From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from chaosmail.tech (chaosmail.tech [77.81.229.115]) (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 B36D437D132; Fri, 12 Jun 2026 18:36:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=77.81.229.115 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781289377; cv=none; b=aBmzULDWzPLEdvTk+TUw2Sebje82zDrA8bOqL3GqyJN0TyVqW1+0Cp4a6F/YmB1DwbtSekC2e3VXe7Y/ftSnUXsXa/GtKMvyDOht2VAH8wUcCm8k6vRU+GI06306oniQdqURaaaahdqLf/a19c/FNlqNwz+XeHl3gBmz0He7U6s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781289377; c=relaxed/simple; bh=4A/C+EOHO465w2u8xamdqNmkNqrHgUkGdvhtrLwE2lg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=BWO5VVjLg2lQdSxuwRcwvuKA4NlglaYgTQTAxt8cKJVjjhJBYfxYud6jiTb0VxatlLipSJyJrPjFPlccQokfUFbcPoAHWeao6xjUDfjgsxxGnar4KxMcqu9ub1woFoyBftc73moJzCZ7L6juxeZ28Sn6MrpDVbX61tmoVNL4ESE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=chaosmail.tech; spf=pass smtp.mailfrom=chaosmail.tech; dkim=pass (1024-bit key) header.d=chaosmail.tech header.i=@chaosmail.tech header.b=cLzecYpO; arc=none smtp.client-ip=77.81.229.115 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=chaosmail.tech Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chaosmail.tech Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chaosmail.tech header.i=@chaosmail.tech header.b="cLzecYpO" Received: by chaosmail.tech (Postfix) id D91181C962C; Fri, 12 Jun 2026 18:36:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chaosmail.tech; s=mail; t=1781289367; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=UsS4dqSrxqQyi+VfVrN7/Fkk7cMDG+DRbrc2q63ns0c=; b=cLzecYpO3379MUQW5o4pE5ay4aiiwjREr51eLEUYK5B9Fjqj/B8pT253oF/WYXImOw608/ c/2u9eUo3N4l4n7ubKhjj2JaAuoVXFEOdtfo6lskWibWlFFuTB1Lu3K4LbgrTa1aWEbD/G 1RjTTtWduTKCFzYnhIBgh7oX8e0uaNk= From: Sasha Finkelstein Date: Fri, 12 Jun 2026 20:36:03 +0200 Subject: [PATCH v2] power: supply: macsmc: Support macOS 27 SMC firmware Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260612-gate-power-v2-1-de76cb9bb7ef@chaosmail.tech> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/22OQQ7CIBREr9L8tRhgAY0r72G6QPgt32hpAFHT9 O5C3bp8ycybWSFhJExw6laIWChRmCvIQwfWm3lCRq4ySC4VV0KwyWRkS3hhZHZ0WipnudMj1MI ScaT3LrsMP07P6w1tboaW8JRyiJ99rYiW+ysuggnWGyW1FLxXVp/rl5Aehu7HjNbDsG3bF3Ss9 4O7AAAA X-Change-ID: 20260611-gate-power-cfd726dc0d7f To: Sven Peter , Janne Grunau , Neal Gompa , Sebastian Reichel Cc: asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Sasha Finkelstein X-Developer-Signature: v=1; a=ed25519-sha256; t=1781289366; l=4184; i=k@chaosmail.tech; s=20241124; h=from:subject:message-id; bh=4A/C+EOHO465w2u8xamdqNmkNqrHgUkGdvhtrLwE2lg=; b=zoMPXpuIXjYSJqYFvYM9W4fKfd3tt2rqG5nEEW941D4Q6fM6tY3egLexCairjGf7a9qLa561Q Av/sJno8GlRDap+GJsoD0s/1O+VMCwdXvjt3giaYCF88YDj7S4MQbQl X-Developer-Key: i=k@chaosmail.tech; a=ed25519; pk=aSkp1PdZ+eF4jpMO6oLvz/YfT5XkBUneWwyhQrOgmsU= The SMC firmware included in macOS 27 changed the size of BCF0 key from 4 to 1 bytes. This key is used for indicating that battery state is critically low. Reviewed-by: Sven Peter Signed-off-by: Sasha Finkelstein --- Changes in v2: - Addressing review feedback - Link to v1: https://patch.msgid.link/20260611-gate-power-v1-1-8a62721086c7@chaosmail.tech --- drivers/power/supply/macsmc-power.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/drivers/power/supply/macsmc-power.c b/drivers/power/supply/macsmc-power.c index 33ca07460f3a..747315e372bc 100644 --- a/drivers/power/supply/macsmc-power.c +++ b/drivers/power/supply/macsmc-power.c @@ -86,6 +86,7 @@ struct macsmc_power { bool has_ch0i; /* Force discharge (Older firmware) */ bool has_ch0c; /* Inhibit charge (Older firmware) */ bool has_chte; /* Inhibit charge (Modern firmware) */ + bool bcf0_1byte; /* Battery critical key is 1 byte (Modern firmware) */ u8 num_cells; int nominal_voltage_mv; @@ -273,6 +274,19 @@ static int macsmc_battery_get_date(const char *s, int *out) return 0; } +static int macsmc_battery_read_bcf0(struct macsmc_power *power, u32 *val) +{ + u8 tval = 0; + int ret; + + if (!power->bcf0_1byte) + return apple_smc_read_u32(power->smc, SMC_KEY(BCF0), val); + + ret = apple_smc_read_u8(power->smc, SMC_KEY(BCF0), &tval); + *val = tval; + return ret; +} + static int macsmc_battery_get_capacity_level(struct macsmc_power *power) { bool flag; @@ -280,7 +294,7 @@ static int macsmc_battery_get_capacity_level(struct macsmc_power *power) int ret; /* Check for emergency shutdown condition */ - if (apple_smc_read_u32(power->smc, SMC_KEY(BCF0), &val) >= 0 && val) + if (macsmc_battery_read_bcf0(power, &val) >= 0 && val) return POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL; /* Check AC status for whether we could boot in this state */ @@ -577,7 +591,7 @@ static void macsmc_power_critical_work(struct work_struct *wrk) * Check if SMC flagged the battery as empty. * We trigger a graceful shutdown to let the OS save data. */ - if (apple_smc_read_u32(power->smc, SMC_KEY(BCF0), &bcf0) == 0 && bcf0 != 0) { + if (macsmc_battery_read_bcf0(power, &bcf0) == 0 && bcf0 != 0) { power->orderly_shutdown_triggered = true; dev_crit(power->dev, "Battery critical (empty flag set). Triggering orderly shutdown.\n"); orderly_poweroff(true); @@ -616,6 +630,7 @@ static int macsmc_power_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent); struct power_supply_config psy_cfg = {}; + struct apple_smc_key_info info; struct macsmc_power *power; bool has_battery = false; bool has_ac_adapter = false; @@ -714,6 +729,20 @@ static int macsmc_power_probe(struct platform_device *pdev) if (apple_smc_key_exists(smc, SMC_KEY(CH0I))) power->has_ch0i = true; + ret = apple_smc_get_key_info(power->smc, SMC_KEY(BCF0), &info); + if (ret) { + dev_err(&pdev->dev, "Failed to determine BCF0 key size\n"); + return ret; + } + if (info.size == 1) + power->bcf0_1byte = true; + else if (info.size == 4) + power->bcf0_1byte = false; + else { + dev_err(&pdev->dev, "Unexpected BCF0 key size %d\n", info.size); + return -EIO; + } + /* Reset "Optimised Battery Charging" flags to default state */ if (power->has_chte) apple_smc_write_u32(smc, SMC_KEY(CHTE), 0); @@ -766,7 +795,7 @@ static int macsmc_power_probe(struct platform_device *pdev) power->nominal_voltage_mv = MACSMC_NOMINAL_CELL_VOLTAGE_MV * power->num_cells; /* Enable critical shutdown notifications by reading status once */ - apple_smc_read_u32(power->smc, SMC_KEY(BCF0), &val32); + macsmc_battery_read_bcf0(power, &val32); psy_cfg.drv_data = power; power->batt = devm_power_supply_register(dev, &power->batt_desc, &psy_cfg); --- base-commit: 9716c086c8e8b141d35aa61f2e96a2e83de212a7 change-id: 20260611-gate-power-cfd726dc0d7f Best regards, -- Sasha Finkelstein