Re: [PATCH 1/1] iio: adc: stm32-adc: add id registers support

From: Jonathan Cameron
Date: Sun Sep 18 2022 - 11:31:58 EST


On Fri, 16 Sep 2022 15:43:58 +0200
Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx> wrote:

> On 9/15/22 15:54, Olivier Moysan wrote:
> > Add support of identification registers to STM32 ADC.
> >
> > By default the ADC hardware instance number is retrieved from
> > the compatible configuration data. Get the available ADC number
> > per ADC block, from hardware configuration register,
> > when this register exists.
> >
> > Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxxxxxxx>
>
> Hi Olivier,
>
> You can add my:
> Reviewed-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>

Applied to the togreg branch of iio.git and pushed out as testing for
0-day to see if it can find anything we missed.

Thanks,

Jonathan

>
> Thanks and Best Regards,
> Fabrice
>
> > ---
> > drivers/iio/adc/stm32-adc-core.c | 59 ++++++++++++++++++++++++++++++--
> > drivers/iio/adc/stm32-adc-core.h | 31 +++++++++++++++++
> > 2 files changed, 87 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
> > index 1ce52af3fe8b..81d5db91c67b 100644
> > --- a/drivers/iio/adc/stm32-adc-core.c
> > +++ b/drivers/iio/adc/stm32-adc-core.c
> > @@ -9,6 +9,7 @@
> > *
> > */
> >
> > +#include <linux/bitfield.h>
> > #include <linux/clk.h>
> > #include <linux/interrupt.h>
> > #include <linux/irqchip/chained_irq.h>
> > @@ -62,6 +63,7 @@ struct stm32_adc_priv;
> > * @regs: common registers for all instances
> > * @clk_sel: clock selection routine
> > * @max_clk_rate_hz: maximum analog clock rate (Hz, from datasheet)
> > + * @ipid: adc identification number
> > * @has_syscfg: SYSCFG capability flags
> > * @num_irqs: number of interrupt lines
> > * @num_adcs: maximum number of ADC instances in the common registers
> > @@ -70,6 +72,7 @@ struct stm32_adc_priv_cfg {
> > const struct stm32_adc_common_regs *regs;
> > int (*clk_sel)(struct platform_device *, struct stm32_adc_priv *);
> > u32 max_clk_rate_hz;
> > + u32 ipid;
> > unsigned int has_syscfg;
> > unsigned int num_irqs;
> > unsigned int num_adcs;
> > @@ -78,6 +81,7 @@ struct stm32_adc_priv_cfg {
> > /**
> > * struct stm32_adc_priv - stm32 ADC core private data
> > * @irq: irq(s) for ADC block
> > + * @nb_adc_max: actual maximum number of instance per ADC block
> > * @domain: irq domain reference
> > * @aclk: clock reference for the analog circuitry
> > * @bclk: bus clock common for all ADCs, depends on part used
> > @@ -95,6 +99,7 @@ struct stm32_adc_priv_cfg {
> > */
> > struct stm32_adc_priv {
> > int irq[STM32_ADC_MAX_ADCS];
> > + unsigned int nb_adc_max;
> > struct irq_domain *domain;
> > struct clk *aclk;
> > struct clk *bclk;
> > @@ -354,7 +359,7 @@ static void stm32_adc_irq_handler(struct irq_desc *desc)
> > * before invoking the interrupt handler (e.g. call ISR only for
> > * IRQ-enabled ADCs).
> > */
> > - for (i = 0; i < priv->cfg->num_adcs; i++) {
> > + for (i = 0; i < priv->nb_adc_max; i++) {
> > if ((status & priv->cfg->regs->eoc_msk[i] &&
> > stm32_adc_eoc_enabled(priv, i)) ||
> > (status & priv->cfg->regs->ovr_msk[i]))
> > @@ -424,7 +429,7 @@ static void stm32_adc_irq_remove(struct platform_device *pdev,
> > int hwirq;
> > unsigned int i;
> >
> > - for (hwirq = 0; hwirq < STM32_ADC_MAX_ADCS; hwirq++)
> > + for (hwirq = 0; hwirq < priv->nb_adc_max; hwirq++)
> > irq_dispose_mapping(irq_find_mapping(priv->domain, hwirq));
> > irq_domain_remove(priv->domain);
> >
> > @@ -642,6 +647,49 @@ static int stm32_adc_core_switches_probe(struct device *dev,
> > return 0;
> > }
> >
> > +static int stm32_adc_probe_identification(struct platform_device *pdev,
> > + struct stm32_adc_priv *priv)
> > +{
> > + struct device_node *np = pdev->dev.of_node;
> > + struct device_node *child;
> > + const char *compat;
> > + int ret, count = 0;
> > + u32 id, val;
> > +
> > + if (!priv->cfg->ipid)
> > + return 0;
> > +
> > + id = FIELD_GET(STM32MP1_IPIDR_MASK,
> > + readl_relaxed(priv->common.base + STM32MP1_ADC_IPDR));
> > + if (id != priv->cfg->ipid) {
> > + dev_err(&pdev->dev, "Unexpected IP version: 0x%x", id);
> > + return -EINVAL;
> > + }
> > +
> > + for_each_child_of_node(np, child) {
> > + ret = of_property_read_string(child, "compatible", &compat);
> > + if (ret)
> > + continue;
> > + /* Count child nodes with stm32 adc compatible */
> > + if (strstr(compat, "st,stm32") && strstr(compat, "adc"))
> > + count++;
> > + }
> > +
> > + val = readl_relaxed(priv->common.base + STM32MP1_ADC_HWCFGR0);
> > + priv->nb_adc_max = FIELD_GET(STM32MP1_ADCNUM_MASK, val);
> > + if (count > priv->nb_adc_max) {
> > + dev_err(&pdev->dev, "Unexpected child number: %d", count);
> > + return -EINVAL;
> > + }
> > +
> > + val = readl_relaxed(priv->common.base + STM32MP1_ADC_VERR);
> > + dev_dbg(&pdev->dev, "ADC version: %lu.%lu\n",
> > + FIELD_GET(STM32MP1_MAJREV_MASK, val),
> > + FIELD_GET(STM32MP1_MINREV_MASK, val));
> > +
> > + return 0;
> > +}
> > +
> > static int stm32_adc_probe(struct platform_device *pdev)
> > {
> > struct stm32_adc_priv *priv;
> > @@ -661,6 +709,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
> >
> > priv->cfg = (const struct stm32_adc_priv_cfg *)
> > of_match_device(dev->driver->of_match_table, dev)->data;
> > + priv->nb_adc_max = priv->cfg->num_adcs;
> > spin_lock_init(&priv->common.lock);
> >
> > res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > @@ -703,6 +752,10 @@ static int stm32_adc_probe(struct platform_device *pdev)
> > if (ret)
> > goto err_pm_stop;
> >
> > + ret = stm32_adc_probe_identification(pdev, priv);
> > + if (ret < 0)
> > + goto err_hw_stop;
> > +
> > ret = regulator_get_voltage(priv->vref);
> > if (ret < 0) {
> > dev_err(&pdev->dev, "vref get voltage failed, %d\n", ret);
> > @@ -811,8 +864,8 @@ static const struct stm32_adc_priv_cfg stm32mp1_adc_priv_cfg = {
> > .clk_sel = stm32h7_adc_clk_sel,
> > .max_clk_rate_hz = 36000000,
> > .has_syscfg = HAS_VBOOSTER | HAS_ANASWVDD,
> > + .ipid = STM32MP15_IPIDR_NUMBER,
> > .num_irqs = 2,
> > - .num_adcs = 2,
> > };
> >
> > static const struct of_device_id stm32_adc_of_match[] = {
> > diff --git a/drivers/iio/adc/stm32-adc-core.h b/drivers/iio/adc/stm32-adc-core.h
> > index faedf7a49555..2118ef63843d 100644
> > --- a/drivers/iio/adc/stm32-adc-core.h
> > +++ b/drivers/iio/adc/stm32-adc-core.h
> > @@ -24,6 +24,7 @@
> > * | 0x300 | Master & Slave common regs |
> > * --------------------------------------------------------
> > */
> > +/* Maximum ADC instances number per ADC block for all supported SoCs */
> > #define STM32_ADC_MAX_ADCS 3
> > #define STM32_ADC_OFFSET 0x100
> > #define STM32_ADCX_COMN_OFFSET 0x300
> > @@ -105,6 +106,12 @@
> > /* STM32MP1 - ADC2 instance option register */
> > #define STM32MP1_ADC2_OR 0xD0
> >
> > +/* STM32MP1 - Identification registers */
> > +#define STM32MP1_ADC_HWCFGR0 0x3F0
> > +#define STM32MP1_ADC_VERR 0x3F4
> > +#define STM32MP1_ADC_IPDR 0x3F8
> > +#define STM32MP1_ADC_SIDR 0x3FC
> > +
> > /* STM32H7 - common registers for all ADC instances */
> > #define STM32H7_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00)
> > #define STM32H7_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x08)
> > @@ -181,6 +188,30 @@ enum stm32h7_adc_dmngt {
> > /* STM32MP1_ADC2_OR - bit fields */
> > #define STM32MP1_VDDCOREEN BIT(0)
> >
> > +/* STM32MP1_ADC_HWCFGR0 - bit fields */
> > +#define STM32MP1_ADCNUM_SHIFT 0
> > +#define STM32MP1_ADCNUM_MASK GENMASK(3, 0)
> > +#define STM32MP1_MULPIPE_SHIFT 4
> > +#define STM32MP1_MULPIPE_MASK GENMASK(7, 4)
> > +#define STM32MP1_OPBITS_SHIFT 8
> > +#define STM32MP1_OPBITS_MASK GENMASK(11, 8)
> > +#define STM32MP1_IDLEVALUE_SHIFT 12
> > +#define STM32MP1_IDLEVALUE_MASK GENMASK(15, 12)
> > +
> > +/* STM32MP1_ADC_VERR - bit fields */
> > +#define STM32MP1_MINREV_SHIFT 0
> > +#define STM32MP1_MINREV_MASK GENMASK(3, 0)
> > +#define STM32MP1_MAJREV_SHIFT 4
> > +#define STM32MP1_MAJREV_MASK GENMASK(7, 4)
> > +
> > +/* STM32MP1_ADC_IPDR - bit fields */
> > +#define STM32MP1_IPIDR_MASK GENMASK(31, 0)
> > +
> > +/* STM32MP1_ADC_SIDR - bit fields */
> > +#define STM32MP1_SIDR_MASK GENMASK(31, 0)
> > +
> > +#define STM32MP15_IPIDR_NUMBER 0x00110005
> > +
> > /**
> > * struct stm32_adc_common - stm32 ADC driver common data (for all instances)
> > * @base: control registers base cpu addr