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[PATCH v3 0/5] Introduce at91_adc8xx driver

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  [PATCH v3 0/5] Introduce at91_adc8xx driver Ludovic Desroches <ludovic.desroches@atmel.com> - 2016-01-14 16:40 +0100
    [PATCH v3 2/5] MAINTAINERS: add entry for Atmel ADC 8xx driver Ludovic Desroches <ludovic.desroches@atmel.com> - 2016-01-14 16:40 +0100
      [RESEND PATCH v3 2/5] MAINTAINERS: add entry for Atmel SAMA5D2 ADC driver Ludovic Desroches <ludovic.desroches@atmel.com> - 2016-01-15 10:00 +0100
    [PATCH v3 4/5] ARM: at91/dt: sama5d2 Xplained: enable the adc device Ludovic Desroches <ludovic.desroches@atmel.com> - 2016-01-14 16:40 +0100
    [PATCH v3 1/5] iio:adc:at91_adc8xx: introduce new atmel adc driver Ludovic Desroches <ludovic.desroches@atmel.com> - 2016-01-14 16:40 +0100
    [PATCH v3 5/5] ARM: at91/defconfig: add sama5d2 adc support in sama5_defconfig Ludovic Desroches <ludovic.desroches@atmel.com> - 2016-01-14 16:50 +0100

#1309422 — [PATCH v3 0/5] Introduce at91_adc8xx driver

Hi,

This is the very basic support for the adc introduced with the SAMA5D2 SoC
family.

The goal is to provide something to the user as soon as possible instead of
waiting for a full featured driver.

Only unsigned conversions on a software tigger are supported. Next steps are
signed conversions, differential channels, hardware triggers, dma support,
touchscreen support, and others.

Changes:
- v3:
  - Driver file renaming.
  - Syntax cleanup.
  - Sampling frequency accessed through read/write_raw.
  - Cleanup in the IRQ handler.
- v2:
  - Cleanup thanks to Peter Meerwald-Stadler comments (add prefix for macros,
    remove useless stuff, etc).
  - Move parameters relative to the SoC to the device tree (min/max sampling
    rate and startup time).
  - Use sysfs to configure the sampling frequency.
  - vddana supply is no more optionnal.
  - No change for irq since I am not sure it will simplify the code (interrupt
    is cleared when reading channel conversion result). Jonathan, tell me if
    I need to rework this part.


Ludovic Desroches (5):
  iio:adc:at91_adc8xx: introduce new atmel adc driver
  MAINTAINERS: add entry for Atmel ADC 8xx driver
  ARM: at91/dt: sama5d2: add adc device
  ARM: at91/dt: sama5d2 Xplained: enable the adc device
  ARM: at91/defconfig: add sama5d2 adc support in sama5_defconfig

 .../bindings/iio/adc/at91-sama5d2_adc.txt          |  28 ++
 MAINTAINERS                                        |   6 +
 arch/arm/boot/dts/at91-sama5d2_xplained.dts        |  22 +
 arch/arm/boot/dts/sama5d2.dtsi                     |  18 +-
 arch/arm/configs/sama5_defconfig                   |   1 +
 drivers/iio/adc/Kconfig                            |  11 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/at91-sama5d2_adc.c                 | 509 +++++++++++++++++++++
 8 files changed, 590 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/at91-sama5d2_adc.txt
 create mode 100644 drivers/iio/adc/at91-sama5d2_adc.c

-- 
2.5.0

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#1309428 — [PATCH v3 2/5] MAINTAINERS: add entry for Atmel ADC 8xx driver

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
---
 MAINTAINERS | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index dac3be0..113900c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1951,6 +1951,12 @@ M:	Nicolas Ferre <nicolas.ferre@atmel.com>
 S:	Supported
 F:	drivers/tty/serial/atmel_serial.c
 
+ATMEL ADC 8xx DRIVER
+M:	Ludovic Desroches <ludovic.desroches@atmel.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+F:	drivers/iio/adc/at91_adc8xx.c
+
 ATMEL Audio ALSA driver
 M:	Nicolas Ferre <nicolas.ferre@atmel.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
-- 
2.5.0

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#1309965 — [RESEND PATCH v3 2/5] MAINTAINERS: add entry for Atmel SAMA5D2 ADC driver

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
---

I have forgotten to update this patch with the new name of the driver.

 MAINTAINERS | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index dac3be0..144422c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1951,6 +1951,12 @@ M:	Nicolas Ferre <nicolas.ferre@atmel.com>
 S:	Supported
 F:	drivers/tty/serial/atmel_serial.c
 
+ATMEL SAMA5D2 ADC DRIVER
+M:	Ludovic Desroches <ludovic.desroches@atmel.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+F:	drivers/iio/adc/at91-sama5d2_adc.c
+
 ATMEL Audio ALSA driver
 M:	Nicolas Ferre <nicolas.ferre@atmel.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
-- 
2.5.0

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#1309433 — [PATCH v3 4/5] ARM: at91/dt: sama5d2 Xplained: enable the adc device

Enable the adc on the sama5d2 Xplained board.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
---
 arch/arm/boot/dts/at91-sama5d2_xplained.dts | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/arch/arm/boot/dts/at91-sama5d2_xplained.dts b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
index 77ddff0..c3102a0 100644
--- a/arch/arm/boot/dts/at91-sama5d2_xplained.dts
+++ b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
@@ -261,7 +261,29 @@
 				};
 			};
 
+			adc: adc@fc030000 {
+				vddana-supply = <&vdd_3v3_lp_reg>;
+				vref-supply = <&vdd_3v3_lp_reg>;
+				pinctrl-names = "default";
+				pinctrl-0 = <&pinctrl_adc_default>;
+				status = "okay";
+			};
+
 			pinctrl@fc038000 {
+				/*
+				 * There is no real pinmux for ADC, if the pin
+				 * is not requested by another peripheral then
+				 * the muxing is done when channel is enabled.
+				 * Requesting pins for ADC is GPIO is
+				 * encouraged to prevent conflicts and to
+				 * disable bias in order to be in the same
+				 * state when the pin is not muxed to the adc.
+				 */
+				pinctrl_adc_default: adc_default {
+					pinmux = <PIN_PD23__GPIO>;
+					bias-disable;
+				};
+
 				pinctrl_flx0_default: flx0_default {
 					pinmux = <PIN_PB28__FLEXCOM0_IO0>,
 						 <PIN_PB29__FLEXCOM0_IO1>;
-- 
2.5.0

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#1309435 — [PATCH v3 1/5] iio:adc:at91_adc8xx: introduce new atmel adc driver

This driver supports the new version of the Atmel ADC device introduced
with the SAMA5D2 SoC family.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../bindings/iio/adc/at91-sama5d2_adc.txt          |  28 ++
 drivers/iio/adc/Kconfig                            |  11 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/at91-sama5d2_adc.c                 | 509 +++++++++++++++++++++
 4 files changed, 549 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/at91-sama5d2_adc.txt
 create mode 100644 drivers/iio/adc/at91-sama5d2_adc.c

diff --git a/Documentation/devicetree/bindings/iio/adc/at91-sama5d2_adc.txt b/Documentation/devicetree/bindings/iio/adc/at91-sama5d2_adc.txt
new file mode 100644
index 0000000..3223684
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/at91-sama5d2_adc.txt
@@ -0,0 +1,28 @@
+* AT91 SAMA5D2 Analog to Digital Converter (ADC)
+
+Required properties:
+  - compatible: Should be "atmel,sama5d2-adc".
+  - reg: Should contain ADC registers location and length.
+  - interrupts: Should contain the IRQ line for the ADC.
+  - clocks: phandle to device clock.
+  - clock-names: Must be "adc_clk".
+  - vref-supply: Supply used as reference for conversions.
+  - vddana-supply: Supply for the adc device.
+  - atmel,min-sample-rate-hz: Minimum sampling rate, it depends on SoC.
+  - atmel,max-sample-rate-hz: Maximum sampling rate, it depends on SoC.
+  - atmel,startup-time-ms: Startup time expressed in ms, it depends on SoC.
+
+Example:
+
+adc: adc@fc030000 {
+	compatible = "atmel,sama5d2-adc";
+	reg = <0xfc030000 0x100>;
+	interrupts = <40 IRQ_TYPE_LEVEL_HIGH 7>;
+	clocks = <&adc_clk>;
+	clock-names = "adc_clk";
+	atmel,min-sample-rate-hz = <200000>;
+	atmel,max-sample-rate-hz = <20000000>;
+	atmel,startup-time-ms = <4>;
+	vddana-supply = <&vdd_3v3_lp_reg>;
+	vref-supply = <&vdd_3v3_lp_reg>;
+}
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 605ff42..f57b4ea 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -131,6 +131,17 @@ config AT91_ADC
 	  To compile this driver as a module, choose M here: the module will be
 	  called at91_adc.
 
+config AT91_SAMA5D2_ADC
+	tristate "Atmel AT91 SAMA5D2 ADC"
+	depends on ARCH_AT91
+	depends on INPUT
+	help
+	  Say yes here to build support for Atmel SAMA5D2 ADC which is
+	  available on SAMA5D2 SoC family.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called at91-sama5d2_adc.
+
 config AXP288_ADC
 	tristate "X-Powers AXP288 ADC driver"
 	depends on MFD_AXP20X
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 6435780..fb57e12 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_AD7793) += ad7793.o
 obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
+obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
 obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
new file mode 100644
index 0000000..ecb2d90
--- /dev/null
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -0,0 +1,509 @@
+/*
+ * Atmel ADC driver for SAMA5D2 devices and compatible.
+ *
+ * Copyright (C) 2015 Atmel,
+ *               2015 Ludovic Desroches <ludovic.desroches@atmel.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/regulator/consumer.h>
+
+/* Control Register */
+#define AT91_SAMA5D2_CR		0x00
+/* Software Reset */
+#define	AT91_SAMA5D2_CR_SWRST		BIT(0)
+/* Start Conversion */
+#define	AT91_SAMA5D2_CR_START		BIT(1)
+/* Touchscreen Calibration */
+#define	AT91_SAMA5D2_CR_TSCALIB		BIT(2)
+/* Comparison Restart */
+#define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
+
+/* Mode Register */
+#define AT91_SAMA5D2_MR		0x04
+/* Trigger Selection */
+#define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
+/* ADTRG */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG0	0
+/* TIOA0 */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG1	1
+/* TIOA1 */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG2	2
+/* TIOA2 */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG3	3
+/* PWM event line 0 */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG4	4
+/* PWM event line 1 */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG5	5
+/* TIOA3 */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG6	6
+/* RTCOUT0 */
+#define	AT91_SAMA5D2_MR_TRGSEL_TRIG7	7
+/* Sleep Mode */
+#define	AT91_SAMA5D2_MR_SLEEP		BIT(5)
+/* Fast Wake Up */
+#define	AT91_SAMA5D2_MR_FWUP		BIT(6)
+/* Prescaler Rate Selection */
+#define	AT91_SAMA5D2_MR_PRESCAL(v)	((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET)
+#define	AT91_SAMA5D2_MR_PRESCAL_OFFSET	8
+#define	AT91_SAMA5D2_MR_PRESCAL_MAX	0xff
+/* Startup Time */
+#define	AT91_SAMA5D2_MR_STARTUP(v)	((v) << 16)
+/* Analog Change */
+#define	AT91_SAMA5D2_MR_ANACH		BIT(23)
+/* Tracking Time */
+#define	AT91_SAMA5D2_MR_TRACKTIM(v)	((v) << 24)
+#define	AT91_SAMA5D2_MR_TRACKTIM_MAX	0xff
+/* Transfer Time */
+#define	AT91_SAMA5D2_MR_TRANSFER(v)	((v) << 28)
+#define	AT91_SAMA5D2_MR_TRANSFER_MAX	0x3
+/* Use Sequence Enable */
+#define	AT91_SAMA5D2_MR_USEQ		BIT(31)
+
+/* Channel Sequence Register 1 */
+#define AT91_SAMA5D2_SEQR1	0x08
+/* Channel Sequence Register 2 */
+#define AT91_SAMA5D2_SEQR2	0x0c
+/* Channel Enable Register */
+#define AT91_SAMA5D2_CHER	0x10
+/* Channel Disable Register */
+#define AT91_SAMA5D2_CHDR	0x14
+/* Channel Status Register */
+#define AT91_SAMA5D2_CHSR	0x18
+/* Last Converted Data Register */
+#define AT91_SAMA5D2_LCDR	0x20
+/* Interrupt Enable Register */
+#define AT91_SAMA5D2_IER		0x24
+/* Interrupt Disable Register */
+#define AT91_SAMA5D2_IDR		0x28
+/* Interrupt Mask Register */
+#define AT91_SAMA5D2_IMR		0x2c
+/* Interrupt Status Register */
+#define AT91_SAMA5D2_ISR		0x30
+/* Last Channel Trigger Mode Register */
+#define AT91_SAMA5D2_LCTMR	0x34
+/* Last Channel Compare Window Register */
+#define AT91_SAMA5D2_LCCWR	0x38
+/* Overrun Status Register */
+#define AT91_SAMA5D2_OVER	0x3c
+/* Extended Mode Register */
+#define AT91_SAMA5D2_EMR		0x40
+/* Compare Window Register */
+#define AT91_SAMA5D2_CWR		0x44
+/* Channel Gain Register */
+#define AT91_SAMA5D2_CGR		0x48
+/* Channel Offset Register */
+#define AT91_SAMA5D2_COR		0x4c
+/* Channel Data Register 0 */
+#define AT91_SAMA5D2_CDR0	0x50
+/* Analog Control Register */
+#define AT91_SAMA5D2_ACR		0x94
+/* Touchscreen Mode Register */
+#define AT91_SAMA5D2_TSMR	0xb0
+/* Touchscreen X Position Register */
+#define AT91_SAMA5D2_XPOSR	0xb4
+/* Touchscreen Y Position Register */
+#define AT91_SAMA5D2_YPOSR	0xb8
+/* Touchscreen Pressure Register */
+#define AT91_SAMA5D2_PRESSR	0xbc
+/* Trigger Register */
+#define AT91_SAMA5D2_TRGR	0xc0
+/* Correction Select Register */
+#define AT91_SAMA5D2_COSR	0xd0
+/* Correction Value Register */
+#define AT91_SAMA5D2_CVR		0xd4
+/* Channel Error Correction Register */
+#define AT91_SAMA5D2_CECR	0xd8
+/* Write Protection Mode Register */
+#define AT91_SAMA5D2_WPMR	0xe4
+/* Write Protection Status Register */
+#define AT91_SAMA5D2_WPSR	0xe8
+/* Version Register */
+#define AT91_SAMA5D2_VERSION	0xfc
+
+#define AT91_AT91_SAMA5D2_CHAN(num, addr)				\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.channel = num,						\
+		.address = addr,					\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = 12,					\
+		},							\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
+		.datasheet_name = "CH"#num,				\
+		.indexed = 1,						\
+	}
+
+#define at91_adc_readl(st, reg)		readl_relaxed(st->base + reg)
+#define at91_adc_writel(st, reg, val)	writel_relaxed(val, st->base + reg)
+
+struct at91_adc_soc_info {
+	unsigned			startup_time;
+	unsigned			min_sample_rate;
+	unsigned			max_sample_rate;
+};
+
+struct at91_adc_state {
+	void __iomem			*base;
+	int				irq;
+	struct clk			*per_clk;
+	struct regulator		*reg;
+	struct regulator		*vref;
+	u32				vref_uv;
+	const struct iio_chan_spec	*chan;
+	bool				conversion_done;
+	u32				conversion_value;
+	struct at91_adc_soc_info	soc_info;
+	wait_queue_head_t		wq_data_available;
+	/*
+	 * lock to prevent concurrent 'single conversion' requests through
+	 * sysfs.
+	 */
+	struct mutex			lock;
+};
+
+static const struct iio_chan_spec at91_adc_channels[] = {
+	AT91_AT91_SAMA5D2_CHAN(0, 0x50),
+	AT91_AT91_SAMA5D2_CHAN(1, 0x54),
+	AT91_AT91_SAMA5D2_CHAN(2, 0x58),
+	AT91_AT91_SAMA5D2_CHAN(3, 0x5c),
+	AT91_AT91_SAMA5D2_CHAN(4, 0x60),
+	AT91_AT91_SAMA5D2_CHAN(5, 0x64),
+	AT91_AT91_SAMA5D2_CHAN(6, 0x68),
+	AT91_AT91_SAMA5D2_CHAN(7, 0x6c),
+	AT91_AT91_SAMA5D2_CHAN(8, 0x70),
+	AT91_AT91_SAMA5D2_CHAN(9, 0x74),
+	AT91_AT91_SAMA5D2_CHAN(10, 0x78),
+	AT91_AT91_SAMA5D2_CHAN(11, 0x7c),
+};
+
+static unsigned at91_adc_startup_time(unsigned startup_time_min,
+				      unsigned adc_clk_khz)
+{
+	const unsigned startup_lookup[] = {
+		  0,   8,  16,  24,
+		 64,  80,  96, 112,
+		512, 576, 640, 704,
+		768, 832, 896, 960
+		};
+	unsigned ticks_min, i;
+
+	/*
+	 * Since the adc frequency is checked before, there is no reason
+	 * to not meet the startup time constraint.
+	 */
+
+	ticks_min = startup_time_min * adc_clk_khz / 1000;
+	for (i = 0; i < ARRAY_SIZE(startup_lookup); i++)
+		if (startup_lookup[i] > ticks_min)
+			break;
+
+	return i;
+}
+
+static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq)
+{
+	struct iio_dev *indio_dev = iio_priv_to_dev(st);
+	unsigned f_per, prescal, startup;
+
+	f_per = clk_get_rate(st->per_clk);
+	prescal = (f_per / (2 * freq)) - 1;
+
+	startup = at91_adc_startup_time(st->soc_info.startup_time,
+					freq / 1000);
+
+	at91_adc_writel(st, AT91_SAMA5D2_MR,
+			AT91_SAMA5D2_MR_TRANSFER(2)
+			| AT91_SAMA5D2_MR_STARTUP(startup)
+			| AT91_SAMA5D2_MR_PRESCAL(prescal));
+
+	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n",
+		freq, startup, prescal);
+}
+
+static unsigned at91_adc_get_sample_freq(struct at91_adc_state *st)
+{
+	unsigned f_adc, f_per = clk_get_rate(st->per_clk);
+	unsigned mr, prescal;
+
+	mr = at91_adc_readl(st, AT91_SAMA5D2_MR);
+	prescal = (mr >> AT91_SAMA5D2_MR_PRESCAL_OFFSET)
+		  & AT91_SAMA5D2_MR_PRESCAL_MAX;
+	f_adc = f_per / (2 * (prescal + 1));
+
+	return f_adc;
+}
+
+static irqreturn_t at91_adc_interrupt(int irq, void *private)
+{
+	struct iio_dev *indio = private;
+	struct at91_adc_state *st = iio_priv(indio);
+	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
+	u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR);
+
+	if (status & imr) {
+		st->conversion_value = at91_adc_readl(st, st->chan->address);
+		st->conversion_done = true;
+		wake_up_interruptible(&st->wq_data_available);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int at91_adc_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct at91_adc_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&st->lock);
+
+		st->chan = chan;
+
+		at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
+		at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel));
+		at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
+
+		ret = wait_event_interruptible_timeout(st->wq_data_available,
+						       st->conversion_done,
+						       msecs_to_jiffies(1000));
+		if (ret == 0)
+			ret = -ETIMEDOUT;
+
+		if (ret > 0) {
+			*val = st->conversion_value;
+			ret = IIO_VAL_INT;
+			st->conversion_done = false;
+		}
+
+		at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel));
+		at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
+
+		mutex_unlock(&st->lock);
+		return ret;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = st->vref_uv / 1000;
+		*val2 = chan->scan_type.realbits;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = at91_adc_get_sample_freq(st);
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int at91_adc_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	struct at91_adc_state *st = iio_priv(indio_dev);
+
+	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
+		return -EINVAL;
+
+	if (val < st->soc_info.min_sample_rate ||
+	    val > st->soc_info.max_sample_rate)
+		return -EINVAL;
+
+	at91_adc_setup_samp_freq(st, val);
+
+	return 0;
+}
+
+static const struct iio_info at91_adc_info = {
+	.read_raw = &at91_adc_read_raw,
+	.write_raw = &at91_adc_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int at91_adc_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct at91_adc_state *st;
+	struct resource	*res;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+					  sizeof(struct at91_adc_state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &at91_adc_info;
+	indio_dev->channels = at91_adc_channels;
+	indio_dev->num_channels = ARRAY_SIZE(at91_adc_channels);
+
+	st = iio_priv(indio_dev);
+
+	ret = of_property_read_u32(pdev->dev.of_node,
+				   "atmel,min-sample-rate-hz",
+				   &st->soc_info.min_sample_rate);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"invalid or missing value for atmel,min-sample-rate-hz\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(pdev->dev.of_node,
+				   "atmel,max-sample-rate-hz",
+				   &st->soc_info.max_sample_rate);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"invalid or missing value for atmel,max-sample-rate-hz\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(pdev->dev.of_node, "atmel,startup-time-ms",
+				   &st->soc_info.startup_time);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"invalid or missing value for atmel,startup-time-ms\n");
+		return ret;
+	}
+
+	init_waitqueue_head(&st->wq_data_available);
+	mutex_init(&st->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	st->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(st->base))
+		return PTR_ERR(st->base);
+
+	st->irq = platform_get_irq(pdev, 0);
+	if (st->irq <= 0) {
+		if (!st->irq)
+			st->irq = -ENXIO;
+
+		return st->irq;
+	}
+
+	st->per_clk = devm_clk_get(&pdev->dev, "adc_clk");
+	if (IS_ERR(st->per_clk))
+		return PTR_ERR(st->per_clk);
+
+	st->reg = devm_regulator_get(&pdev->dev, "vddana");
+	if (IS_ERR(st->reg))
+		return PTR_ERR(st->reg);
+
+	st->vref = devm_regulator_get(&pdev->dev, "vref");
+	if (IS_ERR(st->vref))
+		return PTR_ERR(st->vref);
+
+	ret = devm_request_irq(&pdev->dev, st->irq, at91_adc_interrupt, 0,
+			       pdev->dev.driver->name, indio_dev);
+	if (ret)
+		return ret;
+
+	ret = regulator_enable(st->reg);
+	if (ret)
+		return ret;
+
+	ret = regulator_enable(st->vref);
+	if (ret)
+		goto reg_disable;
+
+	st->vref_uv = regulator_get_voltage(st->vref);
+	if (st->vref_uv <= 0) {
+		ret = -EINVAL;
+		goto vref_disable;
+	}
+
+	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
+	at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff);
+
+	at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate);
+
+	ret = clk_prepare_enable(st->per_clk);
+	if (ret)
+		goto vref_disable;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto per_clk_disable_unprepare;
+
+	dev_info(&pdev->dev, "version: %x\n",
+		 readl_relaxed(st->base + AT91_SAMA5D2_VERSION));
+
+	return 0;
+
+per_clk_disable_unprepare:
+	clk_disable_unprepare(st->per_clk);
+vref_disable:
+	regulator_disable(st->vref);
+reg_disable:
+	regulator_disable(st->reg);
+	return ret;
+}
+
+static int at91_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct at91_adc_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	clk_disable_unprepare(st->per_clk);
+
+	regulator_disable(st->vref);
+	regulator_disable(st->reg);
+
+	return 0;
+}
+
+static const struct of_device_id at91_adc_dt_match[] = {
+	{
+		.compatible = "atmel,sama5d2-adc",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, at91_adc_dt_match);
+
+static struct platform_driver at91_adc_driver = {
+	.probe = at91_adc_probe,
+	.remove = at91_adc_remove,
+	.driver = {
+		.name = "at91-sama5d2_adc",
+		.of_match_table = at91_adc_dt_match,
+	},
+};
+module_platform_driver(at91_adc_driver)
+
+MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
+MODULE_DESCRIPTION("Atmel AT91 SAMA5D2 ADC");
+MODULE_LICENSE("GPL v2");
-- 
2.5.0

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#1309438 — [PATCH v3 5/5] ARM: at91/defconfig: add sama5d2 adc support in sama5_defconfig

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
---
 arch/arm/configs/sama5_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/sama5_defconfig b/arch/arm/configs/sama5_defconfig
index c11bab7..afbda41 100644
--- a/arch/arm/configs/sama5_defconfig
+++ b/arch/arm/configs/sama5_defconfig
@@ -187,6 +187,7 @@ CONFIG_AT_XDMAC=y
 # CONFIG_IOMMU_SUPPORT is not set
 CONFIG_IIO=y
 CONFIG_AT91_ADC=y
+CONFIG_AT91_SAMA5D2_ADC=y
 CONFIG_PWM=y
 CONFIG_PWM_ATMEL=y
 CONFIG_PWM_ATMEL_TCB=y
-- 
2.5.0

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