Re: [PATCH V15 6/9] mfd: pm8008: Use i2c_new_dummy_device() API

From: Satya Priya Kakitapalli (Temp)
Date: Mon Jun 27 2022 - 01:08:46 EST


Hi Lee,


On 6/20/2022 4:37 PM, Satya Priya Kakitapalli (Temp) wrote:

On 6/20/2022 1:50 PM, Lee Jones wrote:
On Mon, 20 Jun 2022, Satya Priya Kakitapalli (Temp) wrote:

On 6/17/2022 2:27 AM, Lee Jones wrote:
On Tue, 14 Jun 2022, Satya Priya wrote:

Use i2c_new_dummy_device() to register pm8008-regulator
client present at a different address space, instead of
defining a separate DT node. This avoids calling the probe
twice for the same chip, once for each client pm8008-infra
and pm8008-regulator.

As a part of this define pm8008_regmap_init() to do regmap
init for both the clients and define pm8008_get_regmap() to
pass the regmap to the regulator driver.

Signed-off-by: Satya Priya <quic_c_skakit@xxxxxxxxxxx>
Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
---
Changes in V15:
   - None.

Changes in V14:
   - None.

Changes in V13:
   - None.

   drivers/mfd/qcom-pm8008.c       | 34 ++++++++++++++++++++++++++++++++--
   include/linux/mfd/qcom_pm8008.h |  9 +++++++++
   2 files changed, 41 insertions(+), 2 deletions(-)
   create mode 100644 include/linux/mfd/qcom_pm8008.h

diff --git a/drivers/mfd/qcom-pm8008.c b/drivers/mfd/qcom-pm8008.c
index 569ffd50..55e2a8e 100644
--- a/drivers/mfd/qcom-pm8008.c
+++ b/drivers/mfd/qcom-pm8008.c
@@ -9,6 +9,7 @@
   #include <linux/interrupt.h>
   #include <linux/irq.h>
   #include <linux/irqdomain.h>
+#include <linux/mfd/qcom_pm8008.h>
   #include <linux/module.h>
   #include <linux/of_device.h>
   #include <linux/of_platform.h>
@@ -57,6 +58,7 @@ enum {
   struct pm8008_data {
       struct device *dev;
+    struct regmap *regulators_regmap;
       int irq;
       struct regmap_irq_chip_data *irq_data;
   };
@@ -150,6 +152,12 @@ static struct regmap_config qcom_mfd_regmap_cfg = {
       .max_register    = 0xFFFF,
   };
+struct regmap *pm8008_get_regmap(const struct pm8008_data *chip)
+{
+    return chip->regulators_regmap;
+}
+EXPORT_SYMBOL_GPL(pm8008_get_regmap);
Seems like abstraction for the sake of abstraction.

Why not do the dereference inside the regulator driver?
To derefer this in the regulator driver, we need to have the pm8008_data
struct definition in the qcom_pm8008 header file.

I think it doesn't look great to have only that structure in header and all
other structs and enum in the mfd driver.
Then why pass 'pm8008_data' at all?


There is one more option, instead of passing the pm8008_data, we could pass the pdev->dev.parent and get the pm8008 chip data directly in the pm8008_get_regmap() like below


struct regmap *pm8008_get_regmap(const struct device *dev)
 {
     const struct pm8008_data *chip = dev_get_drvdata(dev);

     return chip->regulators_regmap;
}
EXPORT_SYMBOL_GPL(pm8008_get_regmap);


By doing this we can avoid having declaration of pm8008_data also in the header. Please let me know if this looks good.


Could you please confirm on this?


What's preventing you from passing 'regmap'?


I didn't get what you meant here, could you please elaborate a bit?