power: supply: macsmc_power: Add a debug mode to print power usage

power: supply: macsmc_power: Log power data on button presses

This helps catch s2idle power stats, since we get early data when the
system resumes due to a power button press.

Signed-off-by: Hector Martin <marcan@marcan.st>

Author: marcan

drivers/power/supply/macsmc-power.c

@@ -50,8 +50,25 @@ struct macsmc_power {
 
 	struct work_struct critical_work;
 	bool shutdown_started;
+
+	struct delayed_work dbg_log_work;
+};
+
+static int macsmc_log_power_set(const char *val, const struct kernel_param *kp);
+
+static const struct kernel_param_ops macsmc_log_power_ops = {
+        .set = macsmc_log_power_set,
+        .get = param_get_bool,
 };
 
+static bool log_power = false;
+module_param_cb(log_power, &macsmc_log_power_ops, &log_power, 0644);
+MODULE_PARM_DESC(log_power, "Periodically log power consumption for debugging");
+
+#define POWER_LOG_INTERVAL (HZ)
+
+static struct macsmc_power *g_power;
+
 #define CHNC_BATTERY_FULL	BIT(0)
 #define CHNC_NO_CHARGER		BIT(7)
 #define CHNC_NOCHG_CH0C		BIT(14)
@@ -82,6 +99,88 @@ struct macsmc_power {
 #define CHWA_FIXED_END_THRESHOLD	80
 #define CHWA_PROP_WRITE_THRESHOLD	95
 
+#define FLT_EXP_BIAS	127
+#define FLT_EXP_MASK	GENMASK(30, 23)
+#define FLT_MANT_BIAS	23
+#define FLT_MANT_MASK	GENMASK(22, 0)
+#define FLT_SIGN_MASK	BIT(31)
+/*
+ * Many sensors report their data as IEEE-754 floats. No other SMC function uses
+ * them.
+ */
+static int apple_smc_read_f32_scaled(struct apple_smc *smc, smc_key key,
+					int *p, int scale)
+{
+	u32 fval;
+	u64 val;
+	int ret, exp;
+
+	BUILD_BUG_ON(scale <= 0);
+
+	ret = apple_smc_read_u32(smc, key, &fval);
+	if (ret < 0)
+		return ret;
+
+	val = ((u64)((fval & FLT_MANT_MASK) | BIT(23)));
+	exp = ((fval >> 23) & 0xff) - FLT_EXP_BIAS - FLT_MANT_BIAS;
+	val *= scale;
+
+	if (exp > 63)
+		val = U64_MAX;
+	else if (exp < -63)
+		val = 0;
+	else if (exp < 0)
+		val >>= -exp;
+	else if (exp != 0 && (val & ~((1UL << (64 - exp)) - 1))) /* overflow */
+		val = U64_MAX;
+	else
+		val <<= exp;
+
+	if (fval & FLT_SIGN_MASK) {
+		if (val > (-(s64)INT_MIN))
+			*p = INT_MIN;
+		else
+			*p = -val;
+	} else {
+		if (val > INT_MAX)
+			*p = INT_MAX;
+		else
+			*p = val;
+	}
+
+	return 0;
+}
+
+static void macsmc_do_dbg(struct macsmc_power *power)
+{
+	int p_in = 0, p_sys = 0, p_3v8 = 0, p_mpmu = 0, p_spmu = 0, p_clvr = 0, p_cpu = 0;
+	s32 p_bat = 0;
+	s16 t_full = 0, t_empty = 0;
+	u8 charge = 0;
+
+	apple_smc_read_f32_scaled(power->smc, SMC_KEY(PDTR), &p_in, 1000);
+	apple_smc_read_f32_scaled(power->smc, SMC_KEY(PSTR), &p_sys, 1000);
+	apple_smc_read_f32_scaled(power->smc, SMC_KEY(PMVR), &p_3v8, 1000);
+	apple_smc_read_f32_scaled(power->smc, SMC_KEY(PHPC), &p_cpu, 1000);
+	apple_smc_read_f32_scaled(power->smc, SMC_KEY(PSVR), &p_clvr, 1000);
+	apple_smc_read_f32_scaled(power->smc, SMC_KEY(PPMC), &p_mpmu, 1000);
+	apple_smc_read_f32_scaled(power->smc, SMC_KEY(PPSC), &p_spmu, 1000);
+	apple_smc_read_s32(power->smc, SMC_KEY(B0AP), &p_bat);
+	apple_smc_read_s16(power->smc, SMC_KEY(B0TE), &t_empty);
+	apple_smc_read_s16(power->smc, SMC_KEY(B0TF), &t_full);
+	apple_smc_read_u8(power->smc, SMC_KEY(BUIC), &charge);
+
+#define FD3(x) ((x) / 1000), abs((x) % 1000)
+	dev_info(power->dev,
+		 "In %2d.%03dW Sys %2d.%03dW 3V8 %2d.%03dW MPMU %2d.%03dW SPMU %2d.%03dW "
+		 "CLVR %2d.%03dW CPU %2d.%03dW Batt %2d.%03dW %d%% T%s %dm\n",
+		 FD3(p_in), FD3(p_sys), FD3(p_3v8), FD3(p_mpmu), FD3(p_spmu), FD3(p_clvr),
+		 FD3(p_cpu), FD3(p_bat), charge,
+		 t_full >= 0 ? "full" : "empty",
+		 t_full >= 0 ? t_full : t_empty);
+#undef FD3
+}
+
 static int macsmc_battery_get_status(struct macsmc_power *power)
 {
 	u64 nocharge_flags;
@@ -610,6 +709,30 @@ static const struct power_supply_desc macsmc_ac_desc = {
 	.num_properties		= ARRAY_SIZE(macsmc_ac_props),
 };
 
+static int macsmc_log_power_set(const char *val, const struct kernel_param *kp)
+{
+	int ret = param_set_bool(val, kp);
+
+	if (ret < 0)
+		return ret;
+
+	if (log_power && g_power)
+		schedule_delayed_work(&g_power->dbg_log_work, 0);
+
+	return 0;
+}
+
+static void macsmc_dbg_work(struct work_struct *wrk)
+{
+	struct macsmc_power *power = container_of(to_delayed_work(wrk),
+						  struct macsmc_power, dbg_log_work);
+
+	macsmc_do_dbg(power);
+
+	if (log_power)
+		schedule_delayed_work(&power->dbg_log_work, POWER_LOG_INTERVAL);
+}
+
 static void macsmc_power_critical_work(struct work_struct *wrk)
 {
 	struct macsmc_power *power = container_of(wrk, struct macsmc_power, critical_work);
@@ -699,6 +822,10 @@ static int macsmc_power_event(struct notifier_block *nb, unsigned long event, vo
 
 		return NOTIFY_OK;
 	} else if ((event & 0xffff0000) == 0x72010000) {
+		/* Button event handled by macsmc-hid, but let's do a debug print */
+		if (log_power)
+			macsmc_do_dbg(power);
+
 		return NOTIFY_OK;
 	}
 
@@ -781,6 +908,12 @@ static int macsmc_power_probe(struct platform_device *pdev)
 	blocking_notifier_chain_register(&smc->event_handlers, &power->nb);
 
 	INIT_WORK(&power->critical_work, macsmc_power_critical_work);
+	INIT_DELAYED_WORK(&power->dbg_log_work, macsmc_dbg_work);
+
+	g_power = power;
+
+	if (log_power)
+		schedule_delayed_work(&power->dbg_log_work, 0);
 
 	return 0;
 }
@@ -790,6 +923,9 @@ static void macsmc_power_remove(struct platform_device *pdev)
 	struct macsmc_power *power = dev_get_drvdata(&pdev->dev);
 
 	cancel_work(&power->critical_work);
+	cancel_delayed_work(&power->dbg_log_work);
+
+	g_power = NULL;
 
 	blocking_notifier_chain_unregister(&power->smc->event_handlers, &power->nb);
 }