From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 980AB1AF0D7; Wed, 19 Mar 2025 19:28:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742412492; cv=none; b=dZYniQ7MeEx6Sf5eECkwLaUc+mbJE/sjNyzBpWGdtAzaH+FTUl1+9zTi8fEWPixl9GNc4C0ls0lbYQzxA5lL3lSF/8Oy/18RG0uyR97cUB1cotRYmruPulrgVtfxD8hAuhutjOCg9pJBxlgw4eSTdWj6YP0KeqVjuJM+lRL0VuY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742412492; c=relaxed/simple; bh=xVpheGEMSdvufAyA000NnxguGemRFVyG24RA4OWDHBo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QNu9GdV9hApZlRwAOa9b7blhILDgznV55PhArXenxBJby1LAEo5LbaMwDkCGu8ByqvnWCp6lxK+YsMDqEUyNHr2rBVRoJrjzSP5Rm9sPqyWtj1BTeNC+dr1kd2WQA38vT8mq1B8dSUlf8eB2oYHnbJoP7f+EMgQR0Jr1ii69zzM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=b4nl5dZV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="b4nl5dZV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 919ABC4CEE4; Wed, 19 Mar 2025 19:28:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742412492; bh=xVpheGEMSdvufAyA000NnxguGemRFVyG24RA4OWDHBo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=b4nl5dZV887CaDJswTbT6ngspDFBwC65oJ8cHOO5Bc1ehoUoyaPBY/Y+m6OeMLaMa 9oqITyqpZs6oRMEZXT9ouL2YLzHyBt5h+EVAI+VKH9b1wIJhBSsg2+Vh7D34pJjRCM 95WcHcA2Esprmkb6UX2CdgCzR6kSnqgTaxg2cAjQEnh0uoB5ek50QOJfKLv/393TpE llqixryAVzFNrXF/B8OTSAUzVirPLjBN6SVQCGbbDO739igp7abfmbWZKjGHwfDmq/ wAbVNs7Ds8IyhMYr1C7pzoNzRrl4FpxpPzlU8GN/iSLN34DQzM8VIXGMFnbUkMYQ86 omZfYBLPVwo0Q== Message-ID: <92d8d240-5156-414f-b58b-a957e27eb30c@kernel.org> Date: Wed, 19 Mar 2025 20:28:06 +0100 Precedence: bulk X-Mailing-List: linux-leds@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/2] leds: tps6131x: add support for Texas Instruments TPS6131X flash LED driver To: Matthias Fend Cc: Pavel Machek , Lee Jones , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, bsp-development.geo@leica-geosystems.com References: <20250318-leds-tps6131x-v2-0-bc09c7a50b2e@emfend.at> <20250318-leds-tps6131x-v2-2-bc09c7a50b2e@emfend.at> <20250319-tall-ruddy-flamingo-a12fcc@krzk-bin> <9a470dfd-8d7b-4529-b54b-289754b9eed6@emfend.at> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJgPO8PBQkUX63hAAoJEBuTQ307 QWKbBn8P+QFxwl7pDsAKR1InemMAmuykCHl+XgC0LDqrsWhAH5TYeTVXGSyDsuZjHvj+FRP+ gZaEIYSw2Yf0e91U9HXo3RYhEwSmxUQ4Fjhc9qAwGKVPQf6YuQ5yy6pzI8brcKmHHOGrB3tP /MODPt81M1zpograAC2WTDzkICfHKj8LpXp45PylD99J9q0Y+gb04CG5/wXs+1hJy/dz0tYy iua4nCuSRbxnSHKBS5vvjosWWjWQXsRKd+zzXp6kfRHHpzJkhRwF6ArXi4XnQ+REnoTfM5Fk VmVmSQ3yFKKePEzoIriT1b2sXO0g5QXOAvFqB65LZjXG9jGJoVG6ZJrUV1MVK8vamKoVbUEe 0NlLl/tX96HLowHHoKhxEsbFzGzKiFLh7hyboTpy2whdonkDxpnv/H8wE9M3VW/fPgnL2nPe xaBLqyHxy9hA9JrZvxg3IQ61x7rtBWBUQPmEaK0azW+l3ysiNpBhISkZrsW3ZUdknWu87nh6 eTB7mR7xBcVxnomxWwJI4B0wuMwCPdgbV6YDUKCuSgRMUEiVry10xd9KLypR9Vfyn1AhROrq AubRPVeJBf9zR5UW1trJNfwVt3XmbHX50HCcHdEdCKiT9O+FiEcahIaWh9lihvO0ci0TtVGZ MCEtaCE80Q3Ma9RdHYB3uVF930jwquplFLNF+IBCn5JRzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmA872oFCRRflLYACgkQG5NDfTtBYpvScw/9GrqBrVLuJoJ52qBBKUBDo4E+5fU1bjt0 Gv0nh/hNJuecuRY6aemU6HOPNc2t8QHMSvwbSF+Vp9ZkOvrM36yUOufctoqON+wXrliEY0J4 ksR89ZILRRAold9Mh0YDqEJc1HmuxYLJ7lnbLYH1oui8bLbMBM8S2Uo9RKqV2GROLi44enVt vdrDvo+CxKj2K+d4cleCNiz5qbTxPUW/cgkwG0lJc4I4sso7l4XMDKn95c7JtNsuzqKvhEVS oic5by3fbUnuI0cemeizF4QdtX2uQxrP7RwHFBd+YUia7zCcz0//rv6FZmAxWZGy5arNl6Vm lQqNo7/Poh8WWfRS+xegBxc6hBXahpyUKphAKYkah+m+I0QToCfnGKnPqyYIMDEHCS/RfqA5 t8F+O56+oyLBAeWX7XcmyM6TGeVfb+OZVMJnZzK0s2VYAuI0Rl87FBFYgULdgqKV7R7WHzwD uZwJCLykjad45hsWcOGk3OcaAGQS6NDlfhM6O9aYNwGL6tGt/6BkRikNOs7VDEa4/HlbaSJo 7FgndGw1kWmkeL6oQh7wBvYll2buKod4qYntmNKEicoHGU+x91Gcan8mCoqhJkbqrL7+nXG2 5Q/GS5M9RFWS+nYyJh+c3OcfKqVcZQNANItt7+ULzdNJuhvTRRdC3g9hmCEuNSr+CLMdnRBY fv0= In-Reply-To: <9a470dfd-8d7b-4529-b54b-289754b9eed6@emfend.at> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 19/03/2025 17:25, Matthias Fend wrote: >>> + >>> + if (reg3 & TPS6131X_REG_3_HPFL) >>> + *fault |= LED_FAULT_SHORT_CIRCUIT; >>> + >>> + if (reg3 & TPS6131X_REG_3_SELSTIM_TO) >>> + *fault |= LED_FAULT_TIMEOUT; >>> + >>> + if (reg4 & TPS6131X_REG_4_HOTDIE_HI) >>> + *fault |= LED_FAULT_OVER_TEMPERATURE; >>> + >>> + if (reg6 & (TPS6131X_REG_6_LEDHOT | TPS6131X_REG_6_LEDWARN)) >>> + *fault |= LED_FAULT_LED_OVER_TEMPERATURE; >>> + >>> + if (!(reg6 & TPS6131X_REG_6_LEDHDR)) >>> + *fault |= LED_FAULT_UNDER_VOLTAGE; >>> + >>> + if (reg6 & TPS6131X_REG_6_LEDHOT) { >>> + ret = regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_6, >>> + TPS6131X_REG_6_LEDHOT, 0, NULL, false, true); >> >> And this is not locked? > > The read modify write operation is protected by regmap. Since this > operation does not interact with any other functions, no lock is needed > here. Following that logic no lock is needed in the first place. Define what is the purpose of this lock, not just "hardware access". I assumed you want to keep consistent hardware state between multiple updates. If that's correct, how did you prevent returning value from reads happening in the middle of concurrent update? Or how this update_bits_base is prevented from happening while you are in the middle of earlier calls which are protected by your lock? That's confusing lock, considering also too short comment explaining its purpose. > >> >>> + if (ret < 0) >>> + return ret; >>> + } >>> + >> >> ... >> >>> + >>> +static int tps6131x_flash_external_strobe_set(struct v4l2_flash *v4l2_flash, bool enable) >>> +{ >>> + struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev; >>> + struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev); >>> + >>> + guard(mutex)(&tps6131x->lock); >>> + >>> + return tps6131x_set_mode(tps6131x, enable ? TPS6131X_MODE_FLASH : TPS6131X_MODE_SHUTDOWN, >>> + false); >>> +} >>> + >>> +static const struct v4l2_flash_ops tps6131x_v4l2_flash_ops = { >>> + .external_strobe_set = tps6131x_flash_external_strobe_set, >>> +}; >>> + >>> +static int tps6131x_v4l2_setup(struct tps6131x *tps6131x) >>> +{ >>> + struct v4l2_flash_config v4l2_cfg = { 0 }; >>> + struct led_flash_setting *intensity = &v4l2_cfg.intensity; >>> + >>> + if (!IS_BUILTIN(CONFIG_V4L2_FLASH_LED_CLASS)) >> >> Why builtin? That's a tristate, so I don't get why driver and v4l flash >> cannot be modules. You wanted REACHABLE probably... but then it is >> anyway discouraged practice leading to runtime debugging. So actually >> you want CONFIG_V4L2_FLASH_LED_CLASS || !CONFIG_V4L2_FLASH_LED_CLASS >> dependency. > > Okay, I'll add 'depends on V4L2_FLASH_LED_CLASS || > !V4L2_FLASH_LED_CLASS' to the Kconfig entry and do the check in the > driver like this: Only this > if (!IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)) > return 0; > > Is this solution okay for you? This should should not be needed, because there are v4l2 stubs. Best regards, Krzysztof