From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: [PATCH v2 05/10] i2c: meson: set clock divider in probe instead of setting it for each transfer Date: Thu, 9 Mar 2017 07:42:08 +0100 Message-ID: <5fcfa996-5986-1856-d6f7-a979b7c5d5c9@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wr0-f195.google.com ([209.85.128.195]:35716 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751355AbdCIHLK (ORCPT ); Thu, 9 Mar 2017 02:11:10 -0500 Received: by mail-wr0-f195.google.com with SMTP id u108so6747659wrb.2 for ; Wed, 08 Mar 2017 23:11:09 -0800 (PST) In-Reply-To: Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Wolfram Sang , Jerome Brunet Cc: "linux-i2c@vger.kernel.org" , linux-amlogic@lists.infradead.org The bus frequency won't change, therefore we can set the clock divider in probe already and we don't have to set it for each transfer. Signed-off-by: Heiner Kallweit --- v2: - no changes --- drivers/i2c/busses/i2c-meson.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c index a5764be5..594fec22 100644 --- a/drivers/i2c/busses/i2c-meson.c +++ b/drivers/i2c/busses/i2c-meson.c @@ -74,7 +74,6 @@ enum { * @error: Flag set when an error is received * @lock: To avoid race conditions between irq handler and xfer code * @done: Completion used to wait for transfer termination - * @timings: Struct including the bus frequency * @tokens: Sequence of tokens to be written to the device * @num_tokens: Number of tokens */ @@ -93,7 +92,6 @@ struct meson_i2c { spinlock_t lock; struct completion done; - struct i2c_timings timings; u32 tokens[2]; int num_tokens; }; @@ -132,12 +130,12 @@ static void meson_i2c_write_tokens(struct meson_i2c *i2c) writel(i2c->tokens[1], i2c->regs + REG_TOK_LIST1); } -static void meson_i2c_set_clk_div(struct meson_i2c *i2c) +static void meson_i2c_set_clk_div(struct meson_i2c *i2c, unsigned int freq) { unsigned long clk_rate = clk_get_rate(i2c->clk); unsigned int div; - div = DIV_ROUND_UP(clk_rate, i2c->timings.bus_freq_hz * 4); + div = DIV_ROUND_UP(clk_rate, freq * 4); /* clock divider has 12 bits */ WARN_ON(div >= (1 << 12)); @@ -149,7 +147,7 @@ static void meson_i2c_set_clk_div(struct meson_i2c *i2c) (div >> 10) << REG_CTRL_CLKDIVEXT_SHIFT); dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__, - clk_rate, i2c->timings.bus_freq_hz, div); + clk_rate, freq, div); } static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len) @@ -369,7 +367,6 @@ static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int i, ret = 0, count = 0; clk_enable(i2c->clk); - meson_i2c_set_clk_div(i2c); for (i = 0; i < num; i++) { ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1); @@ -396,6 +393,7 @@ static const struct i2c_algorithm meson_i2c_algorithm = { static int meson_i2c_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; + struct i2c_timings timings; struct meson_i2c *i2c; struct resource *mem; int irq, ret = 0; @@ -404,7 +402,7 @@ static int meson_i2c_probe(struct platform_device *pdev) if (!i2c) return -ENOMEM; - i2c_parse_fw_timings(&pdev->dev, &i2c->timings, true); + i2c_parse_fw_timings(&pdev->dev, &timings, true); i2c->dev = &pdev->dev; platform_set_drvdata(pdev, i2c); @@ -462,6 +460,8 @@ static int meson_i2c_probe(struct platform_device *pdev) return ret; } + meson_i2c_set_clk_div(i2c, timings.bus_freq_hz); + return 0; } -- 2.12.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: hkallweit1@gmail.com (Heiner Kallweit) Date: Thu, 9 Mar 2017 07:42:08 +0100 Subject: [PATCH v2 05/10] i2c: meson: set clock divider in probe instead of setting it for each transfer In-Reply-To: References: Message-ID: <5fcfa996-5986-1856-d6f7-a979b7c5d5c9@gmail.com> To: linus-amlogic@lists.infradead.org List-Id: linus-amlogic.lists.infradead.org The bus frequency won't change, therefore we can set the clock divider in probe already and we don't have to set it for each transfer. Signed-off-by: Heiner Kallweit --- v2: - no changes --- drivers/i2c/busses/i2c-meson.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c index a5764be5..594fec22 100644 --- a/drivers/i2c/busses/i2c-meson.c +++ b/drivers/i2c/busses/i2c-meson.c @@ -74,7 +74,6 @@ enum { * @error: Flag set when an error is received * @lock: To avoid race conditions between irq handler and xfer code * @done: Completion used to wait for transfer termination - * @timings: Struct including the bus frequency * @tokens: Sequence of tokens to be written to the device * @num_tokens: Number of tokens */ @@ -93,7 +92,6 @@ struct meson_i2c { spinlock_t lock; struct completion done; - struct i2c_timings timings; u32 tokens[2]; int num_tokens; }; @@ -132,12 +130,12 @@ static void meson_i2c_write_tokens(struct meson_i2c *i2c) writel(i2c->tokens[1], i2c->regs + REG_TOK_LIST1); } -static void meson_i2c_set_clk_div(struct meson_i2c *i2c) +static void meson_i2c_set_clk_div(struct meson_i2c *i2c, unsigned int freq) { unsigned long clk_rate = clk_get_rate(i2c->clk); unsigned int div; - div = DIV_ROUND_UP(clk_rate, i2c->timings.bus_freq_hz * 4); + div = DIV_ROUND_UP(clk_rate, freq * 4); /* clock divider has 12 bits */ WARN_ON(div >= (1 << 12)); @@ -149,7 +147,7 @@ static void meson_i2c_set_clk_div(struct meson_i2c *i2c) (div >> 10) << REG_CTRL_CLKDIVEXT_SHIFT); dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__, - clk_rate, i2c->timings.bus_freq_hz, div); + clk_rate, freq, div); } static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len) @@ -369,7 +367,6 @@ static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int i, ret = 0, count = 0; clk_enable(i2c->clk); - meson_i2c_set_clk_div(i2c); for (i = 0; i < num; i++) { ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1); @@ -396,6 +393,7 @@ static const struct i2c_algorithm meson_i2c_algorithm = { static int meson_i2c_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; + struct i2c_timings timings; struct meson_i2c *i2c; struct resource *mem; int irq, ret = 0; @@ -404,7 +402,7 @@ static int meson_i2c_probe(struct platform_device *pdev) if (!i2c) return -ENOMEM; - i2c_parse_fw_timings(&pdev->dev, &i2c->timings, true); + i2c_parse_fw_timings(&pdev->dev, &timings, true); i2c->dev = &pdev->dev; platform_set_drvdata(pdev, i2c); @@ -462,6 +460,8 @@ static int meson_i2c_probe(struct platform_device *pdev) return ret; } + meson_i2c_set_clk_div(i2c, timings.bus_freq_hz); + return 0; } -- 2.12.0