| Message ID | 1364568853-18561-2-git-send-email-ludovic.desroches@atmel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/29/2013 02:54 PM, ludovic.desroches@atmel.com wrote: > From: Ludovic Desroches <ludovic.desroches@atmel.com> > > at91 adc offers the choice between two resolutions: low and high. > The low and high resolution values depends on adc IP version, as many IP > properties have been exposed through device tree, these settings have also > been added to the dt bindings. > > Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Applied to the togreg branch of iio.git > --- > .../devicetree/bindings/arm/atmel-adc.txt | 11 ++++ > drivers/iio/adc/at91_adc.c | 74 ++++++++++++++++++++-- > 2 files changed, 81 insertions(+), 4 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt > index c63097d..fd2d69e 100644 > --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt > +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt > @@ -14,9 +14,17 @@ Required properties: > - atmel,adc-status-register: Offset of the Interrupt Status Register > - atmel,adc-trigger-register: Offset of the Trigger Register > - atmel,adc-vref: Reference voltage in millivolts for the conversions > + - atmel,adc-res: List of resolution in bits supported by the ADC. List size > + must be two at least. > + - atmel,adc-res-names: Contains one identifier string for each resolution > + in atmel,adc-res property. "lowres" and "highres" > + identifiers are required. > > Optional properties: > - atmel,adc-use-external: Boolean to enable of external triggers > + - atmel,adc-use-res: String corresponding to an identifier from > + atmel,adc-res-names property. If not specified, the highest > + resolution will be used. > > Optional trigger Nodes: > - Required properties: > @@ -40,6 +48,9 @@ adc0: adc@fffb0000 { > atmel,adc-trigger-register = <0x08>; > atmel,adc-use-external; > atmel,adc-vref = <3300>; > + atmel,adc-res = <8 10>; > + atmel,adc-res-names = "lowres", "highres"; > + atmel,adc-use-res = "lowres"; > > trigger@0 { > trigger-name = "external-rising"; > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c > index 83c836b..a7ad3e7 100644 > --- a/drivers/iio/adc/at91_adc.c > +++ b/drivers/iio/adc/at91_adc.c > @@ -57,6 +57,8 @@ struct at91_adc_state { > u32 trigger_number; > bool use_external; > u32 vref_mv; > + u32 res; /* resolution used for convertions */ > + bool low_res; /* the resolution corresponds to the lowest one */ > wait_queue_head_t wq_data_avail; > }; > > @@ -138,7 +140,7 @@ static int at91_adc_channel_init(struct iio_dev *idev) > chan->channel = bit; > chan->scan_index = idx; > chan->scan_type.sign = 'u'; > - chan->scan_type.realbits = 10; > + chan->scan_type.realbits = st->res; > chan->scan_type.storagebits = 16; > chan->info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT | > IIO_CHAN_INFO_RAW_SEPARATE_BIT; > @@ -372,6 +374,59 @@ static int at91_adc_read_raw(struct iio_dev *idev, > return -EINVAL; > } > > +static int at91_adc_of_get_resolution(struct at91_adc_state *st, > + struct platform_device *pdev) > +{ > + struct iio_dev *idev = iio_priv_to_dev(st); > + struct device_node *np = pdev->dev.of_node; > + int count, i, ret = 0; > + char *res_name, *s; > + u32 *resolutions; > + > + count = of_property_count_strings(np, "atmel,adc-res-names"); > + if (count < 2) { > + dev_err(&idev->dev, "You must specified at least two resolution names for " > + "adc-res-names property in the DT\n"); > + return count; > + } > + > + resolutions = kmalloc(count * sizeof(*resolutions), GFP_KERNEL); > + if (!resolutions) > + return -ENOMEM; > + > + if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) { > + dev_err(&idev->dev, "Missing adc-res property in the DT.\n"); > + ret = -ENODEV; > + goto ret; > + } > + > + if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name)) > + res_name = "highres"; > + > + for (i = 0; i < count; i++) { > + if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s)) > + continue; > + > + if (strcmp(res_name, s)) > + continue; > + > + st->res = resolutions[i]; > + if (!strcmp(res_name, "lowres")) > + st->low_res = true; > + else > + st->low_res = false; > + > + dev_info(&idev->dev, "Resolution used: %u bits\n", st->res); > + goto ret; > + } > + > + dev_err(&idev->dev, "There is no resolution for %s\n", res_name); > + > +ret: > + kfree(resolutions); > + return ret; > +} > + > static int at91_adc_probe_dt(struct at91_adc_state *st, > struct platform_device *pdev) > { > @@ -415,6 +470,10 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, > } > st->vref_mv = prop; > > + ret = at91_adc_of_get_resolution(st, pdev); > + if (ret) > + goto error_ret; > + > st->registers = devm_kzalloc(&idev->dev, > sizeof(struct at91_adc_reg_desc), > GFP_KERNEL); > @@ -628,9 +687,16 @@ static int at91_adc_probe(struct platform_device *pdev) > */ > ticks = round_up((st->startup_time * adc_clk / > 1000000) - 1, 8) / 8; > - at91_adc_writel(st, AT91_ADC_MR, > - (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) | > - (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP)); > + > + if (st->low_res) > + at91_adc_writel(st, AT91_ADC_MR, > + AT91_ADC_LOWRES | > + (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) | > + (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP)); > + else > + at91_adc_writel(st, AT91_ADC_MR, > + (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) | > + (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP)); > > /* Setup the ADC channels available on the board */ > ret = at91_adc_channel_init(idev); >
diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt index c63097d..fd2d69e 100644 --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt @@ -14,9 +14,17 @@ Required properties: - atmel,adc-status-register: Offset of the Interrupt Status Register - atmel,adc-trigger-register: Offset of the Trigger Register - atmel,adc-vref: Reference voltage in millivolts for the conversions + - atmel,adc-res: List of resolution in bits supported by the ADC. List size + must be two at least. + - atmel,adc-res-names: Contains one identifier string for each resolution + in atmel,adc-res property. "lowres" and "highres" + identifiers are required. Optional properties: - atmel,adc-use-external: Boolean to enable of external triggers + - atmel,adc-use-res: String corresponding to an identifier from + atmel,adc-res-names property. If not specified, the highest + resolution will be used. Optional trigger Nodes: - Required properties: @@ -40,6 +48,9 @@ adc0: adc@fffb0000 { atmel,adc-trigger-register = <0x08>; atmel,adc-use-external; atmel,adc-vref = <3300>; + atmel,adc-res = <8 10>; + atmel,adc-res-names = "lowres", "highres"; + atmel,adc-use-res = "lowres"; trigger@0 { trigger-name = "external-rising"; diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index 83c836b..a7ad3e7 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -57,6 +57,8 @@ struct at91_adc_state { u32 trigger_number; bool use_external; u32 vref_mv; + u32 res; /* resolution used for convertions */ + bool low_res; /* the resolution corresponds to the lowest one */ wait_queue_head_t wq_data_avail; }; @@ -138,7 +140,7 @@ static int at91_adc_channel_init(struct iio_dev *idev) chan->channel = bit; chan->scan_index = idx; chan->scan_type.sign = 'u'; - chan->scan_type.realbits = 10; + chan->scan_type.realbits = st->res; chan->scan_type.storagebits = 16; chan->info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT | IIO_CHAN_INFO_RAW_SEPARATE_BIT; @@ -372,6 +374,59 @@ static int at91_adc_read_raw(struct iio_dev *idev, return -EINVAL; } +static int at91_adc_of_get_resolution(struct at91_adc_state *st, + struct platform_device *pdev) +{ + struct iio_dev *idev = iio_priv_to_dev(st); + struct device_node *np = pdev->dev.of_node; + int count, i, ret = 0; + char *res_name, *s; + u32 *resolutions; + + count = of_property_count_strings(np, "atmel,adc-res-names"); + if (count < 2) { + dev_err(&idev->dev, "You must specified at least two resolution names for " + "adc-res-names property in the DT\n"); + return count; + } + + resolutions = kmalloc(count * sizeof(*resolutions), GFP_KERNEL); + if (!resolutions) + return -ENOMEM; + + if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) { + dev_err(&idev->dev, "Missing adc-res property in the DT.\n"); + ret = -ENODEV; + goto ret; + } + + if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name)) + res_name = "highres"; + + for (i = 0; i < count; i++) { + if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s)) + continue; + + if (strcmp(res_name, s)) + continue; + + st->res = resolutions[i]; + if (!strcmp(res_name, "lowres")) + st->low_res = true; + else + st->low_res = false; + + dev_info(&idev->dev, "Resolution used: %u bits\n", st->res); + goto ret; + } + + dev_err(&idev->dev, "There is no resolution for %s\n", res_name); + +ret: + kfree(resolutions); + return ret; +} + static int at91_adc_probe_dt(struct at91_adc_state *st, struct platform_device *pdev) { @@ -415,6 +470,10 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, } st->vref_mv = prop; + ret = at91_adc_of_get_resolution(st, pdev); + if (ret) + goto error_ret; + st->registers = devm_kzalloc(&idev->dev, sizeof(struct at91_adc_reg_desc), GFP_KERNEL); @@ -628,9 +687,16 @@ static int at91_adc_probe(struct platform_device *pdev) */ ticks = round_up((st->startup_time * adc_clk / 1000000) - 1, 8) / 8; - at91_adc_writel(st, AT91_ADC_MR, - (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) | - (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP)); + + if (st->low_res) + at91_adc_writel(st, AT91_ADC_MR, + AT91_ADC_LOWRES | + (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) | + (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP)); + else + at91_adc_writel(st, AT91_ADC_MR, + (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) | + (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP)); /* Setup the ADC channels available on the board */ ret = at91_adc_channel_init(idev);