[PATCH V4] i2c: tegra: Fix Maximum transfer size

[PATCH V4] i2c: tegra: Fix Maximum transfer size

[Sowjanya Komatineni]

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>
---
 drivers/i2c/busses/i2c-tegra.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 437294ea2f0a..a01834fb2ce6 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -154,6 +154,8 @@ enum msg_end_type {
  * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
  *		applicable if there is no fast clock source i.e. single clock
  *		source.
+ * @quirks: i2c adapter quirks for limiting write/read transfer size and not
+ *		allowing 0 length transfers.
  */
 
 struct tegra_i2c_hw_feature {
@@ -167,6 +169,7 @@ 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;
 };
 
 /**
@@ -833,6 +836,10 @@ static const struct i2c_adapter_quirks tegra_i2c_quirks = {
 	.max_write_len = 4096,
 };
 
+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,
@@ -844,6 +851,7 @@ 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 = {
@@ -857,6 +865,7 @@ 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 = {
@@ -870,6 +879,7 @@ 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 = {
@@ -883,6 +893,7 @@ 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 = {
@@ -896,6 +907,7 @@ 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 = {
@@ -909,6 +921,7 @@ 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 */
@@ -960,7 +973,6 @@ 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;
@@ -976,6 +988,8 @@ 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);
 
-- 
2.7.4

Re: [PATCH V4] i2c: tegra: Fix Maximum transfer size

[Wolfram Sang]

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On Thu, Jan 03, 2019 at 04:12:47PM -0800, Sowjanya Komatineni wrote:
> 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>

Looks good, but doesn't apply. Can you rebase to 5.0-rc1?


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