mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Rengarajan S <rengarajan.s@microchip.com>
To: <tharunkumar.pasumarthi@microchip.com>,
	<kumaravel.thiagarajan@microchip.com>,
	<UNGLinuxDriver@microchip.com>, <andi.shyti@kernel.org>,
	<linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <rengarajan.s@microchip.com>
Subject: [PATCH v1 i2c-master] i2c: mchp-pci1xxxx: Update minimum bus idle time
Date: Thu, 24 Jul 2025 09:34:22 +0530	[thread overview]
Message-ID: <20250724040422.6546-2-rengarajan.s@microchip.com> (raw)
In-Reply-To: <20250724040422.6546-1-rengarajan.s@microchip.com>

The SMBUS controller clock is designed with a 64 MHz clock for the
MCU, while the PCI1xxxx chip assumes a 31.25 MHz baud clock. SMBUS
controller register values are calculated considering 1 unit = 32 ns.
Based on this unit, the BUS_IDLE_MIN register values are updated for
all supported clock frequencies. Setting the MSB of BUS_IDLE_MIN[7:0]
register further scales the minimum bus idle time by a factor of 4.

Fixes: aa874cdfec07 ("i2c: mchp-pci1xxxx: Update Timing registers")
Signed-off-by: Rengarajan S <rengarajan.s@microchip.com>
---
 drivers/i2c/busses/i2c-mchp-pci1xxxx.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mchp-pci1xxxx.c b/drivers/i2c/busses/i2c-mchp-pci1xxxx.c
index 5ef136c3ecb1..cb9455b38c1d 100644
--- a/drivers/i2c/busses/i2c-mchp-pci1xxxx.c
+++ b/drivers/i2c/busses/i2c-mchp-pci1xxxx.c
@@ -190,9 +190,9 @@
  * Bus Idle Minimum time = BUS_IDLE_MIN[7:0] x Baud_Clock_Period x
  * (BUS_IDLE_MIN_XK_TICKS[7] ? 4,1)
  */
-#define BUS_IDLE_MIN_100K_TICKS		36UL
-#define BUS_IDLE_MIN_400K_TICKS		10UL
-#define BUS_IDLE_MIN_1000K_TICKS	4UL
+#define BUS_IDLE_MIN_100K_TICKS		165
+#define BUS_IDLE_MIN_400K_TICKS		40
+#define BUS_IDLE_MIN_1000K_TICKS	16
 
 /*
  * CTRL_CUM_TIME_OUT_XK_TICKS defines SMBus Controller Cumulative Time-Out.
-- 
2.25.1


      reply	other threads:[~2025-07-24  4:08 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-24  4:04 [PATCH v1 i2c-master] i2c: mchp-pci1xxxx: PCIe Hot reset disable support for Rev C0+ devices Rengarajan S
2025-07-24  4:04 ` Rengarajan S [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250724040422.6546-2-rengarajan.s@microchip.com \
    --to=rengarajan.s@microchip.com \
    --cc=UNGLinuxDriver@microchip.com \
    --cc=andi.shyti@kernel.org \
    --cc=kumaravel.thiagarajan@microchip.com \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tharunkumar.pasumarthi@microchip.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®