[PATCH v2 09/15] iio: adc: rzg2l_adc: Prepare for the addition of RZ/G3S support

Claudiu
2024-12-06T11:14:11Z

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

The ADC IP available on the RZ/G3S differs slightly from the one found on
the RZ/G2L. The identified differences are as follows:
- different number of channels (one being used for temperature conversion);
consequently, various registers differ
- different default sampling periods
- the RZ/G3S variant lacks the ADVIC register.

To accommodate these differences, the rzg2l_adc driver has been updated by
introducing the struct rzg2l_adc_hw_params, which encapsulates the
hardware-specific differences between the IP variants. A pointer to an
object of type struct rzg2l_adc_hw_params is embedded in
struct rzg2l_adc_data.

Additionally, the completion member of struct rzg2l_adc_data was relocated
to avoid potential padding, if any.

The code has been adjusted to utilize hardware-specific parameters stored
in the new structure instead of relying on plain macros.

The check of chan->channel in rzg2l_adc_read_raw() function, against the
driver specific mask was removed as the subsystem should have already
been done this before reaching the rzg2l_adc_read_raw() function. Along
with it the local variable ch was dropped as chan->channel could be used
instead.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v2:
- kept the RZG2L_ADC_MAX_CHANNELS as suggested in the review process;
along with it, last_val[] is now again statically alocated; code
from v1 around last_val has been adjusted to align with the new
approach
- dropped ch variable from rzg2l_adc_read_raw() and adjusted the
patch description to reflect it.

drivers/iio/adc/rzg2l_adc.c | 87 +++++++++++++++++++++++++------------
1 file changed, 59 insertions(+), 28 deletions(-)

diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
index c3f9f95cdbba..6740912f83c5 100644
--- a/drivers/iio/adc/rzg2l_adc.c
+++ b/drivers/iio/adc/rzg2l_adc.c
@@ -33,20 +33,15 @@
#define RZG2L_ADM1_MS BIT(2)
#define RZG2L_ADM1_BS BIT(4)
#define RZG2L_ADM1_EGA_MASK GENMASK(13, 12)
-#define RZG2L_ADM2_CHSEL_MASK GENMASK(7, 0)
#define RZG2L_ADM3_ADIL_MASK GENMASK(31, 24)
#define RZG2L_ADM3_ADCMP_MASK GENMASK(23, 16)
-#define RZG2L_ADM3_ADCMP_E FIELD_PREP(RZG2L_ADM3_ADCMP_MASK, 0xe)
-#define RZG2L_ADM3_ADSMP_MASK GENMASK(15, 0)

#define RZG2L_ADINT 0x20
-#define RZG2L_ADINT_INTEN_MASK GENMASK(7, 0)
#define RZG2L_ADINT_CSEEN BIT(16)
#define RZG2L_ADINT_INTS BIT(31)

#define RZG2L_ADSTS 0x24
#define RZG2L_ADSTS_CSEST BIT(16)
-#define RZG2L_ADSTS_INTST_MASK GENMASK(7, 0)

#define RZG2L_ADIVC 0x28
#define RZG2L_ADIVC_DIVADC_MASK GENMASK(8, 0)
@@ -57,12 +52,27 @@
#define RZG2L_ADCR(n) (0x30 + ((n) * 0x4))
#define RZG2L_ADCR_AD_MASK GENMASK(11, 0)

-#define RZG2L_ADSMP_DEFAULT_SAMPLING 0x578
-
#define RZG2L_ADC_MAX_CHANNELS 8
-#define RZG2L_ADC_CHN_MASK 0x7
#define RZG2L_ADC_TIMEOUT usecs_to_jiffies(1 * 4)

+/**
+ * struct rzg2l_adc_hw_params - ADC hardware specific parameters
+ * @default_adsmp: default ADC sampling period (see ADM3 register)
+ * @adsmp_mask: ADC sampling period mask (see ADM3 register)
+ * @adint_inten_mask: conversion end interrupt mask (see ADINT register)
+ * @default_adcmp: default ADC cmp (see ADM3 register)
+ * @num_channels: number of supported channels
+ * @adivc: specifies if ADVIC register is available
+ */
+struct rzg2l_adc_hw_params {
+ u16 default_adsmp;
+ u16 adsmp_mask;
+ u16 adint_inten_mask;
+ u8 default_adcmp;
+ u8 num_channels;
+ bool adivc;
+};
+
struct rzg2l_adc_data {
const struct iio_chan_spec *channels;
u8 num_channels;
@@ -72,8 +82,9 @@ struct rzg2l_adc {
void __iomem *base;
struct reset_control *presetn;
struct reset_control *adrstn;
- struct completion completion;
const struct rzg2l_adc_data *data;
+ const struct rzg2l_adc_hw_params *hw_params;
+ struct completion completion;
struct mutex lock;
u16 last_val[RZG2L_ADC_MAX_CHANNELS];
};
@@ -154,6 +165,7 @@ static void rzg2l_set_trigger(struct rzg2l_adc *adc)

static int rzg2l_adc_conversion_setup(struct rzg2l_adc *adc, u8 ch)
{
+ const struct rzg2l_adc_hw_params *hw_params = adc->hw_params;
u32 reg;

if (rzg2l_adc_readl(adc, RZG2L_ADM(0)) & RZG2L_ADM0_ADBSY)
@@ -163,7 +175,7 @@ static int rzg2l_adc_conversion_setup(struct rzg2l_adc *adc, u8 ch)

/* Select analog input channel subjected to conversion. */
reg = rzg2l_adc_readl(adc, RZG2L_ADM(2));
- reg &= ~RZG2L_ADM2_CHSEL_MASK;
+ reg &= ~GENMASK(hw_params->num_channels - 1, 0);
reg |= BIT(ch);
rzg2l_adc_writel(adc, RZG2L_ADM(2), reg);

@@ -175,7 +187,7 @@ static int rzg2l_adc_conversion_setup(struct rzg2l_adc *adc, u8 ch)
*/
reg = rzg2l_adc_readl(adc, RZG2L_ADINT);
reg &= ~RZG2L_ADINT_INTS;
- reg &= ~RZG2L_ADINT_INTEN_MASK;
+ reg &= ~hw_params->adint_inten_mask;
reg |= (RZG2L_ADINT_CSEEN | BIT(ch));
rzg2l_adc_writel(adc, RZG2L_ADINT, reg);

@@ -184,6 +196,7 @@ static int rzg2l_adc_conversion_setup(struct rzg2l_adc *adc, u8 ch)

static int rzg2l_adc_conversion(struct iio_dev *indio_dev, struct rzg2l_adc *adc, u8 ch)
{
+ const struct rzg2l_adc_hw_params *hw_params = adc->hw_params;
struct device *dev = indio_dev->dev.parent;
int ret;

@@ -201,7 +214,7 @@ static int rzg2l_adc_conversion(struct iio_dev *indio_dev, struct rzg2l_adc *adc

if (!wait_for_completion_timeout(&adc->completion, RZG2L_ADC_TIMEOUT)) {
rzg2l_adc_writel(adc, RZG2L_ADINT,
- rzg2l_adc_readl(adc, RZG2L_ADINT) & ~RZG2L_ADINT_INTEN_MASK);
+ rzg2l_adc_readl(adc, RZG2L_ADINT) & ~hw_params->adint_inten_mask);
ret = -ETIMEDOUT;
}

@@ -219,7 +232,6 @@ static int rzg2l_adc_read_raw(struct iio_dev *indio_dev,
{
struct rzg2l_adc *adc = iio_priv(indio_dev);
int ret;
- u8 ch;

switch (mask) {
case IIO_CHAN_INFO_RAW: {
@@ -228,12 +240,11 @@ static int rzg2l_adc_read_raw(struct iio_dev *indio_dev,

guard(mutex)(&adc->lock);

- ch = chan->channel & RZG2L_ADC_CHN_MASK;
- ret = rzg2l_adc_conversion(indio_dev, adc, ch);
+ ret = rzg2l_adc_conversion(indio_dev, adc, chan->channel);
if (ret)
return ret;

- *val = adc->last_val[ch];
+ *val = adc->last_val[chan->channel];

return IIO_VAL_INT;
}
@@ -258,6 +269,7 @@ static const struct iio_info rzg2l_adc_iio_info = {
static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)
{
struct rzg2l_adc *adc = dev_id;
+ const struct rzg2l_adc_hw_params *hw_params = adc->hw_params;
unsigned long intst;
u32 reg;
int ch;
@@ -270,11 +282,11 @@ static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)
return IRQ_HANDLED;
}

- intst = reg & RZG2L_ADSTS_INTST_MASK;
+ intst = reg & GENMASK(hw_params->num_channels - 1, 0);
if (!intst)
return IRQ_NONE;

- for_each_set_bit(ch, &intst, RZG2L_ADC_MAX_CHANNELS)
+ for_each_set_bit(ch, &intst, hw_params->num_channels)
adc->last_val[ch] = rzg2l_adc_readl(adc, RZG2L_ADCR(ch)) & RZG2L_ADCR_AD_MASK;

/* clear the channel interrupt */
@@ -287,6 +299,7 @@ static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)

static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l_adc *adc)
{
+ const struct rzg2l_adc_hw_params *hw_params = adc->hw_params;
struct iio_chan_spec *chan_array;
struct rzg2l_adc_data *data;
unsigned int channel;
@@ -302,7 +315,7 @@ static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l
if (!num_channels)
return dev_err_probe(&pdev->dev, -ENODEV, "no channel children\n");

- if (num_channels > RZG2L_ADC_MAX_CHANNELS)
+ if (num_channels > hw_params->num_channels)
return dev_err_probe(&pdev->dev, -EINVAL, "num of channel children out of range\n");

chan_array = devm_kcalloc(&pdev->dev, num_channels, sizeof(*chan_array),
@@ -316,7 +329,7 @@ static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l
if (ret)
return ret;

- if (channel >= RZG2L_ADC_MAX_CHANNELS)
+ if (channel >= hw_params->num_channels)
return -EINVAL;

chan_array[i].type = IIO_VOLTAGE;
@@ -336,6 +349,7 @@ static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l

static int rzg2l_adc_hw_init(struct device *dev, struct rzg2l_adc *adc)
{
+ const struct rzg2l_adc_hw_params *hw_params = adc->hw_params;
u32 reg;
int ret;

@@ -353,11 +367,13 @@ static int rzg2l_adc_hw_init(struct device *dev, struct rzg2l_adc *adc)
if (ret)
goto exit_hw_init;

- /* Only division by 4 can be set */
- reg = rzg2l_adc_readl(adc, RZG2L_ADIVC);
- reg &= ~RZG2L_ADIVC_DIVADC_MASK;
- reg |= RZG2L_ADIVC_DIVADC_4;
- rzg2l_adc_writel(adc, RZG2L_ADIVC, reg);
+ if (hw_params->adivc) {
+ /* Only division by 4 can be set */
+ reg = rzg2l_adc_readl(adc, RZG2L_ADIVC);
+ reg &= ~RZG2L_ADIVC_DIVADC_MASK;
+ reg |= RZG2L_ADIVC_DIVADC_4;
+ rzg2l_adc_writel(adc, RZG2L_ADIVC, reg);
+ }

/*
* Setup AMD3
@@ -368,8 +384,10 @@ static int rzg2l_adc_hw_init(struct device *dev, struct rzg2l_adc *adc)
reg = rzg2l_adc_readl(adc, RZG2L_ADM(3));
reg &= ~RZG2L_ADM3_ADIL_MASK;
reg &= ~RZG2L_ADM3_ADCMP_MASK;
- reg &= ~RZG2L_ADM3_ADSMP_MASK;
- reg |= (RZG2L_ADM3_ADCMP_E | RZG2L_ADSMP_DEFAULT_SAMPLING);
+ reg &= ~hw_params->adsmp_mask;
+ reg |= FIELD_PREP(RZG2L_ADM3_ADCMP_MASK, hw_params->default_adcmp) |
+ hw_params->default_adsmp;
+
rzg2l_adc_writel(adc, RZG2L_ADM(3), reg);

exit_hw_init:
@@ -392,6 +410,10 @@ static int rzg2l_adc_probe(struct platform_device *pdev)

adc = iio_priv(indio_dev);

+ adc->hw_params = device_get_match_data(dev);
+ if (!adc->hw_params || adc->hw_params->num_channels > RZG2L_ADC_MAX_CHANNELS)
+ return -EINVAL;
+
ret = rzg2l_adc_parse_properties(pdev, adc);
if (ret)
return ret;
@@ -444,8 +466,17 @@ static int rzg2l_adc_probe(struct platform_device *pdev)
return devm_iio_device_register(dev, indio_dev);
}

+static const struct rzg2l_adc_hw_params rzg2l_hw_params = {
+ .num_channels = 8,
+ .default_adcmp = 0xe,
+ .default_adsmp = 0x578,
+ .adsmp_mask = GENMASK(15, 0),
+ .adint_inten_mask = GENMASK(7, 0),
+ .adivc = true
+};
+
static const struct of_device_id rzg2l_adc_match[] = {
- { .compatible = "renesas,rzg2l-adc",},
+ { .compatible = "renesas,rzg2l-adc", .data = &rzg2l_hw_params },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rzg2l_adc_match);
--
2.39.2