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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Sowjanya Komatineni <skomatineni@nvidia.com>,
        Thierry Reding <treding@nvidia.com>,
        Wolfram Sang <wsa@the-dreams.de>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 010/131] i2c: tegra: Fix Maximum transfer size
Date:   Mon, 29 Jun 2020 11:33:01 -0400
Message-Id: <20200629153502.2494656-11-sashal@kernel.org>
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From: Sowjanya Komatineni <skomatineni@nvidia.com>

[ Upstream commit b67d4530cdade7ebfafa2c6b46f2a0dad3e41bcb ]

Tegra194 supports maximum 64K Bytes transfer per packet.
Tegra186 and prior supports maximum 4K Bytes transfer per packet.

This patch fixes this payload difference between Tegra194 and prior
Tegra chipsets using separate i2c_adapter_quirks.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-tegra.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 917f416787b10..af06198851f1b 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -164,6 +164,8 @@ enum msg_end_type {
  * @has_mst_fifo: The I2C controller contains the new MST FIFO interface that
  *		provides additional features and allows for longer messages to
  *		be transferred in one go.
+ * @quirks: i2c adapter quirks for limiting write/read transfer size and not
+ *		allowing 0 length transfers.
  */
 struct tegra_i2c_hw_feature {
 	bool has_continue_xfer_support;
@@ -176,6 +178,7 @@ struct tegra_i2c_hw_feature {
 	bool has_multi_master_mode;
 	bool has_slcg_override_reg;
 	bool has_mst_fifo;
+	const struct i2c_adapter_quirks *quirks;
 };
 
 /**
@@ -847,6 +850,10 @@ static const struct i2c_adapter_quirks tegra_i2c_quirks = {
 	.max_write_len = 4096 - 12,
 };
 
+static const struct i2c_adapter_quirks tegra194_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
 	.has_continue_xfer_support = false,
 	.has_per_pkt_xfer_complete_irq = false,
@@ -858,6 +865,7 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = false,
 	.has_mst_fifo = false,
+	.quirks = &tegra_i2c_quirks,
 };
 
 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
@@ -871,6 +879,7 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = false,
 	.has_mst_fifo = false,
+	.quirks = &tegra_i2c_quirks,
 };
 
 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
@@ -884,6 +893,7 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = false,
 	.has_mst_fifo = false,
+	.quirks = &tegra_i2c_quirks,
 };
 
 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
@@ -897,6 +907,7 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = true,
 	.has_mst_fifo = false,
+	.quirks = &tegra_i2c_quirks,
 };
 
 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
@@ -910,6 +921,7 @@ static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
 	.has_multi_master_mode = true,
 	.has_slcg_override_reg = true,
 	.has_mst_fifo = false,
+	.quirks = &tegra_i2c_quirks,
 };
 
 static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
@@ -923,6 +935,7 @@ static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
 	.has_multi_master_mode = true,
 	.has_slcg_override_reg = true,
 	.has_mst_fifo = true,
+	.quirks = &tegra194_i2c_quirks,
 };
 
 /* Match table for of_platform binding */
@@ -974,7 +987,6 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	i2c_dev->base = base;
 	i2c_dev->div_clk = div_clk;
 	i2c_dev->adapter.algo = &tegra_i2c_algo;
-	i2c_dev->adapter.quirks = &tegra_i2c_quirks;
 	i2c_dev->irq = irq;
 	i2c_dev->cont_id = pdev->id;
 	i2c_dev->dev = &pdev->dev;
@@ -990,6 +1002,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	i2c_dev->hw = of_device_get_match_data(&pdev->dev);
 	i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
 						  "nvidia,tegra20-i2c-dvc");
+	i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
 	init_completion(&i2c_dev->msg_complete);
 	spin_lock_init(&i2c_dev->xfer_lock);
 
-- 
2.25.1