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From:   Alex Elder <elder@linaro.org>
To:     robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com
Cc:     andersson@kernel.org, konrad.dybcio@linaro.org, agross@kernel.org,
        elder@kernel.org, linux-arm-msm@vger.kernel.org,
        netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net-next v2 2/5] net: ipa: encapsulate decision about firmware load
Date:   Tue, 15 Nov 2022 05:31:16 -0600
Message-Id: <20221115113119.249893-3-elder@linaro.org>
In-Reply-To: <20221115113119.249893-1-elder@linaro.org>
References: <20221115113119.249893-1-elder@linaro.org>
MIME-Version: 1.0
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The GSI layer used for IPA requires firmware to be loaded.

Currently either the AP or the modem loads the firmware,
distinguished by whether the "modem-init" Device Tree
property is defined.

Some newer systems implement a third option.  In preparation for
that, encapsulate the code that determines how the GSI firmware
gets loaded in a new function, ipa_firmware_loader().

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_main.c | 39 ++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index ebb6c9b311eb9..9e43b79d233e9 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -81,6 +81,19 @@
 /* Divider for 19.2 MHz crystal oscillator clock to get common timer clock */
 #define IPA_XO_CLOCK_DIVIDER	192	/* 1 is subtracted where used */
 
+/**
+ * enum ipa_firmware_loader: How GSI firmware gets loaded
+ *
+ * @IPA_LOADER_DEFER:		System not ready; try again later
+ * @IPA_LOADER_SELF:		AP loads GSI firmware
+ * @IPA_LOADER_MODEM:		Modem loads GSI firmware, signals when done
+ */
+enum ipa_firmware_loader {
+	IPA_LOADER_DEFER,
+	IPA_LOADER_SELF,
+	IPA_LOADER_MODEM,
+};
+
 /**
  * ipa_setup() - Set up IPA hardware
  * @ipa:	IPA pointer
@@ -696,6 +709,18 @@ static void ipa_validate_build(void)
 	BUILD_BUG_ON(!ipa_aggr_granularity_val(IPA_AGGR_GRANULARITY));
 }
 
+static enum ipa_firmware_loader ipa_firmware_loader(struct device *dev)
+{
+	if (of_property_read_bool(dev->of_node, "modem-init"))
+		return IPA_LOADER_MODEM;
+
+	/* We need Trust Zone to load firmware; make sure it's available */
+	if (qcom_scm_is_available())
+		return IPA_LOADER_SELF;
+
+	return IPA_LOADER_DEFER;
+}
+
 /**
  * ipa_probe() - IPA platform driver probe function
  * @pdev:	Platform device pointer
@@ -722,9 +747,9 @@ static void ipa_validate_build(void)
 static int ipa_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	enum ipa_firmware_loader loader;
 	const struct ipa_data *data;
 	struct ipa_power *power;
-	bool modem_init;
 	struct ipa *ipa;
 	int ret;
 
@@ -747,11 +772,9 @@ static int ipa_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	/* If we need Trust Zone, make sure it's available */
-	modem_init = of_property_read_bool(dev->of_node, "modem-init");
-	if (!modem_init)
-		if (!qcom_scm_is_available())
-			return -EPROBE_DEFER;
+	loader = ipa_firmware_loader(dev);
+	if (loader == IPA_LOADER_DEFER)
+		return -EPROBE_DEFER;
 
 	/* The clock and interconnects might not be ready when we're
 	 * probed, so might return -EPROBE_DEFER.
@@ -796,7 +819,7 @@ static int ipa_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_endpoint_exit;
 
-	ret = ipa_smp2p_init(ipa, modem_init);
+	ret = ipa_smp2p_init(ipa, loader == IPA_LOADER_MODEM);
 	if (ret)
 		goto err_table_exit;
 
@@ -815,7 +838,7 @@ static int ipa_probe(struct platform_device *pdev)
 	 * call to ipa_setup() when it has finished.  In that case we're
 	 * done here.
 	 */
-	if (modem_init)
+	if (loader == IPA_LOADER_MODEM)
 		goto done;
 
 	/* Otherwise we need to load the firmware and have Trust Zone validate
-- 
2.34.1