#include <linux/err.h>
#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
#include <linux/iio/sysfs.h>
-#include <linux/iio/driver.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
/* This will be the driver name the kernel reports */
#define DRIVER_NAME "vf610-adc"
#define VF610_ADC_CLK_DIV8 0x60
#define VF610_ADC_CLK_MASK 0x60
#define VF610_ADC_ADLSMP_LONG 0x10
+#define VF610_ADC_ADSTS_SHORT 0x100
+#define VF610_ADC_ADSTS_NORMAL 0x200
+#define VF610_ADC_ADSTS_LONG 0x300
#define VF610_ADC_ADSTS_MASK 0x300
#define VF610_ADC_ADLPC_EN 0x80
#define VF610_ADC_ADHSC_EN 0x400
#define VF610_ADC_CALF 0x2
#define VF610_ADC_TIMEOUT msecs_to_jiffies(100)
+#define DEFAULT_SAMPLE_TIME 1000
+
+/* V at 25°C of 696 mV */
+#define VF610_VTEMP25_3V0 950
+/* V at 25°C of 699 mV */
+#define VF610_VTEMP25_3V3 867
+/* Typical sensor slope coefficient at all temperatures */
+#define VF610_TEMP_SLOPE_COEFF 1840
+
enum clk_sel {
VF610_ADCIOC_BUSCLK_SET,
VF610_ADCIOC_ALTCLK_SET,
VF610_ADC_SAMPLE_32,
};
+enum conversion_mode_sel {
+ VF610_ADC_CONV_NORMAL,
+ VF610_ADC_CONV_HIGH_SPEED,
+ VF610_ADC_CONV_LOW_POWER,
+};
+
+enum lst_adder_sel {
+ VF610_ADCK_CYCLES_3,
+ VF610_ADCK_CYCLES_5,
+ VF610_ADCK_CYCLES_7,
+ VF610_ADCK_CYCLES_9,
+ VF610_ADCK_CYCLES_13,
+ VF610_ADCK_CYCLES_17,
+ VF610_ADCK_CYCLES_21,
+ VF610_ADCK_CYCLES_25,
+};
+
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;
+ u32 lst_adder_index;
+ u32 default_sample_time;
- bool lpm;
bool calibration;
bool ovwren;
};
u32 vref_uv;
u32 value;
struct regulator *vref;
+
+ u32 max_adck_rate[3];
struct vf610_adc_feature adc_feature;
u32 sample_freq_avail[5];
struct completion completion;
+ u16 buffer[8];
};
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 const u32 vf610_lst_adder[] = { 3, 5, 7, 9, 13, 17, 21, 25 };
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;
+ u32 adck_period, lst_addr_min;
+ 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;
+ }
+
+ adck_rate = ipg_rate / adc_feature->clk_div;
+
+ /*
+ * Determine the long sample time adder value to be used based
+ * on the default minimum sample time provided.
+ */
+ adck_period = NSEC_PER_SEC / adck_rate;
+ lst_addr_min = adc_feature->default_sample_time / adck_period;
+ for (i = 0; i < ARRAY_SIZE(vf610_lst_adder); i++) {
+ if (vf610_lst_adder[i] > lst_addr_min) {
+ adc_feature->lst_adder_index = i;
+ break;
+ }
+ }
/*
* Calculate ADC sample frequencies
* SFCAdder: fixed to 6 ADCK cycles
* AverageNum: 1, 4, 8, 16, 32 samples for hardware average.
* BCT (Base Conversion Time): fixed to 25 ADCK cycles for 12 bit mode
- * LSTAdder(Long Sample Time): fixed to 3 ADCK cycles
+ * LSTAdder(Long Sample Time): 3, 5, 7, 9, 13, 17, 21, 25 ADCK cycles
*/
- adck_rate = ipg_rate / info->adc_feature.clk_div;
for (i = 0; i < ARRAY_SIZE(vf610_hw_avgs); i++)
info->sample_freq_avail[i] =
- adck_rate / (6 + vf610_hw_avgs[i] * (25 + 3));
+ adck_rate / (6 + vf610_hw_avgs[i] *
+ (25 + vf610_lst_adder[adc_feature->lst_adder_index]));
}
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);
}
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);
}
break;
}
- /* Use the short sample mode */
- cfg_data &= ~(VF610_ADC_ADLSMP_LONG | VF610_ADC_ADSTS_MASK);
+ /*
+ * Set ADLSMP and ADSTS based on the Long Sample Time Adder value
+ * determined.
+ */
+ switch (adc_feature->lst_adder_index) {
+ case VF610_ADCK_CYCLES_3:
+ break;
+ case VF610_ADCK_CYCLES_5:
+ cfg_data |= VF610_ADC_ADSTS_SHORT;
+ break;
+ case VF610_ADCK_CYCLES_7:
+ cfg_data |= VF610_ADC_ADSTS_NORMAL;
+ break;
+ case VF610_ADCK_CYCLES_9:
+ cfg_data |= VF610_ADC_ADSTS_LONG;
+ break;
+ case VF610_ADCK_CYCLES_13:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ break;
+ case VF610_ADCK_CYCLES_17:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ cfg_data |= VF610_ADC_ADSTS_SHORT;
+ break;
+ case VF610_ADCK_CYCLES_21:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ cfg_data |= VF610_ADC_ADSTS_NORMAL;
+ break;
+ case VF610_ADCK_CYCLES_25:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ cfg_data |= VF610_ADC_ADSTS_NORMAL;
+ break;
+ default:
+ dev_err(info->dev, "error in sample time select\n");
+ }
/* update hardware average selection */
cfg_data &= ~VF610_ADC_AVGS_MASK;
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, \
+ .scan_index = (_idx), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ }, \
+}
+
+#define VF610_ADC_TEMPERATURE_CHAN(_idx, _chan_type) { \
+ .type = (_chan_type), \
+ .channel = (_idx), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
+ .scan_index = (_idx), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ }, \
+}
+
+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),
+ IIO_CHAN_SOFT_TIMESTAMP(32),
+ /* sentinel */
+};
+
static int vf610_adc_read_data(struct vf610_adc *info)
{
int result;
static irqreturn_t vf610_adc_isr(int irq, void *dev_id)
{
- struct vf610_adc *info = (struct vf610_adc *)dev_id;
+ struct iio_dev *indio_dev = (struct iio_dev *)dev_id;
+ struct vf610_adc *info = iio_priv(indio_dev);
int coco;
coco = readl(info->regs + VF610_REG_ADC_HS);
if (coco & VF610_ADC_HS_COCO0) {
info->value = vf610_adc_read_data(info);
- complete(&info->completion);
+ if (iio_buffer_enabled(indio_dev)) {
+ info->buffer[0] = info->value;
+ iio_push_to_buffers_with_timestamp(indio_dev,
+ info->buffer, iio_get_time_ns());
+ iio_trigger_notify_done(indio_dev->trig);
+ } else
+ complete(&info->completion);
}
return IRQ_HANDLED;
case IIO_CHAN_INFO_RAW:
case IIO_CHAN_INFO_PROCESSED:
mutex_lock(&indio_dev->mlock);
- reinit_completion(&info->completion);
+ if (iio_buffer_enabled(indio_dev)) {
+ mutex_unlock(&indio_dev->mlock);
+ return -EBUSY;
+ }
+ reinit_completion(&info->completion);
hc_cfg = VF610_ADC_ADCHC(chan->channel);
hc_cfg |= VF610_ADC_AIEN;
writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
break;
case IIO_TEMP:
/*
- * Calculate in degree Celsius times 1000
- * Using sensor slope of 1.84 mV/°C and
- * V at 25°C of 696 mV
- */
- *val = 25000 - ((int)info->value - 864) * 1000000 / 1840;
+ * Calculate in degree Celsius times 1000
+ * Using the typical sensor slope of 1.84 mV/°C
+ * and VREFH_ADC at 3.3V, V at 25°C of 699 mV
+ */
+ *val = 25000 - ((int)info->value - VF610_VTEMP25_3V3) *
+ 1000000 / VF610_TEMP_SLOPE_COEFF;
+
break;
default:
mutex_unlock(&indio_dev->mlock);
return -EINVAL;
}
+static int vf610_adc_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct vf610_adc *info = iio_priv(indio_dev);
+ unsigned int channel;
+ int ret;
+ int val;
+
+ ret = iio_triggered_buffer_postenable(indio_dev);
+ if (ret)
+ return ret;
+
+ val = readl(info->regs + VF610_REG_ADC_GC);
+ val |= VF610_ADC_ADCON;
+ writel(val, info->regs + VF610_REG_ADC_GC);
+
+ channel = find_first_bit(indio_dev->active_scan_mask,
+ indio_dev->masklength);
+
+ val = VF610_ADC_ADCHC(channel);
+ val |= VF610_ADC_AIEN;
+
+ writel(val, info->regs + VF610_REG_ADC_HC0);
+
+ return 0;
+}
+
+static int vf610_adc_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct vf610_adc *info = iio_priv(indio_dev);
+ unsigned int hc_cfg = 0;
+ int val;
+
+ val = readl(info->regs + VF610_REG_ADC_GC);
+ val &= ~VF610_ADC_ADCON;
+ writel(val, info->regs + VF610_REG_ADC_GC);
+
+ hc_cfg |= VF610_ADC_CONV_DISABLE;
+ hc_cfg &= ~VF610_ADC_AIEN;
+
+ writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
+
+ return iio_triggered_buffer_predisable(indio_dev);
+}
+
+static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
+ .postenable = &vf610_adc_buffer_postenable,
+ .predisable = &vf610_adc_buffer_predisable,
+ .validate_scan_mask = &iio_validate_scan_mask_onehot,
+};
+
static int vf610_adc_reg_access(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval,
unsigned *readval)
struct vf610_adc *info = iio_priv(indio_dev);
if ((readval == NULL) ||
- (!(reg % 4) || (reg > VF610_REG_ADC_PCTL)))
+ ((reg % 4) || (reg > VF610_REG_ADC_PCTL)))
return -EINVAL;
*readval = readl(info->regs + reg);
ret = devm_request_irq(info->dev, irq,
vf610_adc_isr, 0,
- dev_name(&pdev->dev), info);
+ dev_name(&pdev->dev), indio_dev);
if (ret < 0) {
dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq);
return ret;
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);
+
+ ret = of_property_read_u32(pdev->dev.of_node, "min-sample-time",
+ &info->adc_feature.default_sample_time);
+ if (ret)
+ info->adc_feature.default_sample_time = DEFAULT_SAMPLE_TIME;
+
platform_set_drvdata(pdev, indio_dev);
init_completion(&info->completion);
vf610_adc_cfg_init(info);
vf610_adc_hw_init(info);
+ ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+ NULL, &iio_triggered_buffer_setup_ops);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't initialise the buffer\n");
+ goto error_iio_device_register;
+ }
+
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&pdev->dev, "Couldn't register the device.\n");
- goto error_iio_device_register;
+ goto error_adc_buffer_init;
}
return 0;
-
+error_adc_buffer_init:
+ iio_triggered_buffer_cleanup(indio_dev);
error_iio_device_register:
clk_disable_unprepare(info->clk);
error_adc_clk_enable:
struct vf610_adc *info = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
regulator_disable(info->vref);
clk_disable_unprepare(info->clk);
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