From bf04c1a367e3d52b2e071cc7c7047c27dc1c3c5f Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Wed, 27 May 2015 14:47:51 +0200 Subject: [PATCH] iio: adc: vf610: implement configurable conversion modes Support configurable conversion mode through sysfs. So far, the mode used was low-power, which is enabled by default now. Beside that, the modes normal and high-speed are selectable as well. Use the new device tree property which specifies the maximum ADC conversion clock frequencies. Depending on the mode used, the available resulting conversion frequency are calculated dynamically. Acked-by: Fugang Duan Signed-off-by: Stefan Agner Signed-off-by: Jonathan Cameron --- Documentation/ABI/testing/sysfs-bus-iio-vf610 | 7 + .../devicetree/bindings/iio/adc/vf610-adc.txt | 9 ++ drivers/iio/adc/vf610_adc.c | 146 +++++++++++++----- 3 files changed, 120 insertions(+), 42 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-vf610 diff --git a/Documentation/ABI/testing/sysfs-bus-iio-vf610 b/Documentation/ABI/testing/sysfs-bus-iio-vf610 new file mode 100644 index 000000000000..ecbc1f4af921 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-vf610 @@ -0,0 +1,7 @@ +What: /sys/bus/iio/devices/iio:deviceX/conversion_mode +KernelVersion: 4.2 +Contact: linux-iio@vger.kernel.org +Description: + Specifies the hardware conversion mode used. The three + available modes are "normal", "high-speed" and "low-power", + where the last is the default mode. diff --git a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt index 1a4a43d5c9ea..3eb40e20c143 100644 --- a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt +++ b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt @@ -11,6 +11,13 @@ Required properties: - clock-names: Must contain "adc", matching entry in the clocks property. - vref-supply: The regulator supply ADC reference voltage. +Recommended properties: +- fsl,adck-max-frequency: Maximum frequencies according to datasheets operating + requirements. Three values are required, depending on conversion mode: + - Frequency in normal mode (ADLPC=0, ADHSC=0) + - Frequency in high-speed mode (ADLPC=0, ADHSC=1) + - Frequency in low-power mode (ADLPC=1, ADHSC=0) + Example: adc0: adc@4003b000 { compatible = "fsl,vf610-adc"; @@ -18,5 +25,7 @@ adc0: adc@4003b000 { interrupts = <0 53 0x04>; clocks = <&clks VF610_CLK_ADC0>; clock-names = "adc"; + fsl,adck-max-frequency = <30000000>, <40000000>, + <20000000>; vref-supply = <®_vcc_3v3_mcu>; }; diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c index 56292ae4538d..480f335a0f9f 100644 --- a/drivers/iio/adc/vf610_adc.c +++ b/drivers/iio/adc/vf610_adc.c @@ -118,15 +118,21 @@ enum average_sel { VF610_ADC_SAMPLE_32, }; +enum conversion_mode_sel { + VF610_ADC_CONV_NORMAL, + VF610_ADC_CONV_HIGH_SPEED, + VF610_ADC_CONV_LOW_POWER, +}; + struct vf610_adc_feature { enum clk_sel clk_sel; enum vol_ref vol_ref; + enum conversion_mode_sel conv_mode; int clk_div; int sample_rate; int res_mode; - bool lpm; bool calibration; bool ovwren; }; @@ -139,6 +145,8 @@ struct vf610_adc { u32 vref_uv; u32 value; struct regulator *vref; + + u32 max_adck_rate[3]; struct vf610_adc_feature adc_feature; u32 sample_freq_avail[5]; @@ -148,46 +156,22 @@ struct vf610_adc { static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 }; -#define VF610_ADC_CHAN(_idx, _chan_type) { \ - .type = (_chan_type), \ - .indexed = 1, \ - .channel = (_idx), \ - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ - BIT(IIO_CHAN_INFO_SAMP_FREQ), \ -} - -#define VF610_ADC_TEMPERATURE_CHAN(_idx, _chan_type) { \ - .type = (_chan_type), \ - .channel = (_idx), \ - .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ -} - -static const struct iio_chan_spec vf610_adc_iio_channels[] = { - VF610_ADC_CHAN(0, IIO_VOLTAGE), - VF610_ADC_CHAN(1, IIO_VOLTAGE), - VF610_ADC_CHAN(2, IIO_VOLTAGE), - VF610_ADC_CHAN(3, IIO_VOLTAGE), - VF610_ADC_CHAN(4, IIO_VOLTAGE), - VF610_ADC_CHAN(5, IIO_VOLTAGE), - VF610_ADC_CHAN(6, IIO_VOLTAGE), - VF610_ADC_CHAN(7, IIO_VOLTAGE), - VF610_ADC_CHAN(8, IIO_VOLTAGE), - VF610_ADC_CHAN(9, IIO_VOLTAGE), - VF610_ADC_CHAN(10, IIO_VOLTAGE), - VF610_ADC_CHAN(11, IIO_VOLTAGE), - VF610_ADC_CHAN(12, IIO_VOLTAGE), - VF610_ADC_CHAN(13, IIO_VOLTAGE), - VF610_ADC_CHAN(14, IIO_VOLTAGE), - VF610_ADC_CHAN(15, IIO_VOLTAGE), - VF610_ADC_TEMPERATURE_CHAN(26, IIO_TEMP), - /* sentinel */ -}; - static inline void vf610_adc_calculate_rates(struct vf610_adc *info) { + struct vf610_adc_feature *adc_feature = &info->adc_feature; unsigned long adck_rate, ipg_rate = clk_get_rate(info->clk); - int i; + int divisor, i; + + adck_rate = info->max_adck_rate[adc_feature->conv_mode]; + + if (adck_rate) { + /* calculate clk divider which is within specification */ + divisor = ipg_rate / adck_rate; + adc_feature->clk_div = 1 << fls(divisor + 1); + } else { + /* fall-back value using a safe divisor */ + adc_feature->clk_div = 8; + } /* * Calculate ADC sample frequencies @@ -219,10 +203,8 @@ static inline void vf610_adc_cfg_init(struct vf610_adc *info) adc_feature->res_mode = 12; adc_feature->sample_rate = 1; - adc_feature->lpm = true; - /* Use a save ADCK which is below 20MHz on all devices */ - adc_feature->clk_div = 8; + adc_feature->conv_mode = VF610_ADC_CONV_LOW_POWER; vf610_adc_calculate_rates(info); } @@ -304,10 +286,12 @@ static void vf610_adc_cfg_set(struct vf610_adc *info) cfg_data = readl(info->regs + VF610_REG_ADC_CFG); cfg_data &= ~VF610_ADC_ADLPC_EN; - if (adc_feature->lpm) + if (adc_feature->conv_mode == VF610_ADC_CONV_LOW_POWER) cfg_data |= VF610_ADC_ADLPC_EN; cfg_data &= ~VF610_ADC_ADHSC_EN; + if (adc_feature->conv_mode == VF610_ADC_CONV_HIGH_SPEED) + cfg_data |= VF610_ADC_ADHSC_EN; writel(cfg_data, info->regs + VF610_REG_ADC_CFG); } @@ -409,6 +393,81 @@ static void vf610_adc_hw_init(struct vf610_adc *info) vf610_adc_cfg_set(info); } +static int vf610_set_conversion_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + unsigned int mode) +{ + struct vf610_adc *info = iio_priv(indio_dev); + + mutex_lock(&indio_dev->mlock); + info->adc_feature.conv_mode = mode; + vf610_adc_calculate_rates(info); + vf610_adc_hw_init(info); + mutex_unlock(&indio_dev->mlock); + + return 0; +} + +static int vf610_get_conversion_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct vf610_adc *info = iio_priv(indio_dev); + + return info->adc_feature.conv_mode; +} + +static const char * const vf610_conv_modes[] = { "normal", "high-speed", + "low-power" }; + +static const struct iio_enum vf610_conversion_mode = { + .items = vf610_conv_modes, + .num_items = ARRAY_SIZE(vf610_conv_modes), + .get = vf610_get_conversion_mode, + .set = vf610_set_conversion_mode, +}; + +static const struct iio_chan_spec_ext_info vf610_ext_info[] = { + IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR, &vf610_conversion_mode), + {}, +}; + +#define VF610_ADC_CHAN(_idx, _chan_type) { \ + .type = (_chan_type), \ + .indexed = 1, \ + .channel = (_idx), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .ext_info = vf610_ext_info, \ +} + +#define VF610_ADC_TEMPERATURE_CHAN(_idx, _chan_type) { \ + .type = (_chan_type), \ + .channel = (_idx), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ +} + +static const struct iio_chan_spec vf610_adc_iio_channels[] = { + VF610_ADC_CHAN(0, IIO_VOLTAGE), + VF610_ADC_CHAN(1, IIO_VOLTAGE), + VF610_ADC_CHAN(2, IIO_VOLTAGE), + VF610_ADC_CHAN(3, IIO_VOLTAGE), + VF610_ADC_CHAN(4, IIO_VOLTAGE), + VF610_ADC_CHAN(5, IIO_VOLTAGE), + VF610_ADC_CHAN(6, IIO_VOLTAGE), + VF610_ADC_CHAN(7, IIO_VOLTAGE), + VF610_ADC_CHAN(8, IIO_VOLTAGE), + VF610_ADC_CHAN(9, IIO_VOLTAGE), + VF610_ADC_CHAN(10, IIO_VOLTAGE), + VF610_ADC_CHAN(11, IIO_VOLTAGE), + VF610_ADC_CHAN(12, IIO_VOLTAGE), + VF610_ADC_CHAN(13, IIO_VOLTAGE), + VF610_ADC_CHAN(14, IIO_VOLTAGE), + VF610_ADC_CHAN(15, IIO_VOLTAGE), + VF610_ADC_TEMPERATURE_CHAN(26, IIO_TEMP), + /* sentinel */ +}; + static int vf610_adc_read_data(struct vf610_adc *info) { int result; @@ -651,6 +710,9 @@ static int vf610_adc_probe(struct platform_device *pdev) info->vref_uv = regulator_get_voltage(info->vref); + of_property_read_u32_array(pdev->dev.of_node, "fsl,adck-max-frequency", + info->max_adck_rate, 3); + platform_set_drvdata(pdev, indio_dev); init_completion(&info->completion); -- 2.20.1