[PATCH v2 2/2] clk: meson: axg-audio: add g12a reset support

From: Jerome Brunet
Date: Mon Aug 12 2019 - 08:33:07 EST


On the g12a, the register space dedicated to the audio clock also
provides some resets. Let the clock controller register a reset
provider as well for this SoC family.

the axg SoC family does not appear to provide this feature.

Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
drivers/clk/meson/axg-audio.c | 107 +++++++++++++++++++++++++++++++++-
drivers/clk/meson/axg-audio.h | 1 +
2 files changed, 106 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/meson/axg-audio.c b/drivers/clk/meson/axg-audio.c
index 741df7e955ca..6be9df1efce5 100644
--- a/drivers/clk/meson/axg-audio.c
+++ b/drivers/clk/meson/axg-audio.c
@@ -12,6 +12,7 @@
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>
+#include <linux/reset-controller.h>
#include <linux/slab.h>

#include "axg-audio.h"
@@ -918,6 +919,84 @@ static int devm_clk_get_enable(struct device *dev, char *id)
return 0;
}

+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 const struct regmap_config axg_audio_regmap_cfg = {
.reg_bits = 32,
.val_bits = 32,
@@ -927,12 +1006,15 @@ static const struct regmap_config axg_audio_regmap_cfg = {

struct audioclk_data {
struct clk_hw_onecell_data *hw_onecell_data;
+ unsigned int reset_offset;
+ unsigned int reset_num;
};

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 regmap *map;
struct resource *res;
void __iomem *regs;
@@ -984,8 +1066,27 @@ static int axg_audio_clkc_probe(struct platform_device *pdev)
}
}

- return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
- data->hw_onecell_data);
+ ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+ data->hw_onecell_data);
+ 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;
+
+ return devm_reset_controller_register(dev, &rst->rstc);
}

static const struct audioclk_data axg_audioclk_data = {
@@ -994,6 +1095,8 @@ static const struct audioclk_data axg_audioclk_data = {

static const struct audioclk_data g12a_audioclk_data = {
.hw_onecell_data = &g12a_audio_hw_onecell_data,
+ .reset_offset = AUDIO_SW_RESET,
+ .reset_num = 26,
};

static const struct of_device_id clkc_match_table[] = {
diff --git a/drivers/clk/meson/axg-audio.h b/drivers/clk/meson/axg-audio.h
index 5d972d55d6c7..c00e28b2e1a9 100644
--- a/drivers/clk/meson/axg-audio.h
+++ b/drivers/clk/meson/axg-audio.h
@@ -22,6 +22,7 @@
#define AUDIO_MCLK_F_CTRL 0x018
#define AUDIO_MST_PAD_CTRL0 0x01c
#define AUDIO_MST_PAD_CTRL1 0x020
+#define AUDIO_SW_RESET 0x024
#define AUDIO_MST_A_SCLK_CTRL0 0x040
#define AUDIO_MST_A_SCLK_CTRL1 0x044
#define AUDIO_MST_B_SCLK_CTRL0 0x048
--
2.21.0