2023-04-13 10:50:31

by Trevor Wu (吳文良)

[permalink] [raw]
Subject: [PATCH 6/7] ASoC: mediatek: mt8188: add bus protection

Add bus protection for reset controller.

Signed-off-by: Trevor Wu <[email protected]>
---
sound/soc/mediatek/mt8188/mt8188-afe-pcm.c | 76 ++++++++++++++++++++++
1 file changed, 76 insertions(+)

diff --git a/sound/soc/mediatek/mt8188/mt8188-afe-pcm.c b/sound/soc/mediatek/mt8188/mt8188-afe-pcm.c
index fecc891f892d..c3fd32764da0 100644
--- a/sound/soc/mediatek/mt8188/mt8188-afe-pcm.c
+++ b/sound/soc/mediatek/mt8188/mt8188-afe-pcm.c
@@ -17,6 +17,7 @@
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
+#include <linux/soc/mediatek/infracfg.h>
#include <linux/reset.h>
#include <sound/pcm_params.h>
#include "mt8188-afe-common.h"
@@ -3133,12 +3134,68 @@ static int mt8188_afe_parse_of(struct mtk_base_afe *afe,
return 0;
}

+#define MT8188_DELAY_US 10
+#define MT8188_TIMEOUT_US USEC_PER_SEC
+
+static int bus_protect_enable(struct regmap *regmap)
+{
+ int ret;
+ u32 val;
+ u32 mask;
+
+ val = 0;
+ mask = MT8188_TOP_AXI_PROT_EN_2_AUDIO_STEP1;
+ regmap_write(regmap, MT8188_TOP_AXI_PROT_EN_2_SET, mask);
+
+ ret = regmap_read_poll_timeout(regmap, MT8188_TOP_AXI_PROT_EN_2_STA,
+ val, (val & mask) == mask,
+ MT8188_DELAY_US, MT8188_TIMEOUT_US);
+ if (ret)
+ return ret;
+
+ val = 0;
+ mask = MT8188_TOP_AXI_PROT_EN_2_AUDIO_STEP2;
+ regmap_write(regmap, MT8188_TOP_AXI_PROT_EN_2_SET, mask);
+
+ ret = regmap_read_poll_timeout(regmap, MT8188_TOP_AXI_PROT_EN_2_STA,
+ val, (val & mask) == mask,
+ MT8188_DELAY_US, MT8188_TIMEOUT_US);
+ return ret;
+}
+
+static int bus_protect_disable(struct regmap *regmap)
+{
+ int ret;
+ u32 val;
+ u32 mask;
+
+ val = 0;
+ mask = MT8188_TOP_AXI_PROT_EN_2_AUDIO_STEP2;
+ regmap_write(regmap, MT8188_TOP_AXI_PROT_EN_2_CLR, mask);
+
+ ret = regmap_read_poll_timeout(regmap, MT8188_TOP_AXI_PROT_EN_2_STA,
+ val, !(val & mask),
+ MT8188_DELAY_US, MT8188_TIMEOUT_US);
+ if (ret)
+ return ret;
+
+ val = 0;
+ mask = MT8188_TOP_AXI_PROT_EN_2_AUDIO_STEP1;
+ regmap_write(regmap, MT8188_TOP_AXI_PROT_EN_2_CLR, mask);
+
+ ret = regmap_read_poll_timeout(regmap, MT8188_TOP_AXI_PROT_EN_2_STA,
+ val, !(val & mask),
+ MT8188_DELAY_US, MT8188_TIMEOUT_US);
+ return ret;
+}
+
static int mt8188_afe_pcm_dev_probe(struct platform_device *pdev)
{
struct mtk_base_afe *afe;
struct mt8188_afe_private *afe_priv;
struct device *dev;
struct reset_control *rstc;
+ struct regmap *infra_ao;
int i, irq_id, ret;

ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(33));
@@ -3163,18 +3220,37 @@ static int mt8188_afe_pcm_dev_probe(struct platform_device *pdev)
return dev_err_probe(dev, PTR_ERR(afe->base_addr),
"AFE base_addr not found\n");

+ infra_ao = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "mediatek,infracfg");
+ if (IS_ERR(infra_ao))
+ return dev_err_probe(dev, PTR_ERR(infra_ao),
+ "%s() Cannot find infra_ao controller\n",
+ __func__);
+
/* reset controller to reset audio regs before regmap cache */
rstc = devm_reset_control_get_exclusive(dev, "audiosys");
if (IS_ERR(rstc))
return dev_err_probe(dev, PTR_ERR(rstc),
"could not get audiosys reset\n");

+ ret = bus_protect_enable(infra_ao);
+ if (ret) {
+ dev_err(dev, "bus_protect_enable failed\n");
+ return ret;
+ }
+
ret = reset_control_reset(rstc);
if (ret) {
dev_err(dev, "failed to trigger audio reset:%d\n", ret);
return ret;
}

+ ret = bus_protect_disable(infra_ao);
+ if (ret) {
+ dev_err(dev, "bus_protect_disable failed\n");
+ return ret;
+ }
+
/* initial audio related clock */
ret = mt8188_afe_init_clock(afe);
if (ret)
--
2.18.0


Subject: Re: [PATCH 6/7] ASoC: mediatek: mt8188: add bus protection

Il 13/04/23 12:47, Trevor Wu ha scritto:
> Add bus protection for reset controller.
>
> Signed-off-by: Trevor Wu <[email protected]>

Is MT8188 the only SoC that will ever use bus protection for reset, now and
in the future?

...otherwise, I think that the best solution here would be to implement that
into the reset controller itself.

Regards,
Angelo

2023-04-20 06:53:42

by Trevor Wu (吳文良)

[permalink] [raw]
Subject: Re: [PATCH 6/7] ASoC: mediatek: mt8188: add bus protection

On Thu, 2023-04-13 at 15:19 +0200, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>
>
> Il 13/04/23 12:47, Trevor Wu ha scritto:
> > Add bus protection for reset controller.
> >
> > Signed-off-by: Trevor Wu <[email protected]>
>
> Is MT8188 the only SoC that will ever use bus protection for reset,
> now and
> in the future?
>
> ...otherwise, I think that the best solution here would be to
> implement that
> into the reset controller itself.
>
> Regards,
> Angelo

Hi Angelo,

MT8188 is not the only SoC that will use bus protection for reset.
I checked with the owner of reset controller.
There are some reasons that they prefer to control bus protection by
each module which needs reset function individually. First, reset
function is only used by few modules. Second, bus protection register
for the same module is possibly different in each of SoCs. Finally, bus
protect bits are diverse, so it's not easy to implement in reset
controller driver.

Thanks,
Trevor