[PATCH v4 02/16] i3c: renesas: Restore STDBR and EXTBR registers on resume

[Claudiu Beznea]

From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>

The Renesas RZ/G3S supports a power saving state where power to the most
SoC componentes (including I3C) is lost.

The STDBR and EXTBR are configured in initialization phase though the
struct i3c_master_controller_ops::bus_init. Set them on resume function
as well to keep the same state of the controller after a suspend with
power loss and a similar initialization sequence as in bus_init.

Fixes: e7218986319b ("i3c: renesas: Add suspend/resume support")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
---

Changes in v4:
- none

Changes in v3:
- none

Changes in v2:
- collected tags

 drivers/i3c/master/renesas-i3c.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
index bc1a0ae1d12d..e70db3a17bc7 100644
--- a/drivers/i3c/master/renesas-i3c.c
+++ b/drivers/i3c/master/renesas-i3c.c
@@ -260,6 +260,7 @@ struct renesas_i3c {
 	u32 dyn_addr;
 	u32 i2c_STDBR;
 	u32 i3c_STDBR;
+	u32 extbr;
 	unsigned long rate;
 	u8 addrs[RENESAS_I3C_MAX_DEVS];
 	struct renesas_i3c_xferqueue xferqueue;
@@ -607,10 +608,9 @@ static int renesas_i3c_bus_init(struct i3c_master_controller *m)
 	renesas_writel(i3c->regs, STDBR, i3c->i3c_STDBR);
 
 	/* Extended Bit Rate setting */
-	renesas_writel(i3c->regs, EXTBR, EXTBR_EBRLO(od_low_ticks) |
-					   EXTBR_EBRHO(od_high_ticks) |
-					   EXTBR_EBRLP(pp_low_ticks) |
-					   EXTBR_EBRHP(pp_high_ticks));
+	i3c->extbr = EXTBR_EBRLO(od_low_ticks) | EXTBR_EBRHO(od_high_ticks) |
+		     EXTBR_EBRLP(pp_low_ticks) | EXTBR_EBRHP(pp_high_ticks);
+	renesas_writel(i3c->regs, EXTBR, i3c->extbr);
 
 	renesas_writel(i3c->regs, REFCKCTL, REFCKCTL_IREFCKS(cks));
 	i3c->refclk_div = cks;
@@ -1470,6 +1470,8 @@ static int renesas_i3c_resume_noirq(struct device *dev)
 		goto err_tresetn;
 
 	/* Re-store I3C registers value. */
+	renesas_writel(i3c->regs, STDBR, i3c->i3c_STDBR);
+	renesas_writel(i3c->regs, EXTBR, i3c->extbr);
 	renesas_writel(i3c->regs, REFCKCTL,
 		       REFCKCTL_IREFCKS(i3c->refclk_div));
 	renesas_writel(i3c->regs, MSDVAD, MSDVAD_MDYADV |
-- 
2.43.0