From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: Re: [PATCH v2 03/10] i2c: meson: use i2c core for DT clock-frequency parsing Date: Thu, 9 Mar 2017 21:13:56 +0100 Message-ID: <0fdb72c8-1689-aad7-ff53-66a73a954dce@gmail.com> References: <1b175225-9cb1-6c7c-3175-dcba8189fefe@gmail.com> <03a32142-8787-b4e2-c895-02709cc5298f@baylibre.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wr0-f195.google.com ([209.85.128.195]:33869 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750991AbdCIUQ1 (ORCPT ); Thu, 9 Mar 2017 15:16:27 -0500 Received: by mail-wr0-f195.google.com with SMTP id u48so9283913wrc.1 for ; Thu, 09 Mar 2017 12:16:26 -0800 (PST) In-Reply-To: <03a32142-8787-b4e2-c895-02709cc5298f@baylibre.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Neil Armstrong , Wolfram Sang , Jerome Brunet Cc: linux-amlogic@lists.infradead.org, "linux-i2c@vger.kernel.org" Am 09.03.2017 um 09:26 schrieb Neil Armstrong: > On 03/09/2017 07:39 AM, Heiner Kallweit wrote: >> We don't have to parse the DT manually to retrieve the bus frequency >> and we don't have to maintain an own default for the bus frequency. >> Let the i2c core do this for us. >> >> Signed-off-by: Heiner Kallweit >> Reviewed-by: Jerome Brunet >> --- >> v2: >> - added Reviewed-by >> --- >> drivers/i2c/busses/i2c-meson.c | 13 +++++-------- >> 1 file changed, 5 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c >> index 50059d09..5e243efa 100644 >> --- a/drivers/i2c/busses/i2c-meson.c >> +++ b/drivers/i2c/busses/i2c-meson.c >> @@ -38,7 +38,6 @@ >> #define REG_CTRL_CLKDIV_MASK ((BIT(10) - 1) << REG_CTRL_CLKDIV_SHIFT) >> >> #define I2C_TIMEOUT_MS 500 >> -#define DEFAULT_FREQ 100000 >> >> enum { >> TOKEN_END = 0, >> @@ -73,7 +72,7 @@ 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 >> - * @frequency: Operating frequency of I2C bus clock >> + * @timings: Struct including the bus frequency >> * @tokens: Sequence of tokens to be written to the device >> * @num_tokens: Number of tokens >> */ >> @@ -92,7 +91,7 @@ struct meson_i2c { >> >> spinlock_t lock; >> struct completion done; >> - unsigned int frequency; >> + struct i2c_timings timings; >> u32 tokens[2]; >> int num_tokens; >> }; >> @@ -136,12 +135,12 @@ static void meson_i2c_set_clk_div(struct meson_i2c *i2c) >> unsigned long clk_rate = clk_get_rate(i2c->clk); >> unsigned int div; >> >> - div = DIV_ROUND_UP(clk_rate, i2c->frequency * 4); >> + div = DIV_ROUND_UP(clk_rate, i2c->timings.bus_freq_hz * 4); >> meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIV_MASK, >> div << REG_CTRL_CLKDIV_SHIFT); >> >> dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__, >> - clk_rate, i2c->frequency, div); >> + clk_rate, i2c->timings.bus_freq_hz, div); >> } >> >> static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len) >> @@ -396,9 +395,7 @@ static int meson_i2c_probe(struct platform_device *pdev) >> if (!i2c) >> return -ENOMEM; >> >> - if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", >> - &i2c->frequency)) >> - i2c->frequency = DEFAULT_FREQ; >> + i2c_parse_fw_timings(&pdev->dev, &i2c->timings, true); >> >> i2c->dev = &pdev->dev; >> platform_set_drvdata(pdev, i2c); >> > > Hi Heiner, > > Please update the bindings in Documentation/devicetree/bindings/i2c/i2c-meson.txt > for these new optional attributes by adding : > Hi Neil, not sure which new attributes you mean. i2c_parse_fw_timings parses additional attributes (apart from bus frequency), that right. But they are not used by the driver and therefore effectively aren't supported. Heiner > ---><----- > Please also refer to i2c.txt in this directory for common i2c > controller binding usage. > ---><----- > > With this additional patch : > Reviewed-by: Neil Armstrong > > Neil >