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References: <20230411135558.44282-1-xingyu.wu@starfivetech.com> <20230411135558.44282-8-xingyu.wu@starfivetech.com> <683cbe934d1df9436e003466d2a419ef.sboyd@kernel.org> <463ee23c-f617-bed0-27a8-56c6fb40d092@starfivetech.com>
Subject: Re: [PATCH v4 07/10] clk: starfive: Add StarFive JH7110 Video-Output clock driver
From:   Stephen Boyd <sboyd@kernel.org>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Hal Feng <hal.feng@starfivetech.com>,
        linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org
To:     Conor Dooley <conor@kernel.org>,
        Emil Renner Berthing <kernel@esmil.dk>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Xingyu Wu <xingyu.wu@starfivetech.com>,
        devicetree@vger.kernel.org, linux-riscv@lists.infradead.org
Date:   Wed, 12 Apr 2023 21:04:08 -0700
User-Agent: alot/0.10
Precedence: bulk

Quoting Xingyu Wu (2023-04-11 23:15:26)
> On 2023/4/12 2:33, Stephen Boyd wrote:
> > Quoting Xingyu Wu (2023-04-11 06:55:55)
> >> diff --git a/drivers/clk/starfive/clk-starfive-jh7110-vout.c b/drivers=
/clk/starfive/clk-starfive-jh7110-vout.c
> >> new file mode 100644
> >> index 000000000000..4c6f5ae198cf
> >> --- /dev/null
> >> +++ b/drivers/clk/starfive/clk-starfive-jh7110-vout.c
> >> @@ -0,0 +1,239 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * StarFive JH7110 Video-Output Clock Driver
> >> + *
> >> + * Copyright (C) 2022 StarFive Technology Co., Ltd.
> >> + */
> >> +
> >> +#include <linux/clk.h>
> >> +#include <linux/clk-provider.h>
> >> +#include <linux/io.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/pm_runtime.h>
> >> +#include <linux/reset.h>
> >=20
> > Include module.h, device.h, and kernel.h for things like ERR_PTR().
>=20
> The local headfile 'clk-starfive-jh71x0.h' from the basic JH71x0 clock dr=
iver
> already includes the device.h.=20
> And I found the module.h is included in device/driver.h file and then it =
is included
> in the device.h file.
> The kernel.h is included in the clk.h file.
> So do I still need to list them?

Yes.

>=20
> > Probably need to include a reset header as well for reset APIs.
>=20
> The reset APIs like devm_reset_control_get_shared() and reset_control_dea=
ssert()
> come from the reset.h file and I have included it.

Cool, I missed it.

>=20
> >=20
> >> +
> >> +#include <dt-bindings/clock/starfive,jh7110-crg.h>
> >> +
> >> +#include "clk-starfive-jh7110.h"
> >> +
> >> +/* external clocks */
> >> +#define JH7110_VOUTCLK_VOUT_SRC                        (JH7110_VOUTCL=
K_END + 0)
> >> +#define JH7110_VOUTCLK_VOUT_TOP_AHB            (JH7110_VOUTCLK_END + =
1)
> >> +#define JH7110_VOUTCLK_VOUT_TOP_AXI            (JH7110_VOUTCLK_END + =
2)
> >> +#define JH7110_VOUTCLK_VOUT_TOP_HDMITX0_MCLK   (JH7110_VOUTCLK_END + =
3)
> >> +#define JH7110_VOUTCLK_I2STX0_BCLK             (JH7110_VOUTCLK_END + =
4)
> >> +#define JH7110_VOUTCLK_HDMITX0_PIXELCLK                (JH7110_VOUTCL=
K_END + 5)
> >> +#define JH7110_VOUTCLK_EXT_END                 (JH7110_VOUTCLK_END + =
6)
> >> +
> >> +/* VOUT domian clocks */
> >> +struct vout_top_crg {
> >> +       struct clk_bulk_data *top_clks;
> >> +       int top_clks_num;
> >=20
> > size_t?
>=20
> Will modify to 'unsigned int'.

Why not size_t?

>=20
> >=20
> >> +       if (ret < 0)
> >> +               return dev_err_probe(priv->dev, ret, "failed to turn o=
n power\n");
> >> +
> >> +       ret =3D jh7110_vout_top_crg_init(priv, top);
> >> +       if (ret)
> >> +               goto err_clk;
> >> +
> >> +       top->base =3D priv->base;
> >> +       dev_set_drvdata(priv->dev, (void *)(&top->base));
> >=20
> > See comment later about setting this to 'top' instead. Casting away
> > iomem markings is not good hygiene.
>=20
> JH7110 resets as the auxiliary device of clocks use the same iomem as the=
 clocks
> and the iomem will be got by dev_get_drvdata() in the 7110 reset drivers =
when registering reset.
> So I follow the basic 7110 reset driver and also set the iomem not top_cr=
g struct.

Oh I totally missed that this is how it's been done for the other
starfive driver. It's still not good hygiene to stash the iomem pointer
that way because the iomem marking is lost and has to be recovered. Can
you make a wrapper struct, either for the adev or to pass in struct
device::platform_data?

---8<---
diff --git a/drivers/clk/starfive/clk-starfive-jh7110-sys.c b/drivers/clk/s=
tarfive/clk-starfive-jh7110-sys.c
index 5ec210644e1d..851b93d0f371 100644
--- a/drivers/clk/starfive/clk-starfive-jh7110-sys.c
+++ b/drivers/clk/starfive/clk-starfive-jh7110-sys.c
@@ -11,6 +11,9 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <soc/starfive/reset-starfive-jh71x0.h>
=20
 #include <dt-bindings/clock/starfive,jh7110-crg.h>
=20
@@ -335,26 +338,32 @@ static void jh7110_reset_unregister_adev(void *_adev)
 	struct auxiliary_device *adev =3D _adev;
=20
 	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
 }
=20
 static void jh7110_reset_adev_release(struct device *dev)
 {
 	struct auxiliary_device *adev =3D to_auxiliary_dev(dev);
+	struct jh71x0_reset_adev *rdev =3D to_jh71x0_reset_adev(adev);
=20
-	auxiliary_device_uninit(adev);
+	kfree(rdev);
 }
=20
 int jh7110_reset_controller_register(struct jh71x0_clk_priv *priv,
 				     const char *adev_name,
 				     u32 adev_id)
 {
+	struct jh71x0_reset_adev *rdev;
 	struct auxiliary_device *adev;
 	int ret;
=20
-	adev =3D devm_kzalloc(priv->dev, sizeof(*adev), GFP_KERNEL);
-	if (!adev)
+	rdev =3D kzalloc(sizeof(*rdev), GFP_KERNEL);
+	if (!rdev)
 		return -ENOMEM;
=20
+	rdev->base =3D priv->base;
+
+	adev =3D &rdev->adev;
 	adev->name =3D adev_name;
 	adev->dev.parent =3D priv->dev;
 	adev->dev.release =3D jh7110_reset_adev_release;
diff --git a/drivers/reset/starfive/reset-starfive-jh7110.c b/drivers/reset=
/starfive/reset-starfive-jh7110.c
index c1b3a490d951..2d26ae95c8cc 100644
--- a/drivers/reset/starfive/reset-starfive-jh7110.c
+++ b/drivers/reset/starfive/reset-starfive-jh7110.c
@@ -7,6 +7,8 @@
=20
 #include <linux/auxiliary_bus.h>
=20
+#include <soc/starfive/reset-starfive-jh71x0.h>
+
 #include "reset-starfive-jh71x0.h"
=20
 #include <dt-bindings/reset/starfive,jh7110-crg.h>
@@ -33,14 +35,15 @@ static int jh7110_reset_probe(struct auxiliary_device *=
adev,
 			      const struct auxiliary_device_id *id)
 {
 	struct jh7110_reset_info *info =3D (struct jh7110_reset_info *)(id->drive=
r_data);
-	void __iomem **base =3D (void __iomem **)dev_get_drvdata(adev->dev.parent=
);
+	struct jh71x0_reset_adev *rdev =3D to_jh71x0_reset_adev(adev);
+	void __iomem *base =3D rdev->base;
=20
 	if (!info || !base)
 		return -ENODEV;
=20
 	return reset_starfive_jh71x0_register(&adev->dev, adev->dev.parent->of_no=
de,
-					      *base + info->assert_offset,
-					      *base + info->status_offset,
+					      base + info->assert_offset,
+					      base + info->status_offset,
 					      NULL,
 					      info->nr_resets,
 					      NULL);
diff --git a/include/soc/starfive/reset-starfive-jh71x0.h b/include/soc/sta=
rfive/reset-starfive-jh71x0.h
new file mode 100644
index 000000000000..47b486ececc5
--- /dev/null
+++ b/include/soc/starfive/reset-starfive-jh71x0.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __SOC_STARFIVE_RESET_JH71X0_H
+#define __SOC_STARFIVE_RESET_JH71X0_H
+
+#include <linux/auxiliary_bus.h>
+#include <linux/compiler_types.h>
+#include <linux/container_of.h>
+
+struct jh71x0_reset_adev {
+	void __iomem *base;
+	struct auxiliary_device adev;
+};
+
+#define to_jh71x0_reset_adev(_adev) \
+	container_of((_adev), struct jh71x0_reset_adev, adev)
+
+#endif
--=20
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git