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From: Dmitry Osipenko <digetx@gmail.com>
To: "Thierry Reding" <thierry.reding@gmail.com>,
	"Jonathan Hunter" <jonathanh@nvidia.com>,
	"Laxman Dewangan" <ldewangan@nvidia.com>,
	"Wolfram Sang" <wsa@the-dreams.de>,
	"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
	"Andy Shevchenko" <andy.shevchenko@gmail.com>
Cc: linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v8 05/32] i2c: tegra: Initialize div-clk rate unconditionally
Date: Wed, 23 Sep 2020 01:51:28 +0300	[thread overview]
Message-ID: <20200922225155.10798-6-digetx@gmail.com> (raw)
In-Reply-To: <20200922225155.10798-1-digetx@gmail.com>

It doesn't make sense to conditionalize the div-clk rate changes because
rate is fixed and it won't ever change once it's set at the driver's probe
time. All further changes are NO-OPs because CCF caches rate and skips
rate-change if rate is unchanged.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/i2c/busses/i2c-tegra.c | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 1d1ce266255a..720a75439e91 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -293,7 +293,7 @@ struct tegra_i2c_dev {
 	bool is_curr_atomic_xfer;
 };
 
-static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit);
+static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev);
 
 static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
 		       unsigned long reg)
@@ -691,7 +691,7 @@ static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev)
 	 * domain ON.
 	 */
 	if (i2c_dev->is_vi) {
-		ret = tegra_i2c_init(i2c_dev, true);
+		ret = tegra_i2c_init(i2c_dev);
 		if (ret)
 			goto disable_div_clk;
 	}
@@ -778,7 +778,7 @@ static void tegra_i2c_vi_init(struct tegra_i2c_dev *i2c_dev)
 	i2c_writel(i2c_dev, 0x0, I2C_TLOW_SEXT);
 }
 
-static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
+static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 {
 	u32 val;
 	int err;
@@ -836,16 +836,14 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
 	if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
 		i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
 
-	if (!clk_reinit) {
-		clk_multiplier = (tlow + thigh + 2);
-		clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
-		err = clk_set_rate(i2c_dev->div_clk,
-				   i2c_dev->bus_clk_rate * clk_multiplier);
-		if (err) {
-			dev_err(i2c_dev->dev,
-				"failed changing clock rate: %d\n", err);
-			return err;
-		}
+	clk_multiplier  = tlow + thigh + 2;
+	clk_multiplier *= i2c_dev->clk_divisor_non_hs_mode + 1;
+
+	err = clk_set_rate(i2c_dev->div_clk,
+			   i2c_dev->bus_clk_rate * clk_multiplier);
+	if (err) {
+		dev_err(i2c_dev->dev, "failed to set div-clk rate: %d\n", err);
+		return err;
 	}
 
 	if (!i2c_dev->is_dvc && !i2c_dev->is_vi) {
@@ -1319,7 +1317,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 
 		if (!time_left && !completion_done(&i2c_dev->dma_complete)) {
 			dev_err(i2c_dev->dev, "DMA transfer timeout\n");
-			tegra_i2c_init(i2c_dev, true);
+			tegra_i2c_init(i2c_dev);
 			return -ETIMEDOUT;
 		}
 
@@ -1340,7 +1338,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 
 	if (time_left == 0) {
 		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
-		tegra_i2c_init(i2c_dev, true);
+		tegra_i2c_init(i2c_dev);
 		return -ETIMEDOUT;
 	}
 
@@ -1352,7 +1350,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 	if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
 		return 0;
 
-	tegra_i2c_init(i2c_dev, true);
+	tegra_i2c_init(i2c_dev);
 	/* start recovery upon arbitration loss in single master mode */
 	if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) {
 		if (!i2c_dev->is_multimaster_mode)
@@ -1811,7 +1809,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto disable_div_clk;
 
-	ret = tegra_i2c_init(i2c_dev, false);
+	ret = tegra_i2c_init(i2c_dev);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
 		goto release_dma;
@@ -1918,7 +1916,7 @@ static int __maybe_unused tegra_i2c_resume(struct device *dev)
 	if (err)
 		return err;
 
-	err = tegra_i2c_init(i2c_dev, false);
+	err = tegra_i2c_init(i2c_dev);
 	if (err)
 		return err;
 
-- 
2.27.0


  parent reply	other threads:[~2020-09-22 22:54 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-22 22:51 [PATCH v8 00/32] Improvements for Tegra I2C driver Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 01/32] i2c: tegra: Make tegra_i2c_flush_fifos() usable in atomic transfer Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 02/32] i2c: tegra: Add missing pm_runtime_put() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 03/32] i2c: tegra: Handle potential error of tegra_i2c_flush_fifos() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 04/32] i2c: tegra: Mask interrupt in tegra_i2c_issue_bus_clear() Dmitry Osipenko
2020-09-22 22:51 ` Dmitry Osipenko [this message]
2020-09-22 22:51 ` [PATCH v8 06/32] i2c: tegra: Remove i2c_dev.clk_divisor_non_hs_mode member Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 07/32] i2c: tegra: Runtime PM always available on Tegra Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 08/32] i2c: tegra: Remove error message used for devm_request_irq() failure Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 09/32] i2c: tegra: Use reset_control_reset() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 10/32] i2c: tegra: Use devm_platform_get_and_ioremap_resource() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 11/32] i2c: tegra: Use platform_get_irq() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 12/32] i2c: tegra: Use clk-bulk helpers Dmitry Osipenko
2020-09-29 19:33   ` Wolfram Sang
2020-09-29 21:01     ` Dmitry Osipenko
2020-09-29 21:46       ` Wolfram Sang
2020-09-22 22:51 ` [PATCH v8 13/32] i2c: tegra: Move out all device-tree parsing into tegra_i2c_parse_dt() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 14/32] i2c: tegra: Clean up probe function Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 15/32] i2c: tegra: Reorder location of functions in the code Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 16/32] i2c: tegra: Clean up variable types Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 17/32] i2c: tegra: Remove outdated barrier() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 18/32] i2c: tegra: Remove likely/unlikely from the code Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 19/32] i2c: tegra: Remove redundant check in tegra_i2c_issue_bus_clear() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 20/32] i2c: tegra: Remove "dma" variable from tegra_i2c_xfer_msg() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 21/32] i2c: tegra: Rename wait/poll functions Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 22/32] i2c: tegra: Factor out error recovery from tegra_i2c_xfer_msg() Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 23/32] i2c: tegra: Factor out packet header setup " Dmitry Osipenko
2020-09-29 21:16   ` Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 24/32] i2c: tegra: Factor out register polling into separate function Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 25/32] i2c: tegra: Factor out hardware initialization " Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 26/32] i2c: tegra: Check errors for both positive and negative values Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 27/32] i2c: tegra: Improve formatting of variables Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 28/32] i2c: tegra: Clean up variable names Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 29/32] i2c: tegra: Clean up printk messages Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 30/32] i2c: tegra: Clean up and improve comments Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 31/32] i2c: tegra: Clean up whitespaces, newlines and indentation Dmitry Osipenko
2020-09-22 22:51 ` [PATCH v8 32/32] i2c: tegra: Improve driver module description Dmitry Osipenko
2020-09-23  1:19 ` [PATCH v8 00/32] Improvements for Tegra I2C driver Dmitry Osipenko
2020-09-23  7:01   ` Wolfram Sang
2020-09-23 16:10     ` Dmitry Osipenko

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