clk_get_rate(i2c_dev->clk);
+	freq = DIV_ROUND_UP(i2c_dev->parent_rate, HZ_TO_MHZ);
+
+	if (i2c_dev->speed == STM32F4_I2C_SPEED_STANDARD) {
+		/*
+		 * To reach 100 kHz, the parent clk frequency should be between
+		 * a minimum value of 2 MHz and a maximum value of 46 MHz due
+		 * to hardware limitation
+		 */
+		if (freq < STM32F4_I2C_MIN_STANDARD_FREQ ||
+		    freq > STM32F4_I2C_MAX_FREQ) {
+			dev_err(i2c_dev->dev,
+				"bad parent clk freq for standard mode\n");
+			return -EINVAL;
+		}
+	} else {
+		/*
+		 * To be as close as possible to 400 kHz, the parent clk
+		 * frequency should be between a minimum value of 6 MHz and a
+		 * maximum value of 46 MHz due to hardware limitation
+		 */
+		if (freq < STM32F4_I2C_MIN_FAST_FREQ ||
+		    freq > STM32F4_I2C_MAX_FREQ) {
+			dev_err(i2c_dev->dev,
+				"bad parent clk freq for fast mode\n");
+			return -EINVAL;
+		}
+	}
+
+	cr2 |= STM32F4_I2C_CR2_FREQ(freq);
+	writel_relaxed(cr2, i2c_dev->base + STM32F4_I2C_CR2);
+
+	return 0;
+}
+
+static void stm32f4_i2c_set_rise_time(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 freq = DIV_ROUND_UP(i2c_dev->parent_rate, HZ_TO_MHZ);
+	u32 trise;
+
+	/*
+	 * These bits must be programmed with the maximum SCL rise time given in
+	 * the I2C bus specification, incremented by 1.
+	 *
+	 * In standard mode, the maximum allowed SCL rise time is 1000 ns.
+	 * If, in the I2C_CR2 register, the value of FREQ[5:0] bits is equal to
+	 * 0x08 so period = 125 ns therefore the TRISE[5:0] bits must be
+	 * programmed with 0x9. (1000 ns / 125 ns + 1)
+	 * So, for I2C standard mode TRISE = FREQ[5:0] + 1
+	 *
+	 * In fast mode, the maximum allowed SCL rise time is 300 ns.
+	 * If, in the I2C_CR2 register, the value of FREQ[5:0] bits is equal to
+	 * 0x08 so period = 125 ns therefore the TRISE[5:0] bits must be
+	 * programmed with 0x3. (300 ns / 125 ns + 1)
+	 * So, for I2C fast mode TRISE = FREQ[5:0] * 300 / 1000 + 1
+	 *
+	 * Function stm32f4_i2c_set_periph_clk_freq made sure that parent rate
+	 * is not higher than 46 MHz . As a result trise is at most 4 bits wide
+	 * and so fits into the TRISE bits [5:0].
+	 */
+	if (i2c_dev->speed == STM32F4_I2C_SPEED_STANDARD)
+		trise = freq + 1;
+	else
+		trise = freq * 3 / 10 + 1;
+
+	writel_relaxed(STM32F4_I2C_TRISE_VALUE(trise),
+		       i2c_dev->base + STM32F4_I2C_TRISE);
+}
+
+static void stm32f4_i2c_set_speed_mode(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 val;
+	u32 ccr = 0;
+
+	if (i2c_dev->speed == STM32F4_I2C_SPEED_STANDARD) {
+		/*
+		 * In standard mode:
+		 * t_scl_high = t_scl_low = CCR * I2C parent clk period
+		 * So to reach 100 kHz, we have:
+		 * CCR = I2C parent rate / 100 kHz >> 1
+		 *
+		 * For example with parent rate = 2 MHz:
+		 * CCR = 2000000 / (100000 << 1) = 10
+		 * t_scl_high = t_scl_low = 10 * (1 / 2000000) = 5000 ns
+		 * t_scl_high + t_scl_low = 10000 ns so 100 kHz is reached
+		 *
+		 * Function stm32f4_i2c_set_periph_clk_freq made sure that
+		 * parent rate is not higher than 46 MHz . As a result val
+		 * is at most 8 bits wide and so fits into the CCR bits [11:0].
+		 */
+		val = i2c_dev->parent_rate / (100000 << 1);
+	} else {
+		/*
+		 * In fast mode, we compute CCR with duty = 0 as with low
+		 * frequencies we are not able to reach 400 kHz.
+		 * In that case:
+		 * t_scl_high = CCR * I2C parent clk period
+		 * t_scl_low = 2 * CCR * I2C parent clk period
+		 * So, CCR = I2C parent rate / (400 kHz * 3)
+		 *
+		 * For example with parent rate = 6 MHz:
+		 * CCR = 6000000 / (400000 * 3) = 5
+		 * t_scl_high = 5 * (1 / 6000000) = 833 ns > 600 ns
+		 * t_scl_low = 2 * 5 * (1 / 6000000) = 1667 ns > 1300 ns
+		 * t_scl_high + t_scl_low = 2500 ns so 400 kHz is reached
+		 *
+		 * Function stm32f4_i2c_set_periph_clk_freq made sure that
+		 * parent rate is not higher than 46 MHz . As a result val
+		 * is at most 6 bits wide and so fits into the CCR bits [11:0].
+		 */
+		val = DIV_ROUND_UP(i2c_dev->parent_rate, 400000 * 3);
+
+		/* Select Fast mode */
+		ccr |= STM32F4_I2C_CCR_FS;
+	}
+
+	ccr |= STM32F4_I2C_CCR_CCR(val);
+	writel_relaxed(ccr, i2c_dev->base + STM32F4_I2C_CCR);
+}
+
+/**
+ * stm32f4_i2c_hw_config() - Prepare I2C block
+ * @i2c_dev: Controller's private data
+ */
+static int stm32f4_i2c_hw_config(struct stm32f4_i2c_dev *i2c_dev)
+{
+	int ret;
+
+	ret = stm32f4_i2c_set_periph_clk_freq(i2c_dev);
+	if (ret)
+		return ret;
+
+	stm32f4_i2c_set_rise_time(i2c_dev);
+
+	stm32f4_i2c_set_speed_mode(i2c_dev);
+
+	/* Enable I2C */
+	writel_relaxed(STM32F4_I2C_CR1_PE, i2c_dev->base + STM32F4_I2C_CR1);
+
+	return 0;
+}
+
+static int stm32f4_i2c_wait_free_bus(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 status;
+	int ret;
+
+	ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F4_I2C_SR2,
+					 status,
+					 !(status & STM32F4_I2C_SR2_BUSY),
+					 10, 1000);
+	if (ret) {
+		dev_dbg(i2c_dev->dev, "bus not free\n");
+		ret = -EBUSY;
+	}
+
+	return ret;
+}
+
+/**
+ * stm32f4_i2c_write_ byte() - Write a byte in the data register
+ * @i2c_dev: Controller's private data
+ * @byte: Data to write in the register
+ */
+static void stm32f4_i2c_write_byte(struct stm32f4_i2c_dev *i2c_dev, u8 byte)
+{
+	writel_relaxed(byte, i2c_dev->base + STM32F4_I2C_DR);
+}
+
+/**
+ * stm32f4_i2c_write_msg() - Fill the data register in write mode
+ * @i2c_dev: Controller's private data
+ *
+ * This function fills the data register with I2C transfer buffer
+ */
+static void stm32f4_i2c_write_msg(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+
+	stm32f4_i2c_write_byte(i2c_dev, *msg->buf++);
+	msg->count--;
+}
+
+static void stm32f4_i2c_read_msg(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	u32 rbuf;
+
+	rbuf = readl_relaxed(i2c_dev->base + STM32F4_I2C_DR);
+	*msg->buf++ = rbuf;
+	msg->count--;
+}
+
+static void stm32f4_i2c_terminate_xfer(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	stm32f4_i2c_disable_irq(i2c_dev);
+
+	reg = i2c_dev->base + STM32F4_I2C_CR1;
+	if (msg->stop)
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_STOP);
+	else
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_START);
+
+	complete(&i2c_dev->complete);
+}
+
+/**
+ * stm32f4_i2c_handle_write() - Handle FIFO empty interrupt in case of write
+ * @i2c_dev: Controller's private data
+ */
+static void stm32f4_i2c_handle_write(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	if (msg->count) {
+		stm32f4_i2c_write_msg(i2c_dev);
+		if (!msg->count) {
+			/*
+			 * Disable buffer interrupts for RX not empty and TX
+			 * empty events
+			 */
+			stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_ITBUFEN);
+		}
+	} else {
+		stm32f4_i2c_terminate_xfer(i2c_dev);
+	}
+}
+
+/**
+ * stm32f4_i2c_handle_read() - Handle FIFO empty interrupt in case of read
+ * @i2c_dev: Controller's private data
+ *
+ * This function is called when a new data is received in data register
+ */
+static void stm32f4_i2c_handle_read(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	switch (msg->count) {
+	case 1:
+		stm32f4_i2c_disable_irq(i2c_dev);
+		stm32f4_i2c_read_msg(i2c_dev);
+		complete(&i2c_dev->complete);
+		break;
+	/*
+	 * For 2-byte reception, 3-byte reception and for Data N-2, N-1 and N
+	 * for N-byte reception with N > 3, we do not have to read the data
+	 * register when RX not empty event occurs as we have to wait for byte
+	 * transferred finished event before reading data.
+	 * So, here we just disable buffer interrupt in order to avoid another
+	 * system preemption due to RX not empty event.
+	 */
+	case 2:
+	case 3:
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_ITBUFEN);
+		break;
+	/*
+	 * For N byte reception with N > 3 we directly read data register
+	 * until N-2 data.
+	 */
+	default:
+		stm32f4_i2c_read_msg(i2c_dev);
+	}
+}
+
+/**
+ * stm32f4_i2c_handle_rx_done() - Handle byte transfer finished interrupt
+ * in case of read
+ * @i2c_dev: Controller's private data
+ *
+ * This function is called when a new data is received in the shift register
+ * but data register has not been read yet.
+ */
+static void stm32f4_i2c_handle_rx_done(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg;
+	u32 mask;
+	int i;
+
+	switch (msg->count) {
+	case 2:
+		/*
+		 * In order to correctly send the Stop or Repeated Start
+		 * condition on the I2C bus, the STOP/START bit has to be set
+		 * before reading the last two bytes (data N-1 and N).
+		 * After that, we could read the last two bytes, disable
+		 * remaining interrupts and notify the end of xfer to the
+		 * client
+		 */
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		if (msg->stop)
+			stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_STOP);
+		else
+			stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_START);
+
+		for (i = 2; i > 0; i--)
+			stm32f4_i2c_read_msg(i2c_dev);
+
+		reg = i2c_dev->base + STM32F4_I2C_CR2;
+		mask = STM32F4_I2C_CR2_ITEVTEN | STM32F4_I2C_CR2_ITERREN;
+		stm32f4_i2c_clr_bits(reg, mask);
+
+		complete(&i2c_dev->complete);
+		break;
+	case 3:
+		/*
+		 * In order to correctly generate the NACK pulse after the last
+		 * received data byte, we have to enable NACK before reading N-2
+		 * data
+		 */
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_ACK);
+		stm32f4_i2c_read_msg(i2c_dev);
+		break;
+	default:
+		stm32f4_i2c_read_msg(i2c_dev);
+	}
+}
+
+/**
+ * stm32f4_i2c_handle_rx_addr() - Handle address matched interrupt in case of
+ * master receiver
+ * @i2c_dev: Controller's private data
+ */
+static void stm32f4_i2c_handle_rx_addr(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	u32 cr1;
+
+	switch (msg->count) {
+	case 0:
+		stm32f4_i2c_terminate_xfer(i2c_dev);
+
+		/* Clear ADDR flag */
+		readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+		break;
+	case 1:
+		/*
+		 * Single byte reception:
+		 * Enable NACK and reset POS (Acknowledge position).
+		 * Then, clear ADDR flag and set STOP or RepSTART.
+		 * In that way, the NACK and STOP or RepStart pulses will be
+		 * sent as soon as the byte will be received in shift register
+		 */
+		cr1 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR1);
+		cr1 &= ~(STM32F4_I2C_CR1_ACK | STM32F4_I2C_CR1_POS);
+		writel_relaxed(cr1, i2c_dev->base + STM32F4_I2C_CR1);
+
+		readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+
+		if (msg->stop)
+			cr1 |= STM32F4_I2C_CR1_STOP;
+		else
+			cr1 |= STM32F4_I2C_CR1_START;
+		writel_relaxed(cr1, i2c_dev->base + STM32F4_I2C_CR1);
+		break;
+	case 2:
+		/*
+		 * 2-byte reception:
+		 * Enable NACK, set POS (NACK position) and clear ADDR flag.
+		 * In that way, NACK will be sent for the next byte which will
+		 * be received in the shift register instead of the current
+		 * one.
+		 */
+		cr1 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR1);
+		cr1 &= ~STM32F4_I2C_CR1_ACK;
+		cr1 |= STM32F4_I2C_CR1_POS;
+		writel_relaxed(cr1, i2c_dev->base + STM32F4_I2C_CR1);
+
+		readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+		break;
+
+	default:
+		/*
+		 * N-byte reception:
+		 * Enable ACK, reset POS (ACK postion) and clear ADDR flag.
+		 * In that way, ACK will be sent as soon as the current byte
+		 * will be received in the shift register
+		 */
+		cr1 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR1);
+		cr1 |= STM32F4_I2C_CR1_ACK;
+		cr1 &= ~STM32F4_I2C_CR1_POS;
+		writel_relaxed(cr1, i2c_dev->base + STM32F4_I2C_CR1);
+
+		readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+		break;
+	}
+}
+
+/**
+ * stm32f4_i2c_isr_event() - Interrupt routine for I2C bus event
+ * @irq: interrupt number
+ * @data: Controller's private data
+ */
+static irqreturn_t stm32f4_i2c_isr_event(int irq, void *data)
+{
+	struct stm32f4_i2c_dev *i2c_dev = data;
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	u32 possible_status = STM32F4_I2C_SR1_ITEVTEN_MASK;
+	u32 status, ien, event, cr2;
+
+	cr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
+	ien = cr2 & STM32F4_I2C_CR2_IRQ_MASK;
+
+	/* Update possible_status if buffer interrupt is enabled */
+	if (ien & STM32F4_I2C_CR2_ITBUFEN)
+		possible_status |= STM32F4_I2C_SR1_ITBUFEN_MASK;
+
+	status = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR1);
+	event = status & possible_status;
+	if (!event) {
+		dev_dbg(i2c_dev->dev,
+			"spurious evt irq (status=0x%08x, ien=0x%08x)\n",
+			status, ien);
+		return IRQ_NONE;
+	}
+
+	/* Start condition generated */
+	if (event & STM32F4_I2C_SR1_SB)
+		stm32f4_i2c_write_byte(i2c_dev, msg->addr);
+
+	/* I2C Address sent */
+	if (event & STM32F4_I2C_SR1_ADDR) {
+		if (msg->addr & I2C_M_RD)
+			stm32f4_i2c_handle_rx_addr(i2c_dev);
+		else
+			readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+
+		/*
+		 * Enable buffer interrupts for RX not empty and TX empty
+		 * events
+		 */
+		cr2 |= STM32F4_I2C_CR2_ITBUFEN;
+		writel_relaxed(cr2, i2c_dev->base + STM32F4_I2C_CR2);
+	}
+
+	/* TX empty */
+	if ((event & STM32F4_I2C_SR1_TXE) && !(msg->addr & I2C_M_RD))
+		stm32f4_i2c_handle_write(i2c_dev);
+
+	/* RX not empty */
+	if ((event & STM32F4_I2C_SR1_RXNE) && (msg->addr & I2C_M_RD))
+		stm32f4_i2c_handle_read(i2c_dev);
+
+	/*
+	 * The BTF (Byte Transfer finished) event occurs when:
+	 * - in reception : a new byte is received in the shift register
+	 * but the previous byte has not been read yet from data register
+	 * - in transmission: a new byte should be sent but the data register
+	 * has not been written yet
+	 */
+	if (event & STM32F4_I2C_SR1_BTF) {
+		if (msg->addr & I2C_M_RD)
+			stm32f4_i2c_handle_rx_done(i2c_dev);
+		else
+			stm32f4_i2c_handle_write(i2c_dev);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * stm32f4_i2c_isr_error() - Interrupt routine for I2C bus error
+ * @irq: interrupt number
+ * @data: Controller's private data
+ */
+static irqreturn_t stm32f4_i2c_isr_error(int irq, void *data)
+{
+	struct stm32f4_i2c_dev *i2c_dev = data;
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg;
+	u32 status;
+
+	status = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR1);
+
+	/* Arbitration lost */
+	if (status & STM32F4_I2C_SR1_ARLO) {
+		status &= ~STM32F4_I2C_SR1_ARLO;
+		writel_relaxed(status, i2c_dev->base + STM32F4_I2C_SR1);
+		msg->result = -EAGAIN;
+	}
+
+	/*
+	 * Acknowledge failure:
+	 * In master transmitter mode a Stop must be generated by software
+	 */
+	if (status & STM32F4_I2C_SR1_AF) {
+		if (!(msg->addr & I2C_M_RD)) {
+			reg = i2c_dev->base + STM32F4_I2C_CR1;
+			stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_STOP);
+		}
+		status &= ~STM32F4_I2C_SR1_AF;
+		writel_relaxed(status, i2c_dev->base + STM32F4_I2C_SR1);
+		msg->result = -EIO;
+	}
+
+	/* Bus error */
+	if (status & STM32F4_I2C_SR1_BERR) {
+		status &= ~STM32F4_I2C_SR1_BERR;
+		writel_relaxed(status, i2c_dev->base + STM32F4_I2C_SR1);
+		msg->result = -EIO;
+	}
+
+	stm32f4_i2c_disable_irq(i2c_dev);
+	complete(&i2c_dev->complete);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * stm32f4_i2c_xfer_msg() - Transfer a single I2C message
+ * @i2c_dev: Controller's private data
+ * @msg: I2C message to transfer
+ * @is_first: first message of the sequence
+ * @is_last: last message of the sequence
+ */
+static int stm32f4_i2c_xfer_msg(struct stm32f4_i2c_dev *i2c_dev,
+				struct i2c_msg *msg, bool is_first,
+				bool is_last)
+{
+	struct stm32f4_i2c_msg *f4_msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR1;
+	unsigned long timeout;
+	u32 mask;
+	int ret;
+
+	f4_msg->addr = i2c_8bit_addr_from_msg(msg);
+	f4_msg->buf = msg->buf;
+	f4_msg->count = msg->len;
+	f4_msg->result = 0;
+	f4_msg->stop = is_last;
+
+	reinit_completion(&i2c_dev->complete);
+
+	/* Enable events and errors interrupts */
+	mask = STM32F4_I2C_CR2_ITEVTEN | STM32F4_I2C_CR2_ITERREN;
+	stm32f4_i2c_set_bits(i2c_dev->base + STM32F4_I2C_CR2, mask);
+
+	if (is_first) {
+		ret = stm32f4_i2c_wait_free_bus(i2c_dev);
+		if (ret)
+			return ret;
+
+		/* START generation */
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_START);
+	}
+
+	timeout = wait_for_completion_timeout(&i2c_dev->complete,
+					      i2c_dev->adap.timeout);
+	ret = f4_msg->result;
+
+	if (!timeout)
+		ret = -ETIMEDOUT;
+
+	return ret;
+}
+
+/**
+ * stm32f4_i2c_xfer() - Transfer combined I2C message
+ * @i2c_adap: Adapter pointer to the controller
+ * @msgs: Pointer to data to be written.
+ * @num: Number of messages to be executed
+ */
+static int stm32f4_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[],
+			    int num)
+{
+	struct stm32f4_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
+	int ret, i;
+
+	ret = clk_enable(i2c_dev->clk);
+	if (ret) {
+		dev_err(i2c_dev->dev, "Failed to enable clock\n");
+		return ret;
+	}
+
+	for (i = 0; i < num && !ret; i++)
+		ret = stm32f4_i2c_xfer_msg(i2c_dev, &msgs[i], i == 0,
+					   i == num - 1);
+
+	clk_disable(i2c_dev->clk);
+
+	return (ret < 0) ? ret : num;
+}
+
+static u32 stm32f4_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm stm32f4_i2c_algo = {
+	.master_xfer = stm32f4_i2c_xfer,
+	.functionality = stm32f4_i2c_func,
+};
+
+static int stm32f4_i2c_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct stm32f4_i2c_dev *i2c_dev;
+	struct resource *res;
+	u32 irq_event, irq_error, clk_rate;
+	struct i2c_adapter *adap;
+	struct reset_control *rst;
+	int ret;
+
+	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
+	if (!i2c_dev)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	i2c_dev->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(i2c_dev->base))
+		return PTR_ERR(i2c_dev->base);
+
+	irq_event = irq_of_parse_and_map(np, 0);
+	if (!irq_event) {
+		dev_err(&pdev->dev, "IRQ event missing or invalid\n");
+		return -EINVAL;
+	}
+
+	irq_error = irq_of_parse_and_map(np, 1);
+	if (!irq_error) {
+		dev_err(&pdev->dev, "IRQ error missing or invalid\n");
+		return -EINVAL;
+	}
+
+	i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(i2c_dev->clk)) {
+		dev_err(&pdev->dev, "Error: Missing controller clock\n");
+		return PTR_ERR(i2c_dev->clk);
+	}
+	ret = clk_prepare_enable(i2c_dev->clk);
+	if (ret) {
+		dev_err(i2c_dev->dev, "Failed to prepare_enable clock\n");
+		return ret;
+	}
+
+	rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(rst)) {
+		dev_err(&pdev->dev, "Error: Missing controller reset\n");
+		ret = PTR_ERR(rst);
+		goto clk_free;
+	}
+	reset_control_assert(rst);
+	udelay(2);
+	reset_control_deassert(rst);
+
+	i2c_dev->speed = STM32F4_I2C_SPEED_STANDARD;
+	ret = of_property_read_u32(np, "clock-frequency", &clk_rate);
+	if (!ret && clk_rate >= 400000)
+		i2c_dev->speed = STM32F4_I2C_SPEED_FAST;
+
+	i2c_dev->dev = &pdev->dev;
+
+	ret = devm_request_irq(&pdev->dev, irq_event, stm32f4_i2c_isr_event, 0,
+			       pdev->name, i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq event %i\n",
+			irq_event);
+		goto clk_free;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq_error, stm32f4_i2c_isr_error, 0,
+			       pdev->name, i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq error %i\n",
+			irq_error);
+		goto clk_free;
+	}
+
+	ret = stm32f4_i2c_hw_config(i2c_dev);
+	if (ret)
+		goto clk_free;
+
+	adap = &i2c_dev->adap;
+	i2c_set_adapdata(adap, i2c_dev);
+	snprintf(adap->name, sizeof(adap->name), "STM32 I2C(%pa)", &res->start);
+	adap->owner = THIS_MODULE;
+	adap->timeout = 2 * HZ;
+	adap->retries = 0;
+	adap->algo = &stm32f4_i2c_algo;
+	adap->dev.parent = &pdev->dev;
+	adap->dev.of_node = pdev->dev.of_node;
+
+	init_completion(&i2c_dev->complete);
+
+	ret = i2c_add_adapter(adap);
+	if (ret)
+		goto clk_free;
+
+	platform_set_drvdata(pdev, i2c_dev);
+
+	clk_disable(i2c_dev->clk);
+
+	dev_info(i2c_dev->dev, "STM32F4 I2C driver registered\n");
+
+	return 0;
+
+clk_free:
+	clk_disable_unprepare(i2c_dev->clk);
+	return ret;
+}
+
+static int stm32f4_i2c_remove(struct platform_device *pdev)
+{
+	struct stm32f4_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&i2c_dev->adap);
+
+	clk_unprepare(i2c_dev->clk);
+
+	return 0;
+}
+
+static const struct of_device_id stm32f4_i2c_match[] = {
+	{ .compatible = "st,stm32f4-i2c", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32f4_i2c_match);
+
+static struct platform_driver stm32f4_i2c_driver = {
+	.driver = {
+		.name = "stm32f4-i2c",
+		.of_match_table = stm32f4_i2c_match,
+	},
+	.probe = stm32f4_i2c_probe,
+	.remove = stm32f4_i2c_remove,
+};
+
+module_platform_driver(stm32f4_i2c_driver);
+
+MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32F4 I2C driver");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

^ permalink raw reply related

* [PATCH v10 3/5] ARM: dts: stm32: Add I2C1 support for STM32F429 SoC
From: M'boumba Cedric Madianga @ 2017-01-19 13:25 UTC (permalink / raw)
  To: wsa, robh+dt, mcoquelin.stm32, alexandre.torgue, linus.walleij,
	patrice.chotard, linux, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, u.kleine-koenig
  Cc: M'boumba Cedric Madianga
In-Reply-To: <1484832316-5594-1-git-send-email-cedric.madianga@gmail.com>

This patch adds I2C1 support for STM32F429 SoC

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 arch/arm/boot/dts/stm32f429.dtsi | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/arm/boot/dts/stm32f429.dtsi b/arch/arm/boot/dts/stm32f429.dtsi
index e4dae0e..5b063e9 100644
--- a/arch/arm/boot/dts/stm32f429.dtsi
+++ b/arch/arm/boot/dts/stm32f429.dtsi
@@ -48,6 +48,7 @@
 #include "skeleton.dtsi"
 #include "armv7-m.dtsi"
 #include <dt-bindings/pinctrl/stm32f429-pinfunc.h>
+#include <dt-bindings/mfd/stm32f4-rcc.h>
 
 / {
 	clocks {
@@ -153,6 +154,18 @@
 			status = "disabled";
 		};
 
+		i2c1: i2c@40005400 {
+			compatible = "st,stm32f4-i2c";
+			reg = <0x40005400 0x400>;
+			interrupts = <31>,
+				     <32>;
+			resets = <&rcc STM32F4_APB1_RESET(I2C1)>;
+			clocks = <&rcc 0 STM32F4_APB1_CLOCK(I2C1)>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "disabled";
+		};
+
 		usart7: serial@40007800 {
 			compatible = "st,stm32-usart", "st,stm32-uart";
 			reg = <0x40007800 0x400>;
@@ -355,6 +368,16 @@
 					slew-rate = <2>;
 				};
 			};
+
+			i2c1_pins_b: i2c1@0 {
+				pins {
+					pinmux = <STM32F429_PB9_FUNC_I2C1_SDA>,
+						 <STM32F429_PB6_FUNC_I2C1_SCL>;
+					bias-disable;
+					drive-open-drain;
+					slew-rate = <3>;
+				};
+			};
 		};
 
 		rcc: rcc@40023810 {
-- 
1.9.1

^ permalink raw reply related

* [PATCH v10 4/5] ARM: dts: stm32: Add I2C1 support for STM32429 eval board
From: M'boumba Cedric Madianga @ 2017-01-19 13:25 UTC (permalink / raw)
  To: wsa, robh+dt, mcoquelin.stm32, alexandre.torgue, linus.walleij,
	patrice.chotard, linux, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, u.kleine-koenig
  Cc: M'boumba Cedric Madianga
In-Reply-To: <1484832316-5594-1-git-send-email-cedric.madianga@gmail.com>

This patch adds I2C1 instance support for STM32x9I-Eval board.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 arch/arm/boot/dts/stm32429i-eval.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/stm32429i-eval.dts b/arch/arm/boot/dts/stm32429i-eval.dts
index 76f7206..c943539 100644
--- a/arch/arm/boot/dts/stm32429i-eval.dts
+++ b/arch/arm/boot/dts/stm32429i-eval.dts
@@ -146,3 +146,9 @@
 	pinctrl-names = "default";
 	status = "okay";
 };
+
+&i2c1 {
+	pinctrl-0 = <&i2c1_pins_b>;
+	pinctrl-names = "default";
+	status = "okay";
+};
-- 
1.9.1

^ permalink raw reply related

* [PATCH v10 5/5] ARM: configs: stm32: Add I2C support for STM32 defconfig
From: M'boumba Cedric Madianga @ 2017-01-19 13:25 UTC (permalink / raw)
  To: wsa, robh+dt, mcoquelin.stm32, alexandre.torgue, linus.walleij,
	patrice.chotard, linux, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, u.kleine-koenig
  Cc: M'boumba Cedric Madianga
In-Reply-To: <1484832316-5594-1-git-send-email-cedric.madianga@gmail.com>

This patch adds I2C support for STM32 default configuration

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 arch/arm/configs/stm32_defconfig | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
index 5a72d69..323d2a3 100644
--- a/arch/arm/configs/stm32_defconfig
+++ b/arch/arm/configs/stm32_defconfig
@@ -47,6 +47,9 @@ CONFIG_SERIAL_NONSTANDARD=y
 CONFIG_SERIAL_STM32=y
 CONFIG_SERIAL_STM32_CONSOLE=y
 # CONFIG_HW_RANDOM is not set
+CONFIG_I2C=y
+CONFIG_I2C_CHARDEV=y
+CONFIG_I2C_STM32F4=y
 # CONFIG_HWMON is not set
 # CONFIG_USB_SUPPORT is not set
 CONFIG_NEW_LEDS=y
-- 
1.9.1

^ permalink raw reply related

* [PATCH v4 00/14] ARM: da850-lcdk: add SATA support
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, Bartosz Golaszewski, linux-kernel, linux-arm-kernel,
	devicetree

This series contains all the changes necessary to make SATA work on
the da850-lcdk board.

The first patch adds DT bindings for the ahci-da850 driver.

The second enables relevant modules in davinci_all_defconfig.

Patches 03/14-06/14 modify the way the clocks are handled regarding
SATA on the da850 platform. We modify the ahci driver to retrieve
the clock via con_id and model the external SATA oscillator as
a real clock.

Patches 07/14-11/14 extend the ahci-da850 driver. Add DT support,
implement workarounds necessary to make SATA work on the da850-lcdk
board and un-hardcode the external clock multiplier.

Last two patches add device tree changes required to probe the
driver.

v1 -> v2:
- dropped patch 04/10 - replaced with local changes in the
  ahci-da850 driver
- added comments explaining the workaround in ahci softreset
- s/0x218000/218000 in the sata DT node label
- added patches chaning the way clocks are handled in the da850 SATA
  code both in arch/ and in the ahci driver
- dropped the clock multiplier property in the DT bindings in favor
  of using struct clk to pass the refclk rate to the driver
- minor tweaks in commit messages

v2 -> v3:
- dropped the clocks property from the ahci-da850 DT binding
- dropped patch 12/14 (SATA pinmux settings)
- dropped an outdated fragment from the commit message in patch 14/14
- s/get_clk()/clk_get()/
- s/connector id/connection id/
- stopped using __div64_32() after noticing that it sometimes produces
  invalid results
- removed the default MPY value from ahci-da850
- registered SATA refclk for board file boot mode as well

v3 -> v4:
- added a patch removing the no longer needed BUG_ON() from
  da850_register_sata()
- fixed indents

Bartosz Golaszewski (14):
  devicetree: bindings: add bindings for ahci-da850
  ARM: davinci_all_defconfig: enable SATA modules
  ARM: davinci: add a clock lookup entry for the SATA clock
  sata: ahci-da850: get the sata clock using a connection id
  ARM: davinci: da850: add con_id for the SATA clock
  ARM: davinci: da850: model the SATA refclk
  sata: ahci-da850: add device tree match table
  sata: ahci-da850: implement a workaround for the softreset quirk
  sata: ahci: export ahci_do_hardreset() locally
  sata: ahci-da850: add a workaround for controller instability
  sata: ahci-da850: un-hardcode the MPY bits
  ARM: dts: da850: add the SATA node
  ARM: dts: da850-lcdk: enable the SATA node
  ARM: davinci: remove BUG_ON() from da850_register_sata()

 .../devicetree/bindings/ata/ahci-da850.txt         |  15 ++
 arch/arm/boot/dts/da850-lcdk.dts                   |   4 +
 arch/arm/boot/dts/da850.dtsi                       |   6 +
 arch/arm/configs/davinci_all_defconfig             |   2 +
 arch/arm/mach-davinci/da850.c                      |   2 +-
 arch/arm/mach-davinci/da8xx-dt.c                   |   9 ++
 arch/arm/mach-davinci/devices-da8xx.c              |  30 +++-
 arch/arm/mach-davinci/include/mach/da8xx.h         |   1 +
 drivers/ata/ahci.h                                 |   3 +
 drivers/ata/ahci_da850.c                           | 175 +++++++++++++++++++--
 drivers/ata/libahci.c                              |  18 ++-
 11 files changed, 240 insertions(+), 25 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/ata/ahci-da850.txt

-- 
2.9.3

^ permalink raw reply

* [PATCH v4 01/14] devicetree: bindings: add bindings for ahci-da850
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, Bartosz Golaszewski, linux-kernel, linux-arm-kernel,
	devicetree
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

Add DT bindings for the TI DA850 AHCI SATA controller.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 Documentation/devicetree/bindings/ata/ahci-da850.txt | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ata/ahci-da850.txt

diff --git a/Documentation/devicetree/bindings/ata/ahci-da850.txt b/Documentation/devicetree/bindings/ata/ahci-da850.txt
new file mode 100644
index 0000000..fd90662
--- /dev/null
+++ b/Documentation/devicetree/bindings/ata/ahci-da850.txt
@@ -0,0 +1,15 @@
+Device tree binding for the TI DA850 AHCI SATA Controller
+---------------------------------------------------------
+
+Required properties:
+  - compatible: must be "ti,da850-ahci"
+  - reg: physical base addresses and sizes of the controller's register areas
+  - interrupts: interrupt specifier (refer to the interrupt binding)
+
+Example:
+
+	sata: ahci@218000 {
+		compatible = "ti,da850-ahci";
+		reg = <0x218000 0x2000>, <0x22c018 0x4>;
+		interrupts = <67>;
+	};
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 02/14] ARM: davinci_all_defconfig: enable SATA modules
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, Bartosz Golaszewski, linux-kernel, linux-arm-kernel,
	devicetree
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

Add the da850-ahci driver to davinci defconfig.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/configs/davinci_all_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/davinci_all_defconfig b/arch/arm/configs/davinci_all_defconfig
index 8806754..a1b9c58 100644
--- a/arch/arm/configs/davinci_all_defconfig
+++ b/arch/arm/configs/davinci_all_defconfig
@@ -78,6 +78,8 @@ CONFIG_IDE=m
 CONFIG_BLK_DEV_PALMCHIP_BK3710=m
 CONFIG_SCSI=m
 CONFIG_BLK_DEV_SD=m
+CONFIG_ATA=m
+CONFIG_AHCI_DA850=m
 CONFIG_NETDEVICES=y
 CONFIG_NETCONSOLE=y
 CONFIG_TUN=m
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 03/14] ARM: davinci: add a clock lookup entry for the SATA clock
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, devicetree, linux-kernel, linux-arm-kernel,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

This entry is needed for the ahci driver to get a functional clock.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/mach-davinci/da8xx-dt.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/mach-davinci/da8xx-dt.c b/arch/arm/mach-davinci/da8xx-dt.c
index 9ee44da..b83e5d1 100644
--- a/arch/arm/mach-davinci/da8xx-dt.c
+++ b/arch/arm/mach-davinci/da8xx-dt.c
@@ -42,6 +42,7 @@ static struct of_dev_auxdata da850_auxdata_lookup[] __initdata = {
 	OF_DEV_AUXDATA("ti,da830-ohci", 0x01e25000, "ohci-da8xx", NULL),
 	OF_DEV_AUXDATA("ti,da830-musb", 0x01e00000, "musb-da8xx", NULL),
 	OF_DEV_AUXDATA("ti,da830-usb-phy", 0x01c1417c, "da8xx-usb-phy", NULL),
+	OF_DEV_AUXDATA("ti,da850-ahci", 0x01e18000, "ahci_da850", NULL),
 	{}
 };
 
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 04/14] sata: ahci-da850: get the sata clock using a connection id
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, Bartosz Golaszewski, linux-kernel, linux-arm-kernel,
	devicetree
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

In preparation for using two clocks in the driver (the sysclk2-based
clock and the external REFCLK), check if we got a functional clock
after calling ahci_platform_get_resources(). If not, retry calling
clk_get() with con_id specified.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/ata/ahci_da850.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 267a3d3..8cfdc86 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -71,12 +71,28 @@ static int ahci_da850_probe(struct platform_device *pdev)
 	struct ahci_host_priv *hpriv;
 	struct resource *res;
 	void __iomem *pwrdn_reg;
+	struct clk *clk;
 	int rc;
 
 	hpriv = ahci_platform_get_resources(pdev);
 	if (IS_ERR(hpriv))
 		return PTR_ERR(hpriv);
 
+	/*
+	 * Internally ahci_platform_get_resources() calls clk_get(dev, NULL)
+	 * when trying to obtain the first clock. This SATA controller uses
+	 * two clocks for which we specify two connection ids. If we don't
+	 * have a clock at this point - call clk_get() again with
+	 * con_id = "sata".
+	 */
+	if (!hpriv->clks[0]) {
+		clk = clk_get(dev, "sata");
+		if (IS_ERR(clk))
+			return PTR_ERR(clk);
+
+		hpriv->clks[0] = clk;
+	}
+
 	rc = ahci_platform_enable_resources(hpriv);
 	if (rc)
 		return rc;
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 05/14] ARM: davinci: da850: add con_id for the SATA clock
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, devicetree, linux-kernel, linux-arm-kernel,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

The ahci-da850 SATA driver is now capable of retrieving clocks by
con_id. Add the connection id for the sysclk2-derived SATA clock.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/mach-davinci/da850.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
index 1d873d1..dbf1daa 100644
--- a/arch/arm/mach-davinci/da850.c
+++ b/arch/arm/mach-davinci/da850.c
@@ -571,7 +571,7 @@ static struct clk_lookup da850_clks[] = {
 	CLK("spi_davinci.0",	NULL,		&spi0_clk),
 	CLK("spi_davinci.1",	NULL,		&spi1_clk),
 	CLK("vpif",		NULL,		&vpif_clk),
-	CLK("ahci_da850",		NULL,		&sata_clk),
+	CLK("ahci_da850",	"sata",		&sata_clk),
 	CLK("davinci-rproc.0",	NULL,		&dsp_clk),
 	CLK(NULL,		NULL,		&ehrpwm_clk),
 	CLK("ehrpwm.0",		"fck",		&ehrpwm0_clk),
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 06/14] ARM: davinci: da850: model the SATA refclk
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, Bartosz Golaszewski, linux-kernel, linux-arm-kernel,
	devicetree
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

Register a dummy clock modelling the external SATA oscillator for
da850 (both DT and board file mode).

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/mach-davinci/da8xx-dt.c           |  8 ++++++++
 arch/arm/mach-davinci/devices-da8xx.c      | 29 +++++++++++++++++++++++++++++
 arch/arm/mach-davinci/include/mach/da8xx.h |  1 +
 3 files changed, 38 insertions(+)

diff --git a/arch/arm/mach-davinci/da8xx-dt.c b/arch/arm/mach-davinci/da8xx-dt.c
index b83e5d1..55342ca 100644
--- a/arch/arm/mach-davinci/da8xx-dt.c
+++ b/arch/arm/mach-davinci/da8xx-dt.c
@@ -50,6 +50,9 @@ static struct of_dev_auxdata da850_auxdata_lookup[] __initdata = {
 
 static void __init da850_init_machine(void)
 {
+	/* All existing boards use 100MHz SATA refclkpn */
+	static const unsigned long sata_refclkpn = 100 * 1000 * 1000;
+
 	int ret;
 
 	ret = da8xx_register_usb20_phy_clk(false);
@@ -61,6 +64,11 @@ static void __init da850_init_machine(void)
 		pr_warn("%s: registering USB 1.1 PHY clock failed: %d",
 			__func__, ret);
 
+	ret = da850_register_sata_refclk(sata_refclkpn);
+	if (ret)
+		pr_warn("%s: registering SATA REFCLK failed: %d",
+			__func__, ret);
+
 	of_platform_default_populate(NULL, da850_auxdata_lookup, NULL);
 	davinci_pm_init();
 }
diff --git a/arch/arm/mach-davinci/devices-da8xx.c b/arch/arm/mach-davinci/devices-da8xx.c
index c2457b3..cfceb32 100644
--- a/arch/arm/mach-davinci/devices-da8xx.c
+++ b/arch/arm/mach-davinci/devices-da8xx.c
@@ -24,6 +24,7 @@
 #include <mach/common.h>
 #include <mach/time.h>
 #include <mach/da8xx.h>
+#include <mach/clock.h>
 #include "cpuidle.h"
 #include "sram.h"
 
@@ -1023,6 +1024,28 @@ int __init da8xx_register_spi_bus(int instance, unsigned num_chipselect)
 }
 
 #ifdef CONFIG_ARCH_DAVINCI_DA850
+static struct clk sata_refclk = {
+	.name		= "sata_refclk",
+	.set_rate	= davinci_simple_set_rate,
+};
+
+static struct clk_lookup sata_refclk_lookup =
+		CLK("ahci_da850", "refclk", &sata_refclk);
+
+int __init da850_register_sata_refclk(int rate)
+{
+	int ret;
+
+	sata_refclk.rate = rate;
+	ret = clk_register(&sata_refclk);
+	if (ret)
+		return ret;
+
+	clkdev_add(&sata_refclk_lookup);
+
+	return 0;
+}
+
 static struct resource da850_sata_resources[] = {
 	{
 		.start	= DA850_SATA_BASE,
@@ -1055,9 +1078,15 @@ static struct platform_device da850_sata_device = {
 
 int __init da850_register_sata(unsigned long refclkpn)
 {
+	int ret;
+
 	/* please see comment in drivers/ata/ahci_da850.c */
 	BUG_ON(refclkpn != 100 * 1000 * 1000);
 
+	ret = da850_register_sata_refclk(refclkpn);
+	if (ret)
+		return ret;
+
 	return platform_device_register(&da850_sata_device);
 }
 #endif
diff --git a/arch/arm/mach-davinci/include/mach/da8xx.h b/arch/arm/mach-davinci/include/mach/da8xx.h
index 85ff218..7e46422 100644
--- a/arch/arm/mach-davinci/include/mach/da8xx.h
+++ b/arch/arm/mach-davinci/include/mach/da8xx.h
@@ -95,6 +95,7 @@ int da8xx_register_usb11(struct da8xx_ohci_root_hub *pdata);
 int da8xx_register_usb_refclkin(int rate);
 int da8xx_register_usb20_phy_clk(bool use_usb_refclkin);
 int da8xx_register_usb11_phy_clk(bool use_usb_refclkin);
+int da850_register_sata_refclk(int rate);
 int da8xx_register_emac(void);
 int da8xx_register_uio_pruss(void);
 int da8xx_register_lcdc(struct da8xx_lcdc_platform_data *pdata);
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 07/14] sata: ahci-da850: add device tree match table
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, Bartosz Golaszewski, linux-kernel, linux-arm-kernel,
	devicetree
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

We're using device tree for da850-lcdk. Add the match table to allow
to probe the driver.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/ata/ahci_da850.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 8cfdc86..7f5328f 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -121,11 +121,18 @@ static int ahci_da850_probe(struct platform_device *pdev)
 static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend,
 			 ahci_platform_resume);
 
+static const struct of_device_id ahci_da850_of_match[] = {
+	{ .compatible = "ti,da850-ahci", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ahci_da850_of_match);
+
 static struct platform_driver ahci_da850_driver = {
 	.probe = ahci_da850_probe,
 	.remove = ata_platform_remove_one,
 	.driver = {
 		.name = DRV_NAME,
+		.of_match_table = ahci_da850_of_match,
 		.pm = &ahci_da850_pm_ops,
 	},
 };
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 08/14] sata: ahci-da850: implement a workaround for the softreset quirk
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, Bartosz Golaszewski, linux-kernel, linux-arm-kernel,
	devicetree
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

There's an issue with the da850 SATA controller: if port multiplier
support is compiled in, but we're connecting the drive directly to
the SATA port on the board, the drive can't be detected.

To make SATA work on the da850-lcdk board: first try to softreset
with pmp - if the operation fails with -EBUSY, retry without pmp.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/ata/ahci_da850.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 7f5328f..11dd87e 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -54,11 +54,42 @@ static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
 	writel(val, ahci_base + SATA_P0PHYCR_REG);
 }
 
+static int ahci_da850_softreset(struct ata_link *link,
+				unsigned int *class, unsigned long deadline)
+{
+	int pmp, ret;
+
+	pmp = sata_srst_pmp(link);
+
+	/*
+	 * There's an issue with the SATA controller on da850 SoCs: if we
+	 * enable Port Multiplier support, but the drive is connected directly
+	 * to the board, it can't be detected. As a workaround: if PMP is
+	 * enabled, we first call ahci_do_softreset() and pass it the result of
+	 * sata_srst_pmp(). If this call fails, we retry with pmp = 0.
+	 */
+	ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
+	if (pmp && ret == -EBUSY)
+		return ahci_do_softreset(link, class, 0,
+					 deadline, ahci_check_ready);
+
+	return ret;
+}
+
+static struct ata_port_operations ahci_da850_port_ops = {
+	.inherits = &ahci_platform_ops,
+	.softreset = ahci_da850_softreset,
+	/*
+	 * No need to override .pmp_softreset - it's only used for actual
+	 * PMP-enabled ports.
+	 */
+};
+
 static const struct ata_port_info ahci_da850_port_info = {
 	.flags		= AHCI_FLAG_COMMON,
 	.pio_mask	= ATA_PIO4,
 	.udma_mask	= ATA_UDMA6,
-	.port_ops	= &ahci_platform_ops,
+	.port_ops	= &ahci_da850_port_ops,
 };
 
 static struct scsi_host_template ahci_platform_sht = {
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 09/14] sata: ahci: export ahci_do_hardreset() locally
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, devicetree, linux-kernel, linux-arm-kernel,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

We need a way to retrieve the information about the online state of
the link in the ahci-da850 driver.

Create a new function: ahci_do_hardreset() which is called from
ahci_hardreset() for backwards compatibility, but has an additional
argument: 'online' - which can be used to check if the link is online
after this function returns.

The new routine will be used in the ahci-da850 driver to avoid code
duplication when implementing a workaround for tha da850 SATA
controller quirk/instability.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/ata/ahci.h    |  3 +++
 drivers/ata/libahci.c | 18 +++++++++++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 0cc08f8..5db6ab2 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -398,6 +398,9 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class,
 		      int pmp, unsigned long deadline,
 		      int (*check_ready)(struct ata_link *link));
 
+int ahci_do_hardreset(struct ata_link *link, unsigned int *class,
+		      unsigned long deadline, bool *online);
+
 unsigned int ahci_qc_issue(struct ata_queued_cmd *qc);
 int ahci_stop_engine(struct ata_port *ap);
 void ahci_start_fis_rx(struct ata_port *ap);
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index ee7db31..3159f9e 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1519,8 +1519,8 @@ static int ahci_pmp_retry_softreset(struct ata_link *link, unsigned int *class,
 	return rc;
 }
 
-static int ahci_hardreset(struct ata_link *link, unsigned int *class,
-			  unsigned long deadline)
+int ahci_do_hardreset(struct ata_link *link, unsigned int *class,
+		      unsigned long deadline, bool *online)
 {
 	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
 	struct ata_port *ap = link->ap;
@@ -1528,7 +1528,6 @@ static int ahci_hardreset(struct ata_link *link, unsigned int *class,
 	struct ahci_host_priv *hpriv = ap->host->private_data;
 	u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
 	struct ata_taskfile tf;
-	bool online;
 	int rc;
 
 	DPRINTK("ENTER\n");
@@ -1540,17 +1539,26 @@ static int ahci_hardreset(struct ata_link *link, unsigned int *class,
 	tf.command = ATA_BUSY;
 	ata_tf_to_fis(&tf, 0, 0, d2h_fis);
 
-	rc = sata_link_hardreset(link, timing, deadline, &online,
+	rc = sata_link_hardreset(link, timing, deadline, online,
 				 ahci_check_ready);
 
 	hpriv->start_engine(ap);
 
-	if (online)
+	if (*online)
 		*class = ahci_dev_classify(ap);
 
 	DPRINTK("EXIT, rc=%d, class=%u\n", rc, *class);
 	return rc;
 }
+EXPORT_SYMBOL_GPL(ahci_do_hardreset);
+
+static int ahci_hardreset(struct ata_link *link, unsigned int *class,
+			  unsigned long deadline)
+{
+	bool online;
+
+	return ahci_do_hardreset(link, class, deadline, &online);
+}
 
 static void ahci_postreset(struct ata_link *link, unsigned int *class)
 {
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 10/14] sata: ahci-da850: add a workaround for controller instability
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, devicetree, linux-kernel, linux-arm-kernel,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

We have a use case with the da850 SATA controller where at PLL0
frequency of 456MHz (needed to properly service the LCD controller)
the chip becomes unstable and the hardreset operation is ignored the
first time 50% of times.

The sata core driver already retries to resume the link because some
controllers ignore writes to the SControl register, but just retrying
the resume operation doesn't work - we need to issue he phy/wake reset
again to make it work.

Reimplement ahci_hardreset() in the driver and poke the controller a
couple times before really giving up.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/ata/ahci_da850.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 11dd87e..0b2b1a4 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -16,7 +16,8 @@
 #include <linux/ahci_platform.h>
 #include "ahci.h"
 
-#define DRV_NAME "ahci_da850"
+#define DRV_NAME		"ahci_da850"
+#define HARDRESET_RETRIES	5
 
 /* SATA PHY Control Register offset from AHCI base */
 #define SATA_P0PHYCR_REG	0x178
@@ -76,6 +77,29 @@ static int ahci_da850_softreset(struct ata_link *link,
 	return ret;
 }
 
+static int ahci_da850_hardreset(struct ata_link *link,
+				unsigned int *class, unsigned long deadline)
+{
+	int ret, retry = HARDRESET_RETRIES;
+	bool online;
+
+	/*
+	 * In order to correctly service the LCD controller of the da850 SoC,
+	 * we increased the PLL0 frequency to 456MHz from the default 300MHz.
+	 *
+	 * This made the SATA controller unstable and the hardreset operation
+	 * does not always succeed the first time. Before really giving up to
+	 * bring up the link, retry the reset a couple times.
+	 */
+	do {
+		ret = ahci_do_hardreset(link, class, deadline, &online);
+		if (online)
+			return ret;
+	} while (retry--);
+
+	return ret;
+}
+
 static struct ata_port_operations ahci_da850_port_ops = {
 	.inherits = &ahci_platform_ops,
 	.softreset = ahci_da850_softreset,
@@ -83,6 +107,8 @@ static struct ata_port_operations ahci_da850_port_ops = {
 	 * No need to override .pmp_softreset - it's only used for actual
 	 * PMP-enabled ports.
 	 */
+	.hardreset = ahci_da850_hardreset,
+	.pmp_hardreset = ahci_da850_hardreset,
 };
 
 static const struct ata_port_info ahci_da850_port_info = {
-- 
2.9.3

^ permalink raw reply related

* [PATCH v4 11/14] sata: ahci-da850: un-hardcode the MPY bits
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>

All platforms using this driver now register the SATA refclk. Remove
the hardcoded default value from the driver and instead read the rate
of the external clock and calculate the required MPY value from it.

Signed-off-by: Bartosz Golaszewski <bgolaszewski-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
---
 drivers/ata/ahci_da850.c | 91 ++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 76 insertions(+), 15 deletions(-)

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 0b2b1a4..9ed404d 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -29,17 +29,8 @@
 #define SATA_PHY_TXSWING(x)	((x) << 19)
 #define SATA_PHY_ENPLL(x)	((x) << 31)
 
-/*
- * The multiplier needed for 1.5GHz PLL output.
- *
- * NOTE: This is currently hardcoded to be suitable for 100MHz crystal
- * frequency (which is used by DA850 EVM board) and may need to be changed
- * if you would like to use this driver on some other board.
- */
-#define DA850_SATA_CLK_MULTIPLIER	7
-
 static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
-			    void __iomem *ahci_base)
+			    void __iomem *ahci_base, u32 mpy)
 {
 	unsigned int val;
 
@@ -48,13 +39,61 @@ static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
 	val &= ~BIT(0);
 	writel(val, pwrdn_reg);
 
-	val = SATA_PHY_MPY(DA850_SATA_CLK_MULTIPLIER + 1) | SATA_PHY_LOS(1) |
-	      SATA_PHY_RXCDR(4) | SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) |
-	      SATA_PHY_ENPLL(1);
+	val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) |
+	      SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1);
 
 	writel(val, ahci_base + SATA_P0PHYCR_REG);
 }
 
+static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate)
+{
+	u32 pll_output = 1500000000, needed;
+
+	/*
+	 * We need to determine the value of the multiplier (MPY) bits.
+	 * In order to include the 12.5 multiplier we need to first divide
+	 * the refclk rate by ten.
+	 *
+	 * __div64_32() turned out to be unreliable, sometimes returning
+	 * false results.
+	 */
+	WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10");
+	needed = pll_output / (refclk_rate / 10);
+
+	/*
+	 * What we have now is (multiplier * 10).
+	 *
+	 * Let's determine the actual register value we need to write.
+	 */
+
+	switch (needed) {
+	case 50:
+		return 0x1;
+	case 60:
+		return 0x2;
+	case 80:
+		return 0x4;
+	case 100:
+		return 0x5;
+	case 120:
+		return 0x6;
+	case 125:
+		return 0x7;
+	case 150:
+		return 0x8;
+	case 200:
+		return 0x9;
+	case 250:
+		return 0xa;
+	default:
+		/*
+		 * We should have divided evenly - if not, return an invalid
+		 * value.
+		 */
+		return 0;
+	}
+}
+
 static int ahci_da850_softreset(struct ata_link *link,
 				unsigned int *class, unsigned long deadline)
 {
@@ -126,9 +165,10 @@ static int ahci_da850_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct ahci_host_priv *hpriv;
-	struct resource *res;
 	void __iomem *pwrdn_reg;
+	struct resource *res;
 	struct clk *clk;
+	u32 mpy;
 	int rc;
 
 	hpriv = ahci_platform_get_resources(pdev);
@@ -150,6 +190,27 @@ static int ahci_da850_probe(struct platform_device *pdev)
 		hpriv->clks[0] = clk;
 	}
 
+	/*
+	 * The second clock used by ahci-da850 is the external REFCLK. If we
+	 * didn't get it from ahci_platform_get_resources(), let's try to
+	 * specify the con_id in clk_get().
+	 */
+	if (!hpriv->clks[1]) {
+		clk = clk_get(dev, "refclk");
+		if (IS_ERR(clk)) {
+			dev_err(dev, "unable to obtain the reference clock");
+			return -ENODEV;
+		} else {
+			hpriv->clks[1] = clk;
+		}
+	}
+
+	mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1]));
+	if (mpy == 0) {
+		dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy);
+		return -EINVAL;
+	}
+
 	rc = ahci_platform_enable_resources(hpriv);
 	if (rc)
 		return rc;
@@ -162,7 +223,7 @@ static int ahci_da850_probe(struct platform_device *pdev)
 	if (!pwrdn_reg)
 		goto disable_resources;
 
-	da850_sata_init(dev, pwrdn_reg, hpriv->mmio);
+	da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy);
 
 	rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info,
 				     &ahci_platform_sht);
-- 
2.9.3

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply related

* [PATCH v4 12/14] ARM: dts: da850: add the SATA node
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, devicetree, linux-kernel, linux-arm-kernel,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

Add the SATA node to the da850 device tree.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index 104155d..e9bf30e 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -403,6 +403,12 @@
 			phy-names = "usb-phy";
 			status = "disabled";
 		};
+		sata: ahci@218000 {
+			compatible = "ti,da850-ahci";
+			reg = <0x218000 0x2000>, <0x22c018 0x4>;
+			interrupts = <67>;
+			status = "disabled";
+		};
 		mdio: mdio@224000 {
 			compatible = "ti,davinci_mdio";
 			#address-cells = <1>;
-- 
2.9.3


^ permalink raw reply related

* [PATCH v4 13/14] ARM: dts: da850-lcdk: enable the SATA node
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, devicetree, linux-kernel, linux-arm-kernel,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

Enable the SATA node for da850-lcdk. We omit the pinctrl property on
purpose - the muxed SATA pins are not hooked up to anything
SATA-related on the lcdk.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850-lcdk.dts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
index afcb482..fbeee3c 100644
--- a/arch/arm/boot/dts/da850-lcdk.dts
+++ b/arch/arm/boot/dts/da850-lcdk.dts
@@ -105,6 +105,10 @@
 	status = "okay";
 };
 
+&sata {
+	status = "okay";
+};
+
 &mdio {
 	pinctrl-names = "default";
 	pinctrl-0 = <&mdio_pins>;
-- 
2.9.3


^ permalink raw reply related

* [PATCH v4 14/14] ARM: davinci: remove BUG_ON() from da850_register_sata()
From: Bartosz Golaszewski @ 2017-01-19 13:29 UTC (permalink / raw)
  To: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King, David Lechner
  Cc: linux-ide, devicetree, linux-kernel, linux-arm-kernel,
	Bartosz Golaszewski
In-Reply-To: <1484832588-18413-1-git-send-email-bgolaszewski@baylibre.com>

The ahci driver now supports other refclk clock rates.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/mach-davinci/devices-da8xx.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm/mach-davinci/devices-da8xx.c b/arch/arm/mach-davinci/devices-da8xx.c
index cfceb32..7cf529f 100644
--- a/arch/arm/mach-davinci/devices-da8xx.c
+++ b/arch/arm/mach-davinci/devices-da8xx.c
@@ -1080,9 +1080,6 @@ int __init da850_register_sata(unsigned long refclkpn)
 {
 	int ret;
 
-	/* please see comment in drivers/ata/ahci_da850.c */
-	BUG_ON(refclkpn != 100 * 1000 * 1000);
-
 	ret = da850_register_sata_refclk(refclkpn);
 	if (ret)
 		return ret;
-- 
2.9.3

^ permalink raw reply related

* Re: [PATCH v10 2/5] i2c: Add STM32F4 I2C driver
From: Uwe Kleine-König @ 2017-01-19 13:31 UTC (permalink / raw)
  To: M'boumba Cedric Madianga
  Cc: wsa, robh+dt, mcoquelin.stm32, alexandre.torgue, linus.walleij,
	patrice.chotard, linux, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel
In-Reply-To: <1484832316-5594-3-git-send-email-cedric.madianga@gmail.com>

On Thu, Jan 19, 2017 at 02:25:13PM +0100, M'boumba Cedric Madianga wrote:
> This patch adds support for the STM32F4 I2C controller.
> 
> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Thanks
Uwe

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

^ permalink raw reply

* Re: [PATCH v3 06/13] ARM: davinci: da850: model the SATA refclk
From: Bartosz Golaszewski @ 2017-01-19 13:31 UTC (permalink / raw)
  To: David Lechner
  Cc: Kevin Hilman, Sekhar Nori, Patrick Titiano, Michael Turquette,
	Tejun Heo, Rob Herring, Mark Rutland, Russell King,
	linux-ide-u79uwXL29TY76Z2rM5mHXA, linux-devicetree, LKML, arm-soc
In-Reply-To: <ff4deee6-9700-fff3-be96-0ad2f008914b-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>

2017-01-18 18:26 GMT+01:00 David Lechner <david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>:
> On 01/18/2017 07:19 AM, Bartosz Golaszewski wrote:
>>
>>  int __init da850_register_sata(unsigned long refclkpn)
>>  {
>> +       int ret;
>> +
>>         /* please see comment in drivers/ata/ahci_da850.c */
>>         BUG_ON(refclkpn != 100 * 1000 * 1000);
>
>
> This BUG_ON() should be removed since the sata driver can now handle other
> clock frequencies.
>

I did that in a separate patch coming after the ahci changes to keep
the series bisectable.

Thanks,
Bartosz Golaszewski
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply

* [PATCH 0/7] Add support for triggered buffer mode to STM32 ADC
From: Fabrice Gasnier @ 2017-01-19 13:34 UTC (permalink / raw)
  To: jic23, linux, robh+dt, linux-arm-kernel, devicetree, linux-kernel
  Cc: linux-iio, mark.rutland, mcoquelin.stm32, alexandre.torgue, lars,
	knaack.h, pmeerw, fabrice.gasnier, benjamin.gaignard,
	benjamin.gaignard

The following patches add support for triggered buffer mode.
These are based on top of "Add PWM and IIO timer drivers for STM32"
series. Reference:
https://lkml.org/lkml/2017/1/18/588

STM32 ADC, can use either interrupts or DMA to collect data.
Either timer trigger output (TRGO) or PWM can be used as trigger source.
This patchset has been tested on STM32F429 eval board.

- Example to enable timer1 PWM:
cd /sys/devices/platform/soc/40010000.timers/40010000.timers:pwm/pwm/pwmchip4/
echo 0 > export # timer 1 channel 1
echo 1000000 > pwm0/period # 1000Hz
echo 500000 > pwm0/duty_cycle
echo 1 > pwm0/enable

- Example to enable timer3 TRGO:
cd /sys/bus/iio/devices/
cat trigger6/name 
tim1_ch1
cat trigger0/name 
tim3_trgo
echo 1000 > trigger0/sampling_frequency

- Example to configure STM32ADC in triggered buffer mode, with timer1 PWM
  or timer3 TRGO:
cd /sys/bus/iio/devices/iio\:device0
echo tim1_ch1 > trigger/current_trigger
OR: echo tim3_trgo > trigger/current_trigger
echo 1 > scan_elements/in_voltage8_en
echo 1 > buffer/enable

Fabrice Gasnier (7):
  iio: adc: stm32: add support for triggered buffer mode
  iio: adc: stm32: Enable use of stm32 timer triggers
  iio: adc: stm32: add trigger polarity extended attribute
  Documentation: dt: iio: stm32-adc: optional dma support
  iio: adc: stm32: add optional dma support
  ARM: dts: stm32: Enable dma by default on stm32f4 adc
  ARM: dts: stm32: Enable pwm1 and pwm3 for stm32f469-eval

 .../devicetree/bindings/iio/adc/st,stm32-adc.txt   |   7 +
 arch/arm/boot/dts/stm32429i-eval.dts               |  28 +
 arch/arm/boot/dts/stm32f429.dtsi                   |   6 +
 drivers/iio/adc/Kconfig                            |   6 +
 drivers/iio/adc/stm32-adc-core.c                   |   1 +
 drivers/iio/adc/stm32-adc-core.h                   |   2 +
 drivers/iio/adc/stm32-adc.c                        | 643 ++++++++++++++++++++-
 7 files changed, 690 insertions(+), 3 deletions(-)

-- 
1.9.1

^ permalink raw reply


This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox