diff mbox series

[v3,1/8] clk: renesas: Confirm all clock & reset changes on RZ/G2L

Message ID 20240227204035.3761-2-paul.barker.ct@bp.renesas.com
State Accepted
Commit aecd69879df8e7051281c1a2414ad33e75ff4ef4
Delegated to: Marek Vasut
Headers show
Series Add i2c and reset support for Renesas RZ/G2L | expand

Commit Message

Paul Barker Feb. 27, 2024, 8:40 p.m. UTC 
When enabling/disabling a clock or reset signal, confirm that the change
has completed before returning from the function. A somewhat arbitrary
100ms timeout is defined to ensure that the system doesn't lock up in
the case of an error.

Since we need to dynamically determine if we're waiting for a 0 bit or a
1 bit, it's easier to use wait_for_bit_32() than readl_poll_timeout().

This change is needed for reliable initialization of the I2C driver
which is added in a following patch.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
 drivers/clk/renesas/rzg2l-cpg.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c
index e54508c35ce2..dba009997a81 100644
--- a/drivers/clk/renesas/rzg2l-cpg.c
+++ b/drivers/clk/renesas/rzg2l-cpg.c
@@ -23,10 +23,18 @@ 
 #include <linux/iopoll.h>
 #include <reset-uclass.h>
 #include <reset.h>
+#include <wait_bit.h>
 
 #include "rzg2l-cpg.h"
 
+/*
+ * Monitor registers for both clock and reset signals are offset by 0x180 from
+ * the corresponding control registers.
+ */
 #define CLK_MON_R(reg)		(0x180 + (reg))
+#define RST_MON_R(reg)		(0x180 + (reg))
+
+#define CPG_TIMEOUT_MSEC	100
 
 static ulong rzg2l_cpg_clk_get_rate_by_id(struct udevice *dev, unsigned int id);
 static ulong rzg2l_cpg_clk_get_rate_by_name(struct udevice *dev, const char *name);
@@ -83,9 +91,9 @@  static int rzg2l_cpg_clk_set(struct clk *clk, bool enable)
 		value |= BIT(mod_clk->bit);
 	writel(value, data->base + mod_clk->off);
 
-	if (enable && readl_poll_timeout(data->base + CLK_MON_R(mod_clk->off),
-					 value, (value & BIT(mod_clk->bit)),
-					 10)) {
+	if (enable && wait_for_bit_32(data->base + CLK_MON_R(mod_clk->off),
+				      BIT(mod_clk->bit), enable,
+				      CPG_TIMEOUT_MSEC, false)) {
 		dev_err(clk->dev, "Timeout\n");
 		return -ETIMEDOUT;
 	}
@@ -420,7 +428,8 @@  static int rzg2l_cpg_rst_set(struct reset_ctl *reset_ctl, bool asserted)
 		value |= BIT(rst->bit);
 	writel(value, data->base + rst->off);
 
-	return 0;
+	return wait_for_bit_32(data->base + RST_MON_R(rst->off), BIT(rst->bit),
+			       asserted, CPG_TIMEOUT_MSEC, false);
 }
 
 static int rzg2l_cpg_rst_assert(struct reset_ctl *reset_ctl)