When system suspends, if i3c module is powered down, register
value will lose.
Need to save the key registers before system suspend.
So save these registers value in runtime pm suspend, and restore them
if these register's value is different with the saved values
when runtime pm resume.
Signed-off-by: Clark Wang <[email protected]>
---
drivers/i3c/master/svc-i3c-master.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index e3f454123805..bca3a4352ad1 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -145,6 +145,11 @@ struct svc_i3c_xfer {
struct svc_i3c_cmd cmds[];
};
+struct svc_i3c_regs_save {
+ u32 mconfig;
+ u32 mdynaddr;
+};
+
/**
* struct svc_i3c_master - Silvaco I3C Master structure
* @base: I3C master controller
@@ -173,6 +178,7 @@ struct svc_i3c_master {
struct i3c_master_controller base;
struct device *dev;
void __iomem *regs;
+ struct svc_i3c_regs_save saved_regs;
u32 free_slots;
u8 addrs[SVC_I3C_MAX_DEVS];
struct i3c_dev_desc *descs[SVC_I3C_MAX_DEVS];
@@ -1579,10 +1585,28 @@ static void svc_i3c_master_remove(struct platform_device *pdev)
pm_runtime_disable(&pdev->dev);
}
+static void svc_i3c_save_regs(struct svc_i3c_master *master)
+{
+ master->saved_regs.mconfig = readl(master->regs + SVC_I3C_MCONFIG);
+ master->saved_regs.mdynaddr = readl(master->regs + SVC_I3C_MDYNADDR);
+}
+
+static void svc_i3c_restore_regs(struct svc_i3c_master *master)
+{
+ if (readl(master->regs + SVC_I3C_MDYNADDR) !=
+ master->saved_regs.mdynaddr) {
+ writel(master->saved_regs.mconfig,
+ master->regs + SVC_I3C_MCONFIG);
+ writel(master->saved_regs.mdynaddr,
+ master->regs + SVC_I3C_MDYNADDR);
+ }
+}
+
static int __maybe_unused svc_i3c_runtime_suspend(struct device *dev)
{
struct svc_i3c_master *master = dev_get_drvdata(dev);
+ svc_i3c_save_regs(master);
svc_i3c_master_unprepare_clks(master);
pinctrl_pm_select_sleep_state(dev);
@@ -1596,6 +1620,8 @@ static int __maybe_unused svc_i3c_runtime_resume(struct device *dev)
pinctrl_pm_select_default_state(dev);
svc_i3c_master_prepare_clks(master);
+ svc_i3c_restore_regs(master);
+
return 0;
}
--
2.34.1
Add NACK check after start byte is sent.
It is possible to detect early that a device is not on the bus
and avoid invalid transmissions thereafter.
Signed-off-by: Clark Wang <[email protected]>
---
drivers/i3c/master/svc-i3c-master.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 4edf33ed207d..0d63b732ef0c 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -92,6 +92,7 @@
#define SVC_I3C_MINTCLR 0x094
#define SVC_I3C_MINTMASKED 0x098
#define SVC_I3C_MERRWARN 0x09C
+#define SVC_I3C_MERRWARN_NACK BIT(2)
#define SVC_I3C_MDMACTRL 0x0A0
#define SVC_I3C_MDATACTRL 0x0AC
#define SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
@@ -1014,6 +1015,11 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
if (ret)
goto emit_stop;
+ if (readl(master->regs + SVC_I3C_MERRWARN) & SVC_I3C_MERRWARN_NACK) {
+ ret = -ENXIO;
+ goto emit_stop;
+ }
+
if (rnw)
ret = svc_i3c_master_read(master, in, xfer_len);
else
--
2.34.1
Hi Clark,
[email protected] wrote on Wed, 17 May 2023 11:30:28 +0800:
> When system suspends, if i3c module is powered down, register
> value will lose.
> Need to save the key registers before system suspend.
> So save these registers value in runtime pm suspend, and restore them
> if these register's value is different with the saved values
> when runtime pm resume.
>
> Signed-off-by: Clark Wang <[email protected]>
Reviewed-by: Miquel Raynal <[email protected]>
Thanks,
Miquèl
Hi Clark,
[email protected] wrote on Wed, 17 May 2023 11:30:30 +0800:
> Add NACK check after start byte is sent.
> It is possible to detect early that a device is not on the bus
> and avoid invalid transmissions thereafter.
>
> Signed-off-by: Clark Wang <[email protected]>
Nice addition.
Reviewed-by: Miquel Raynal <[email protected]>
> ---
> drivers/i3c/master/svc-i3c-master.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 4edf33ed207d..0d63b732ef0c 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -92,6 +92,7 @@
> #define SVC_I3C_MINTCLR 0x094
> #define SVC_I3C_MINTMASKED 0x098
> #define SVC_I3C_MERRWARN 0x09C
> +#define SVC_I3C_MERRWARN_NACK BIT(2)
> #define SVC_I3C_MDMACTRL 0x0A0
> #define SVC_I3C_MDATACTRL 0x0AC
> #define SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
> @@ -1014,6 +1015,11 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
> if (ret)
> goto emit_stop;
>
> + if (readl(master->regs + SVC_I3C_MERRWARN) & SVC_I3C_MERRWARN_NACK) {
> + ret = -ENXIO;
> + goto emit_stop;
> + }
> +
> if (rnw)
> ret = svc_i3c_master_read(master, in, xfer_len);
> else
Thanks,
Miquèl
On Wed, 17 May 2023 11:30:28 +0800, Clark Wang wrote:
> When system suspends, if i3c module is powered down, register
> value will lose.
> Need to save the key registers before system suspend.
> So save these registers value in runtime pm suspend, and restore them
> if these register's value is different with the saved values
> when runtime pm resume.
>
> [...]
Applied, thanks!
[1/1] i3c: master: svc: fix i3c suspend/resume issue
commit: 1c5ee2a77b1bacd4c333bebea93610aaf17977be
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com