iio: adc: add support for Berlin
authorAntoine Tenart <antoine.tenart@free-electrons.com>
Mon, 18 May 2015 09:19:18 +0000 (11:19 +0200)
committerJonathan Cameron <jic23@kernel.org>
Sat, 23 May 2015 09:47:40 +0000 (10:47 +0100)
This patch adds the support of the Berlin ADC, available on Berlin SoCs.
This ADC has 8 channels available, with one connected to a temperature
sensor.

The particularity here, is that the temperature sensor connected to the
ADC has its own registers, and both the ADC and the temperature sensor
must be configured when using it.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/adc/Kconfig
drivers/iio/adc/Makefile
drivers/iio/adc/berlin2-adc.c [new file with mode: 0644]

index e36a73e7c3a857775103bb1f9212d56ac2cba09c..cee50de76fb152e725c96388470a967fafac34ed 100644 (file)
@@ -135,6 +135,13 @@ config AXP288_ADC
          device. Depending on platform configuration, this general purpose ADC can
          be used for sampling sensors such as thermal resistors.
 
+config BERLIN2_ADC
+       tristate "Marvell Berlin2 ADC driver"
+       depends on ARCH_BERLIN
+       help
+         Marvell Berlin2 ADC driver. This ADC has 8 channels, with one used for
+         temperature measurement.
+
 config DA9150_GPADC
        tristate "Dialog DA9150 GPADC driver support"
        depends on MFD_DA9150
index 3930e63e84bccb809b3b98ad9c9cbfae7d2889e3..a0962103e8666cba5e4c844a0e36101f3677dc0e 100644 (file)
@@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
+obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
diff --git a/drivers/iio/adc/berlin2-adc.c b/drivers/iio/adc/berlin2-adc.c
new file mode 100644 (file)
index 0000000..aecc9ad
--- /dev/null
@@ -0,0 +1,378 @@
+/*
+ * Marvell Berlin2 ADC driver
+ *
+ * Copyright (C) 2015 Marvell Technology Group Ltd.
+ *
+ * Antoine Tenart <antoine.tenart@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/iio/machine.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#define BERLIN2_SM_CTRL                                0x14
+#define  BERLIN2_SM_CTRL_SM_SOC_INT            BIT(1)
+#define  BERLIN2_SM_CTRL_SOC_SM_INT            BIT(2)
+#define  BERLIN2_SM_CTRL_ADC_SEL(x)            (BIT(x) << 5)   /* 0-15 */
+#define  BERLIN2_SM_CTRL_ADC_SEL_MASK          (0xf << 5)
+#define  BERLIN2_SM_CTRL_ADC_POWER             BIT(9)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2       (0x0 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3       (0x1 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4       (0x2 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8       (0x3 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_MASK       (0x3 << 10)
+#define  BERLIN2_SM_CTRL_ADC_START             BIT(12)
+#define  BERLIN2_SM_CTRL_ADC_RESET             BIT(13)
+#define  BERLIN2_SM_CTRL_ADC_BANDGAP_RDY       BIT(14)
+#define  BERLIN2_SM_CTRL_ADC_CONT_SINGLE       (0x0 << 15)
+#define  BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS   (0x1 << 15)
+#define  BERLIN2_SM_CTRL_ADC_BUFFER_EN         BIT(16)
+#define  BERLIN2_SM_CTRL_ADC_VREF_EXT          (0x0 << 17)
+#define  BERLIN2_SM_CTRL_ADC_VREF_INT          (0x1 << 17)
+#define  BERLIN2_SM_CTRL_ADC_ROTATE            BIT(19)
+#define  BERLIN2_SM_CTRL_TSEN_EN               BIT(20)
+#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_125      (0x0 << 21)     /* 1.25 MHz */
+#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_250      (0x1 << 21)     /* 2.5 MHz */
+#define  BERLIN2_SM_CTRL_TSEN_MODE_0_125       (0x0 << 22)     /* 0-125 C */
+#define  BERLIN2_SM_CTRL_TSEN_MODE_10_50       (0x1 << 22)     /* 10-50 C */
+#define  BERLIN2_SM_CTRL_TSEN_RESET            BIT(29)
+#define BERLIN2_SM_ADC_DATA                    0x20
+#define  BERLIN2_SM_ADC_MASK                   0x3ff
+#define BERLIN2_SM_ADC_STATUS                  0x1c
+#define  BERLIN2_SM_ADC_STATUS_DATA_RDY(x)     BIT(x)          /* 0-15 */
+#define  BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK   0xf
+#define  BERLIN2_SM_ADC_STATUS_INT_EN(x)       (BIT(x) << 16)  /* 0-15 */
+#define  BERLIN2_SM_ADC_STATUS_INT_EN_MASK     (0xf << 16)
+#define BERLIN2_SM_TSEN_STATUS                 0x24
+#define  BERLIN2_SM_TSEN_STATUS_DATA_RDY       BIT(0)
+#define  BERLIN2_SM_TSEN_STATUS_INT_EN         BIT(1)
+#define BERLIN2_SM_TSEN_DATA                   0x28
+#define  BERLIN2_SM_TSEN_MASK                  0xfff
+#define BERLIN2_SM_TSEN_CTRL                   0x74
+#define  BERLIN2_SM_TSEN_CTRL_START            BIT(8)
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_4       (0x0 << 21)     /* 4 us */
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_12      (0x1 << 21)     /* 12 us */
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_MASK    (0x1 << 21)
+#define  BERLIN2_SM_TSEN_CTRL_TRIM(x)          ((x) << 22)
+#define  BERLIN2_SM_TSEN_CTRL_TRIM_MASK                (0xf << 22)
+
+struct berlin2_adc_priv {
+       struct regmap           *regmap;
+       struct mutex            lock;
+       wait_queue_head_t       wq;
+       bool                    data_available;
+       int                     data;
+};
+
+#define BERLIN2_ADC_CHANNEL(n, t)                                      \
+               {                                                       \
+                       .channel        = n,                            \
+                       .datasheet_name = "channel"#n,                  \
+                       .type           = t,                            \
+                       .indexed        = 1,                            \
+                       .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
+               }
+
+static struct iio_chan_spec berlin2_adc_channels[] = {
+       BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE),    /* external input */
+       BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE),    /* external input */
+       BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE),    /* external input */
+       BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE),    /* external input */
+       BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE),    /* reserved */
+       BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE),    /* reserved */
+       {                                       /* temperature sensor */
+               .channel                = 6,
+               .datasheet_name         = "channel6",
+               .type                   = IIO_TEMP,
+               .indexed                = 0,
+               .info_mask_separate     = BIT(IIO_CHAN_INFO_PROCESSED),
+       },
+       BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE),    /* reserved */
+       IIO_CHAN_SOFT_TIMESTAMP(8),             /* timestamp */
+};
+#define BERLIN2_N_CHANNELS     ARRAY_SIZE(berlin2_adc_channels)
+
+static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
+{
+       struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+       int data, ret;
+
+       mutex_lock(&priv->lock);
+
+       /* Configure the ADC */
+       regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+                       BERLIN2_SM_CTRL_ADC_RESET | BERLIN2_SM_CTRL_ADC_SEL_MASK
+                       | BERLIN2_SM_CTRL_ADC_START,
+                       BERLIN2_SM_CTRL_ADC_SEL(channel) | BERLIN2_SM_CTRL_ADC_START);
+
+       ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
+                       msecs_to_jiffies(1000));
+
+       /* Disable the interrupts */
+       regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
+                       BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
+
+       if (ret == 0)
+               ret = -ETIMEDOUT;
+       if (ret < 0) {
+               mutex_unlock(&priv->lock);
+               return ret;
+       }
+
+       regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+                       BERLIN2_SM_CTRL_ADC_START, 0);
+
+       data = priv->data;
+       priv->data_available = false;
+
+       mutex_unlock(&priv->lock);
+
+       return data;
+}
+
+static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
+{
+       struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+       int data, ret;
+
+       mutex_lock(&priv->lock);
+
+       /* Configure the ADC */
+       regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+                       BERLIN2_SM_CTRL_TSEN_RESET | BERLIN2_SM_CTRL_ADC_ROTATE,
+                       BERLIN2_SM_CTRL_ADC_ROTATE);
+
+       /* Configure the temperature sensor */
+       regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
+                       BERLIN2_SM_TSEN_CTRL_TRIM_MASK | BERLIN2_SM_TSEN_CTRL_SETTLING_MASK
+                       | BERLIN2_SM_TSEN_CTRL_START,
+                       BERLIN2_SM_TSEN_CTRL_TRIM(3) | BERLIN2_SM_TSEN_CTRL_SETTLING_12
+                       | BERLIN2_SM_TSEN_CTRL_START);
+
+       ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
+                       msecs_to_jiffies(1000));
+
+       /* Disable interrupts */
+       regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
+                       BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
+
+       if (ret == 0)
+               ret = -ETIMEDOUT;
+       if (ret < 0) {
+               mutex_unlock(&priv->lock);
+               return ret;
+       }
+
+       regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
+                       BERLIN2_SM_TSEN_CTRL_START, 0);
+
+       data = priv->data;
+       priv->data_available = false;
+
+       mutex_unlock(&priv->lock);
+
+       return data;
+}
+
+static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
+               struct iio_chan_spec const *chan, int *val, int *val2,
+               long mask)
+{
+       struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+       int temp;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               if (chan->type != IIO_VOLTAGE)
+                       return -EINVAL;
+
+               /* Enable the interrupts */
+               regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
+                               BERLIN2_SM_ADC_STATUS_INT_EN(chan->channel));
+
+               *val = berlin2_adc_read(indio_dev, chan->channel);
+               if (*val < 0)
+                       return *val;
+
+               return IIO_VAL_INT;
+       case IIO_CHAN_INFO_PROCESSED:
+               if (chan->type != IIO_TEMP)
+                       return -EINVAL;
+
+               /* Enable interrupts */
+               regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
+                               BERLIN2_SM_TSEN_STATUS_INT_EN);
+
+               temp = berlin2_adc_tsen_read(indio_dev);
+               if (temp < 0)
+                       return temp;
+
+               if (temp > 2047)
+                       temp = -(4096 - temp);
+
+               /* Convert to milli Celsius */
+               *val = ((temp * 100000) / 264 - 270000);
+               return IIO_VAL_INT;
+       default:
+               break;
+       }
+
+       return -EINVAL;
+}
+
+static irqreturn_t berlin2_adc_irq(int irq, void *private)
+{
+       struct berlin2_adc_priv *priv = iio_priv(private);
+       unsigned val;
+
+       regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
+       if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
+               regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
+               priv->data &= BERLIN2_SM_ADC_MASK;
+
+               val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
+               regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
+
+               priv->data_available = true;
+               wake_up_interruptible(&priv->wq);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
+{
+       struct berlin2_adc_priv *priv = iio_priv(private);
+       unsigned val;
+
+       regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
+       if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
+               regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
+               priv->data &= BERLIN2_SM_TSEN_MASK;
+
+               val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
+               regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
+
+               priv->data_available = true;
+               wake_up_interruptible(&priv->wq);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static const struct iio_info berlin2_adc_info = {
+       .driver_module  = THIS_MODULE,
+       .read_raw       = berlin2_adc_read_raw,
+};
+
+static int berlin2_adc_probe(struct platform_device *pdev)
+{
+       struct iio_dev *indio_dev;
+       struct berlin2_adc_priv *priv;
+       struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
+       int irq, tsen_irq;
+       int ret;
+
+       indio_dev = devm_iio_device_alloc(&pdev->dev,
+                                         sizeof(struct berlin2_adc_priv));
+       if (!indio_dev)
+               return -ENOMEM;
+
+       priv = iio_priv(indio_dev);
+       platform_set_drvdata(pdev, indio_dev);
+
+       priv->regmap = syscon_node_to_regmap(parent_np);
+       of_node_put(parent_np);
+       if (IS_ERR(priv->regmap))
+               return PTR_ERR(priv->regmap);
+
+       irq = platform_get_irq_byname(pdev, "adc");
+       if (irq < 0)
+               return -ENODEV;
+
+       tsen_irq = platform_get_irq_byname(pdev, "tsen");
+       if (tsen_irq < 0)
+               return -ENODEV;
+
+       ret = devm_request_irq(&pdev->dev, irq, berlin2_adc_irq, 0,
+                       pdev->dev.driver->name, indio_dev);
+       if (ret)
+               return ret;
+
+       ret = devm_request_irq(&pdev->dev, tsen_irq, berlin2_adc_tsen_irq,
+                       0, pdev->dev.driver->name, indio_dev);
+       if (ret)
+               return ret;
+
+       init_waitqueue_head(&priv->wq);
+       mutex_init(&priv->lock);
+
+       indio_dev->dev.parent = &pdev->dev;
+       indio_dev->name = dev_name(&pdev->dev);
+       indio_dev->modes = INDIO_DIRECT_MODE;
+       indio_dev->info = &berlin2_adc_info;
+
+       indio_dev->num_channels = BERLIN2_N_CHANNELS;
+       indio_dev->channels = berlin2_adc_channels;
+
+       /* Power up the ADC */
+       regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+                       BERLIN2_SM_CTRL_ADC_POWER, BERLIN2_SM_CTRL_ADC_POWER);
+
+       ret = iio_device_register(indio_dev);
+       if (ret) {
+               /* Power down the ADC */
+               regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+                               BERLIN2_SM_CTRL_ADC_POWER, 0);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int berlin2_adc_remove(struct platform_device *pdev)
+{
+       struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+       struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+
+       iio_device_unregister(indio_dev);
+
+       /* Power down the ADC */
+       regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+                       BERLIN2_SM_CTRL_ADC_POWER, 0);
+
+       return 0;
+}
+
+static const struct of_device_id berlin2_adc_match[] = {
+       { .compatible = "marvell,berlin2-adc", },
+       { },
+};
+MODULE_DEVICE_TABLE(of, berlin2_adc_match);
+
+static struct platform_driver berlin2_adc_driver = {
+       .driver = {
+               .name           = "berlin2-adc",
+               .of_match_table = berlin2_adc_match,
+       },
+       .probe  = berlin2_adc_probe,
+       .remove = berlin2_adc_remove,
+};
+module_platform_driver(berlin2_adc_driver);
+
+MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
+MODULE_LICENSE("GPL v2");