On Sat, Mar 25, 2017 at 06:26:05PM +0000, Jonathan Cameron wrote: > On 24/03/17 14:00, Benjamin Gaignard wrote: > > One of the features of STM32 trigger hardware block is a quadrature > > encoder that can counts up/down depending of the levels and edges > > of the selected external pins. > > > > This patch allow to read/write the counter, get it direction, > > set/get quadrature modes and get scale factor. > > > > When counting up preset value is the limit of the counter. > > When counting down the counter start from preset value down to 0. > > This preset value could be set/get by using > > /sys/bus/iio/devices/iio:deviceX/in_count0_preset attribute. > > > > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxx> > A few little nitpicks. > > Otherwise I like this. Would love William to give another review > though if he has time. > > I've tacked Michael Welling on the cc list as well as he has offered > to help the beaglebone lot upstream some drivers, including the > eqep quadrature encoder drivers - so he can poke the right people > to get some review of the ABI from their point of view as well. > BTW here is the out of tree module that will be converted to IIO eventually. https://github.com/Teknoman117/beaglebot/tree/master/encoders There are probably more requirements to encapsulate all of the features of the eQEP. > Thanks > > Jonathan > > --- > > .../ABI/testing/sysfs-bus-iio-timer-stm32 | 32 +++ > > drivers/iio/trigger/stm32-timer-trigger.c | 244 ++++++++++++++++++++- > > include/linux/mfd/stm32-timers.h | 2 + > > 3 files changed, 272 insertions(+), 6 deletions(-) > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 > > index 6534a60..fbdee4f 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 > > +++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 > > @@ -27,3 +27,35 @@ Description: > > Reading returns the current sampling frequency. > > Writing an value different of 0 set and start sampling. > > Writing 0 stop sampling. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_count0_preset > > +KernelVersion: 4.12 > > +Contact: benjamin.gaignard@xxxxxx > > +Description: > > + Reading returns the current preset value. > > + Writing set the preset value. > > + When counting up the counter start from 0 and fire an event when reach preset value. > > + When counting down the counter start from preset value and fire event when reach 0. > We'll want to generalize that description at some point as it's most often used as a place to reset > too on an event (homing switch or similar) > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available > > +KernelVersion: 4.12 > > +Contact: benjamin.gaignard@xxxxxx > > +Description: > > + Reading returns the list possible quadrature modes. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_count0_quadrature_mode > > +KernelVersion: 4.12 > > +Contact: benjamin.gaignard@xxxxxx > > +Description: > > + Configure the device counter quadrature modes: > > + channel_A: > > + Encoder A input severs as the count input and B as > > + the UP/DOWN direction control input. > > + > > + channel_B: > > + Encoder B input severs as the count input and A as > > + the UP/DOWN direction control input. > > + > > + quadrature: > > + Encoder A and B inputs are mixed to get direction > > + and count with a scale of 0.25. > Whilst the quadrature mode is always with that scale on this device, we should > as discussed be explicitly providing access to the scale so that we can > cope with different scales on different devices. As such the docs here > shouldn't mention it. > > I'm keen to get these docs straight into sysfs-bus-iio or perhaps > sysfs-bus-iio-encoder-counter asap so good to write them with that at the > front of your mind. > > > diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c > > index 994b96d..48d2bf9 100644 > > --- a/drivers/iio/trigger/stm32-timer-trigger.c > > +++ b/drivers/iio/trigger/stm32-timer-trigger.c > > @@ -15,6 +15,7 @@ > > #include <linux/platform_device.h> > > > > #define MAX_TRIGGERS 6 > > +#define MAX_VALIDS 5 > > > > /* List the triggers created by each timer */ > > static const void *triggers_table[][MAX_TRIGGERS] = { > > @@ -32,12 +33,29 @@ > > { TIM12_TRGO, TIM12_CH1, TIM12_CH2,}, > > }; > > > > +/* List the triggers accepted by each timer */ > > +static const void *valids_table[][MAX_VALIDS] = { > > + { TIM5_TRGO, TIM2_TRGO, TIM3_TRGO, TIM4_TRGO,}, > > + { TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,}, > > + { TIM1_TRGO, TIM2_TRGO, TIM5_TRGO, TIM4_TRGO,}, > > + { TIM1_TRGO, TIM2_TRGO, TIM3_TRGO, TIM8_TRGO,}, > > + { TIM2_TRGO, TIM3_TRGO, TIM4_TRGO, TIM8_TRGO,}, > > + { }, /* timer 6 */ > > + { }, /* timer 7 */ > > + { TIM1_TRGO, TIM2_TRGO, TIM4_TRGO, TIM5_TRGO,}, > > + { TIM2_TRGO, TIM3_TRGO,}, > > + { }, /* timer 10 */ > > + { }, /* timer 11 */ > > + { TIM4_TRGO, TIM5_TRGO,}, > > +}; > > + > > struct stm32_timer_trigger { > > struct device *dev; > > struct regmap *regmap; > > struct clk *clk; > > u32 max_arr; > > const void *triggers; > > + const void *valids; > > }; > > > > static int stm32_timer_start(struct stm32_timer_trigger *priv, > > @@ -180,8 +198,7 @@ static ssize_t stm32_tt_show_master_mode(struct device *dev, > > struct device_attribute *attr, > > char *buf) > > { > > - struct iio_dev *indio_dev = dev_to_iio_dev(dev); > > - struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + struct stm32_timer_trigger *priv = dev_get_drvdata(dev); > > u32 cr2; > > > > regmap_read(priv->regmap, TIM_CR2, &cr2); > > @@ -194,8 +211,7 @@ static ssize_t stm32_tt_store_master_mode(struct device *dev, > > struct device_attribute *attr, > > const char *buf, size_t len) > > { > > - struct iio_dev *indio_dev = dev_to_iio_dev(dev); > > - struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + struct stm32_timer_trigger *priv = dev_get_drvdata(dev); > > int i; > > > > for (i = 0; i < ARRAY_SIZE(master_mode_table); i++) { > > @@ -275,6 +291,216 @@ static int stm32_setup_iio_triggers(struct stm32_timer_trigger *priv) > > return 0; > > } > > > > +static int stm32_trigger_read_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, > > + int *val, int *val2, long mask) > I really don't like the naming as trigger_read_raw. Lets just > call it counter_read_raw and then it 'feels' much nicer ;) > > The driver is becoming a two part one with a trigger and a counter > driver (and links between them). Lets let the naming reflect that. > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_RAW: > > + { > > + u32 cnt; > > + > > + regmap_read(priv->regmap, TIM_CNT, &cnt); > > + *val = cnt; > > + > > + return IIO_VAL_INT; > > + } > > + case IIO_CHAN_INFO_SCALE: > > + { > > + u32 smcr; > > + > > + regmap_read(priv->regmap, TIM_SMCR, &smcr); > > + smcr &= TIM_SMCR_SMS; > > + > > + /* return scale only if quadrature mode is selected */ > > + if (smcr != 3) > > + return -EINVAL; > Why not return a scale of unity rather than an error? (which will confuse > users). > > + > > + /* fixed scale */ > > + *val = 1; > > + *val2 = 2; > > + return IIO_VAL_FRACTIONAL_LOG2; > > + } > > + } > > + > > + return -EINVAL; > > +} > > + > > +static int stm32_trigger_write_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, > > + int val, int val2, long mask) > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_RAW: > > + regmap_write(priv->regmap, TIM_CNT, val); > > + > > + return IIO_VAL_INT; > > + case IIO_CHAN_INFO_SCALE: > > + /* fixed scale */ > > + return -EINVAL; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static const struct iio_info stm32_trigger_info = { > > + .driver_module = THIS_MODULE, > > + .read_raw = stm32_trigger_read_raw, > > + .write_raw = stm32_trigger_write_raw > > +}; > > + > > +static const char *const stm32_quadrature_modes[] = { > > + "channel_A", > > + "channel_B", > > + "quadrature", > > +}; > > + > > +static int stm32_set_quadrature_mode(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + unsigned int mode) > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + > > + regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, mode + 1); > > + > > + return 0; > > +} > > + > > +static int stm32_get_quadrature_mode(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan) > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + u32 smcr; > > + > > + regmap_read(priv->regmap, TIM_SMCR, &smcr); > > + smcr &= TIM_SMCR_SMS; > > + > > + return smcr - 1; > > +} > > + > > +static const struct iio_enum stm32_quadrature_mode_enum = { > > + .items = stm32_quadrature_modes, > > + .num_items = ARRAY_SIZE(stm32_quadrature_modes), > > + .set = stm32_set_quadrature_mode, > > + .get = stm32_get_quadrature_mode > > +}; > > + > > +static const char *const stm32_count_direction_states[] = { > > + "up", > > + "down" > > +}; > > + > > +static int stm32_set_count_direction(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + unsigned int mode) > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + > > + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_DIR, mode); > > + > > + return 0; > > +} > > + > > +static int stm32_get_count_direction(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan) > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + u32 cr1; > > + > > + regmap_read(priv->regmap, TIM_CR1, &cr1); > > + > > + return (cr1 & TIM_CR1_DIR); > > +} > > + > > +static const struct iio_enum stm32_count_direction_enum = { > > + .items = stm32_count_direction_states, > > + .num_items = ARRAY_SIZE(stm32_count_direction_states), > > + .set = stm32_set_count_direction, > > + .get = stm32_get_count_direction > > +}; > > + > > +static ssize_t stm32_count_get_preset(struct iio_dev *indio_dev, > > + uintptr_t private, > > + const struct iio_chan_spec *chan, > > + char *buf) > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + u32 arr; > > + > > + regmap_read(priv->regmap, TIM_ARR, &arr); > > + > > + return snprintf(buf, PAGE_SIZE, "%u\n", arr); > > +} > > + > > +static ssize_t stm32_count_set_preset(struct iio_dev *indio_dev, > > + uintptr_t private, > > + const struct iio_chan_spec *chan, > > + const char *buf, size_t len) > > +{ > > + struct stm32_timer_trigger *priv = iio_priv(indio_dev); > > + unsigned int preset; > > + int ret; > > + > > + ret = kstrtouint(buf, 0, &preset); > > + if (ret) > > + return ret; > > + > > + regmap_write(priv->regmap, TIM_ARR, preset); > > + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE); > > + > > + return len; > > +} > > + > > +static const struct iio_chan_spec_ext_info stm32_trigger_count_info[] = { > > + { > > + .name = "preset", > > + .shared = IIO_SEPARATE, > > + .read = stm32_count_get_preset, > > + .write = stm32_count_set_preset > > + }, > > + IIO_ENUM("count_direction", IIO_SEPARATE, &stm32_count_direction_enum), > > + IIO_ENUM_AVAILABLE("count_direction", &stm32_count_direction_enum), > > + IIO_ENUM("quadrature_mode", IIO_SEPARATE, &stm32_quadrature_mode_enum), > > + IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_quadrature_mode_enum), > > + {} > > +}; > > + > > +static const struct iio_chan_spec stm32_trigger_channel = { > > + .type = IIO_COUNT, > > + .channel = 0, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), > > + .ext_info = stm32_trigger_count_info, > > + .indexed = 1 > > +}; > > + > > +static struct stm32_timer_trigger *stm32_setup_iio_device(struct device *dev) > That wins the slightly overly generic name! There are several other > stm32 iio devices already. setup_counter_device maybe? > > +{ > > + struct iio_dev *indio_dev; > > + int ret; > > + > > + indio_dev = devm_iio_device_alloc(dev, > > + sizeof(struct stm32_timer_trigger)); > > + if (!indio_dev) > > + return NULL; > > + > > + indio_dev->name = dev_name(dev); > > + indio_dev->dev.parent = dev; > > + indio_dev->info = &stm32_trigger_info; > > + indio_dev->num_channels = 1; > > + indio_dev->channels = &stm32_trigger_channel; > > + indio_dev->dev.of_node = dev->of_node; > > + > > + ret = devm_iio_device_register(dev, indio_dev); > > + if (ret) > > + return NULL; > > + > > + return iio_priv(indio_dev); > > +} > > + > > /** > > * is_stm32_timer_trigger > > * @trig: trigger to be checked > > @@ -299,10 +525,15 @@ static int stm32_timer_trigger_probe(struct platform_device *pdev) > > if (of_property_read_u32(dev->of_node, "reg", &index)) > > return -EINVAL; > > > > - if (index >= ARRAY_SIZE(triggers_table)) > > + if (index >= ARRAY_SIZE(triggers_table) || > > + index >= ARRAY_SIZE(valids_table)) > > return -EINVAL; > > > > - priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > > + /* Create an IIO device only if we have triggers to be validated */ > > + if (*valids_table[index]) > > + priv = stm32_setup_iio_device(dev); > > + else > > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > > > > if (!priv) > > return -ENOMEM; > > @@ -312,6 +543,7 @@ static int stm32_timer_trigger_probe(struct platform_device *pdev) > > priv->clk = ddata->clk; > > priv->max_arr = ddata->max_arr; > > priv->triggers = triggers_table[index]; > > + priv->valids = valids_table[index]; > > > > ret = stm32_setup_iio_triggers(priv); > > if (ret) > > diff --git a/include/linux/mfd/stm32-timers.h b/include/linux/mfd/stm32-timers.h > > index d030004..4a0abbc 100644 > > --- a/include/linux/mfd/stm32-timers.h > > +++ b/include/linux/mfd/stm32-timers.h > > @@ -21,6 +21,7 @@ > > #define TIM_CCMR1 0x18 /* Capt/Comp 1 Mode Reg */ > > #define TIM_CCMR2 0x1C /* Capt/Comp 2 Mode Reg */ > > #define TIM_CCER 0x20 /* Capt/Comp Enable Reg */ > > +#define TIM_CNT 0x24 /* Counter */ > > #define TIM_PSC 0x28 /* Prescaler */ > > #define TIM_ARR 0x2c /* Auto-Reload Register */ > > #define TIM_CCR1 0x34 /* Capt/Comp Register 1 */ > > @@ -30,6 +31,7 @@ > > #define TIM_BDTR 0x44 /* Break and Dead-Time Reg */ > > > > #define TIM_CR1_CEN BIT(0) /* Counter Enable */ > > +#define TIM_CR1_DIR BIT(4) /* Counter Direction */ > > #define TIM_CR1_ARPE BIT(7) /* Auto-reload Preload Ena */ > > #define TIM_CR2_MMS (BIT(4) | BIT(5) | BIT(6)) /* Master mode selection */ > > #define TIM_SMCR_SMS (BIT(0) | BIT(1) | BIT(2)) /* Slave mode selection */ > > > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
