From 21cded44e69c630799e65baadb72ad123d1347c8 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 13 Jul 2026 16:05:30 +0300 Subject: [PATCH] i3c: renesas: Restore STDBR and EXTBR registers on resume 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@vger.kernel.org Reviewed-by: Frank Li Signed-off-by: Claudiu Beznea Tested-by: Tommaso Merciai Link: https://patch.msgid.link/20260713130545.568657-3-claudiu.beznea+renesas@tuxon.dev Signed-off-by: Alexandre Belloni --- 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 676ba863661f..acfc38b18896 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; @@ -622,10 +623,9 @@ 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; @@ -1476,6 +1476,8 @@ 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 |