[PATCH v3 7/7] clk: amlogic: axg-audio: use the auxiliary reset driver - take 2

Jerome Brunet
2025-02-11T17:28:42Z

Remove the implementation of the reset driver in axg audio
clock driver and migrate to the one provided by reset framework
on the auxiliary bus.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
There has been a discussion about the use on imply here.
After re-reading the documentation I've sticked with imply in this
version:

> This is useful e.g. with multiple drivers that want to indicate their
> ability to hook into a secondary subsystem while allowing the user to
> configure that subsystem out without also having to unset these drivers.

IMO, this is a pretty accurate description of the use case in this change.

The pitfall mentioned in the doc does not apply as there is not link error
regardless of the config of RESET_MESON_AUX.

I also think this is more readeable and maintainable than a bunch of
'default CONFIG_FOO if CONFIG_FOO' for CONFIG_RESET_MESON_AUX. This approach
also would have several pitfall, such as picking the value of the first config
set or the config of RESET_MESON_AUX staying to 'n' if CONFIG_FOO is turned on
with menuconfig.

drivers/clk/meson/Kconfig | 2 +-
drivers/clk/meson/axg-audio.c | 114 +++++-------------------------------------
2 files changed, 14 insertions(+), 102 deletions(-)

diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
index be2e3a5f83363b07cdcec2601acf15780ff24892..7cb21fc223b063cb93812643f02f192343981ed8 100644
--- a/drivers/clk/meson/Kconfig
+++ b/drivers/clk/meson/Kconfig
@@ -106,7 +106,7 @@ config COMMON_CLK_AXG_AUDIO
select COMMON_CLK_MESON_SCLK_DIV
select COMMON_CLK_MESON_CLKC_UTILS
select REGMAP_MMIO
- select RESET_CONTROLLER
+ imply RESET_MESON_AUX
help
Support for the audio clock controller on AmLogic A113D devices,
aka axg, Say Y if you want audio subsystem to work.
diff --git a/drivers/clk/meson/axg-audio.c b/drivers/clk/meson/axg-audio.c
index 9df627b142f89788966ede0262aaaf39e13f0b49..6d798705c5fd1e6190192294783c955fc9be1e21 100644
--- a/drivers/clk/meson/axg-audio.c
+++ b/drivers/clk/meson/axg-audio.c
@@ -4,6 +4,7 @@
* Author: Jerome Brunet <jbrunet@baylibre.com>
*/

+#include <linux/auxiliary_bus.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/init.h>
@@ -12,7 +13,6 @@
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>
-#include <linux/reset-controller.h>
#include <linux/slab.h>

#include "meson-clkc-utils.h"
@@ -1678,84 +1678,6 @@ static struct clk_regmap *const sm1_clk_regmaps[] = {
&sm1_earcrx_dmac_clk,
};

-struct axg_audio_reset_data {
- struct reset_controller_dev rstc;
- struct regmap *map;
- unsigned int offset;
-};
-
-static void axg_audio_reset_reg_and_bit(struct axg_audio_reset_data *rst,
- unsigned long id,
- unsigned int *reg,
- unsigned int *bit)
-{
- unsigned int stride = regmap_get_reg_stride(rst->map);
-
- *reg = (id / (stride * BITS_PER_BYTE)) * stride;
- *reg += rst->offset;
- *bit = id % (stride * BITS_PER_BYTE);
-}
-
-static int axg_audio_reset_update(struct reset_controller_dev *rcdev,
- unsigned long id, bool assert)
-{
- struct axg_audio_reset_data *rst =
- container_of(rcdev, struct axg_audio_reset_data, rstc);
- unsigned int offset, bit;
-
- axg_audio_reset_reg_and_bit(rst, id, &offset, &bit);
-
- regmap_update_bits(rst->map, offset, BIT(bit),
- assert ? BIT(bit) : 0);
-
- return 0;
-}
-
-static int axg_audio_reset_status(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- struct axg_audio_reset_data *rst =
- container_of(rcdev, struct axg_audio_reset_data, rstc);
- unsigned int val, offset, bit;
-
- axg_audio_reset_reg_and_bit(rst, id, &offset, &bit);
-
- regmap_read(rst->map, offset, &val);
-
- return !!(val & BIT(bit));
-}
-
-static int axg_audio_reset_assert(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- return axg_audio_reset_update(rcdev, id, true);
-}
-
-static int axg_audio_reset_deassert(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- return axg_audio_reset_update(rcdev, id, false);
-}
-
-static int axg_audio_reset_toggle(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- int ret;
-
- ret = axg_audio_reset_assert(rcdev, id);
- if (ret)
- return ret;
-
- return axg_audio_reset_deassert(rcdev, id);
-}
-
-static const struct reset_control_ops axg_audio_rstc_ops = {
- .assert = axg_audio_reset_assert,
- .deassert = axg_audio_reset_deassert,
- .reset = axg_audio_reset_toggle,
- .status = axg_audio_reset_status,
-};
-
static struct regmap_config axg_audio_regmap_cfg = {
.reg_bits = 32,
.val_bits = 32,
@@ -1766,8 +1688,7 @@ struct audioclk_data {
struct clk_regmap *const *regmap_clks;
unsigned int regmap_clk_num;
struct meson_clk_hw_data hw_clks;
- unsigned int reset_offset;
- unsigned int reset_num;
+ const char *rst_drvname;
unsigned int max_register;
};

@@ -1775,7 +1696,7 @@ static int axg_audio_clkc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct audioclk_data *data;
- struct axg_audio_reset_data *rst;
+ struct auxiliary_device *auxdev;
struct regmap *map;
void __iomem *regs;
struct clk_hw *hw;
@@ -1834,22 +1755,15 @@ static int axg_audio_clkc_probe(struct platform_device *pdev)
if (ret)
return ret;

- /* Stop here if there is no reset */
- if (!data->reset_num)
- return 0;
-
- rst = devm_kzalloc(dev, sizeof(*rst), GFP_KERNEL);
- if (!rst)
- return -ENOMEM;
-
- rst->map = map;
- rst->offset = data->reset_offset;
- rst->rstc.nr_resets = data->reset_num;
- rst->rstc.ops = &axg_audio_rstc_ops;
- rst->rstc.of_node = dev->of_node;
- rst->rstc.owner = THIS_MODULE;
+ /* Register auxiliary reset driver when applicable */
+ if (data->rst_drvname) {
+ auxdev = __devm_auxiliary_device_create(dev, dev->driver->name,
+ data->rst_drvname, NULL, 0);
+ if (IS_ERR(auxdev))
+ return PTR_ERR(auxdev);
+ }

- return devm_reset_controller_register(dev, &rst->rstc);
+ return 0;
}

static const struct audioclk_data axg_audioclk_data = {
@@ -1869,8 +1783,7 @@ static const struct audioclk_data g12a_audioclk_data = {
.hws = g12a_audio_hw_clks,
.num = ARRAY_SIZE(g12a_audio_hw_clks),
},
- .reset_offset = AUDIO_SW_RESET,
- .reset_num = 26,
+ .rst_drvname = "rst-g12a",
.max_register = AUDIO_CLK_SPDIFOUT_B_CTRL,
};

@@ -1881,8 +1794,7 @@ static const struct audioclk_data sm1_audioclk_data = {
.hws = sm1_audio_hw_clks,
.num = ARRAY_SIZE(sm1_audio_hw_clks),
},
- .reset_offset = AUDIO_SM1_SW_RESET0,
- .reset_num = 39,
+ .rst_drvname = "rst-sm1",
.max_register = AUDIO_EARCRX_DMAC_CLK_CTRL,
};

--
2.45.2