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From: Alexander Dahl <ada@thorsis.com>
To: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Cc: Christian Melki <christian.melki@t2data.com>,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
	linux-arm-kernel@lists.infradead.org (moderated list:MICROCHIP
	OTPC DRIVER), linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v1 01/12] nvmem: microchip-otpc: Avoid writing a write-only register
Date: Wed, 21 Aug 2024 12:59:32 +0200	[thread overview]
Message-ID: <20240821105943.230281-2-ada@thorsis.com> (raw)
In-Reply-To: <20240821105943.230281-1-ada@thorsis.com>

The OTPC Control Register (OTPC_CR) has just write-only members.
Reading from that register leads to a warning in OTPC Write Protection
Status Register (OTPC_WPSR) in field Software Error Type (SWETYP) of
type READ_WO (A write-only register has been read (warning).)

Just create the register write content from scratch is sufficient here.

Signed-off-by: Alexander Dahl <ada@thorsis.com>
---
 drivers/nvmem/microchip-otpc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvmem/microchip-otpc.c b/drivers/nvmem/microchip-otpc.c
index 7cf81738a3e0..03e60b99f2c9 100644
--- a/drivers/nvmem/microchip-otpc.c
+++ b/drivers/nvmem/microchip-otpc.c
@@ -82,7 +82,7 @@ static int mchp_otpc_prepare_read(struct mchp_otpc *otpc,
 	writel_relaxed(tmp, otpc->base + MCHP_OTPC_MR);
 
 	/* Set read. */
-	tmp = readl_relaxed(otpc->base + MCHP_OTPC_CR);
+	tmp = 0;
 	tmp |= MCHP_OTPC_CR_READ;
 	writel_relaxed(tmp, otpc->base + MCHP_OTPC_CR);
 
-- 
2.39.2


  reply	other threads:[~2024-08-21 10:59 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-21 10:59 [PATCH v1 00/12] Microchip OTPC driver on SAM9X60 exposing UIDxR as additional nvmem device Alexander Dahl
2024-08-21 10:59 ` Alexander Dahl [this message]
2024-08-24 15:51   ` [PATCH v1 01/12] nvmem: microchip-otpc: Avoid writing a write-only register claudiu beznea
2024-08-21 10:59 ` [PATCH v1 02/12] nvmem: microchip-otpc: Fix swapped 'sleep' and 'timeout' parameters Alexander Dahl
2024-08-24 15:52   ` claudiu beznea
2024-08-21 10:59 ` [PATCH v1 03/12] dt-bindings: nvmem: microchip-otpc: Add compatible for SAM9X60 Alexander Dahl
2024-08-21 12:49   ` Rob Herring (Arm)
2024-08-21 14:55   ` Conor Dooley
2024-08-21 10:59 ` [PATCH v1 04/12] nvmem: microchip-otpc: Add SAM9X60 support Alexander Dahl
2024-08-24 15:53   ` claudiu beznea
2024-08-28  8:09     ` Alexander Dahl
2024-08-31 15:31       ` claudiu beznea
2024-08-21 10:59 ` [PATCH v1 05/12] ARM: dts: microchip: sam9x60: Add OTPC node Alexander Dahl
2024-08-24 15:56   ` claudiu beznea
2024-08-21 10:59 ` [PATCH v1 06/12] ARM: dts: microchip: sam9x60_curiosity: Enable OTP Controller Alexander Dahl
2024-08-21 10:59 ` [PATCH v1 07/12] nvmem: microchip-otpc: Add missing register definitions Alexander Dahl
2024-08-24 15:54   ` claudiu beznea
2024-08-28  8:14     ` Alexander Dahl
2024-08-31 15:33       ` claudiu beznea
2024-09-02  8:08         ` Alexander Dahl
2024-09-07 12:05           ` claudiu beznea
2024-08-21 10:59 ` [PATCH v1 08/12] nvmem: microchip-otpc: Add warnings for bad OTPC conditions on probe Alexander Dahl
2024-08-24 15:51   ` claudiu beznea
2024-08-21 10:59 ` [PATCH v1 09/12] clk: at91: sam9x60: Allow enabling main_rc_osc through DT Alexander Dahl
2024-08-21 15:55   ` Conor Dooley
2024-09-19 12:39   ` Alexander Dahl
2024-09-24 15:52     ` Ryan Wanner
2024-09-25 15:24       ` Nicolas Ferre
2024-09-26  7:42       ` claudiu beznea
2024-10-01 15:04         ` Ryan Wanner
2025-02-07 12:41           ` Alexander Dahl
2024-08-21 10:59 ` [PATCH v1 10/12] ARM: dts: microchip: sam9x60: Add clock properties to OTPC Alexander Dahl
2024-08-24 15:57   ` claudiu beznea
2024-08-28  8:22     ` Alexander Dahl
2024-08-21 10:59 ` [PATCH v1 11/12] nvmem: microchip-otpc: Enable main RC oscillator clock Alexander Dahl
2024-08-22 15:57   ` kernel test robot
2024-08-24 15:53   ` claudiu beznea
2024-08-21 10:59 ` [PATCH v1 12/12] nvmem: microchip-otpc: Expose UID registers as 2nd nvmem device Alexander Dahl
2024-08-24 15:50   ` claudiu beznea
2024-08-24 16:17 ` [PATCH v1 00/12] Microchip OTPC driver on SAM9X60 exposing UIDxR as additional " claudiu beznea
2024-08-28  7:31   ` Alexander Dahl
2024-08-31 15:38     ` claudiu beznea

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