From: Wolfram Sang <wsa@the-dreams.de> To: linux-i2c@vger.kernel.org Cc: linux-sh@vger.kernel.org, Magnus Damm <magnus.damm@gmail.com>, Simon Horman <horms@verge.net.au>, Laurent Pinchart <laurent.pinchart@ideasonboard.com>, Geert Uytterhoeven <geert@linux-m68k.org>, Wolfram Sang <wsa@the-dreams.de>, Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>, linux-rockchip@lists.infradead.org, Mika Westerberg <mika.westerberg@linux.intel.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Jarkko Nikula <jarkko.nikula@linux.intel.com> Subject: [PATCH 5/9] i2c: rcar: honor additional i2c timings from DT Date: Thu, 03 Dec 2015 15:51:35 +0000 [thread overview] Message-ID: <1449157899-6572-6-git-send-email-wsa@the-dreams.de> (raw) In-Reply-To: <1449157899-6572-1-git-send-email-wsa@the-dreams.de> From: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- Documentation/devicetree/bindings/i2c/i2c-rcar.txt | 4 ++++ drivers/i2c/busses/i2c-rcar.c | 21 ++++++++++++--------- 2 files changed, 16 insertions(+), 9 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt index ea406eb20fa5ad..95e97223a71c83 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt @@ -20,6 +20,10 @@ Optional properties: propoerty indicates the default frequency 100 kHz. - clocks: clock specifier. +- i2c-scl-falling-time-ns: see i2c.txt +- i2c-scl-internal-delay-ns: see i2c.txt +- i2c-scl-rising-time-ns: see i2c.txt + Examples : i2c0: i2c@e6508000 { diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 05274fda57eb08..cd1796e51764ee 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -164,12 +164,15 @@ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timings *t) { - u32 scgd, cdf, round, ick, scl, cdf_width; + u32 scgd, cdf, round, ick, sum, scl, cdf_width; unsigned long rate; struct device *dev = rcar_i2c_priv_to_dev(priv); /* Fall back to previously used values if not supplied */ t->bus_freq_hz = t->bus_freq_hz ?: 100000; + t->scl_fall_ns = t->scl_fall_ns ?: 35; + t->scl_rise_ns = t->scl_rise_ns ?: 200; + t->scl_int_delay_ns = t->scl_int_delay_ns ?: 50; switch (priv->devtype) { case I2C_RCAR_GEN1: @@ -193,9 +196,9 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timin * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick]) * * ick : I2C internal clock < 20 MHz - * ticf : I2C SCL falling time = 35 ns here - * tr : I2C SCL rising time = 200 ns here - * intd : LSI internal delay = 50 ns here + * ticf : I2C SCL falling time + * tr : I2C SCL rising time + * intd : LSI internal delay * clkp : peripheral_clk * F[] : integer up-valuation */ @@ -211,12 +214,12 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timin * it is impossible to calculate large scale * number on u32. separate it * - * F[(ticf + tr + intd) * ick] - * = F[(35 + 200 + 50)ns * ick] - * = F[285 * ick / 1000000000] - * = F[(ick / 1000000) * 285 / 1000] + * F[(ticf + tr + intd) * ick] with sum = (ticf + tr + intd) + * = F[sum * ick / 1000000000] + * = F[(ick / 1000000) * sum / 1000] */ - round = (ick + 500000) / 1000000 * 285; + sum = t->scl_fall_ns + t->scl_rise_ns + t->scl_int_delay_ns; + round = (ick + 500000) / 1000000 * sum; round = (round + 500) / 1000; /* -- 2.1.4
WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de> To: linux-i2c@vger.kernel.org Cc: linux-sh@vger.kernel.org, Magnus Damm <magnus.damm@gmail.com>, Simon Horman <horms@verge.net.au>, Laurent Pinchart <laurent.pinchart@ideasonboard.com>, Geert Uytterhoeven <geert@linux-m68k.org>, Wolfram Sang <wsa@the-dreams.de>, Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>, linux-rockchip@lists.infradead.org, Mika Westerberg <mika.westerberg@linux.intel.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Jarkko Nikula <jarkko.nikula@linux.intel.com> Subject: [PATCH 5/9] i2c: rcar: honor additional i2c timings from DT Date: Thu, 3 Dec 2015 16:51:35 +0100 [thread overview] Message-ID: <1449157899-6572-6-git-send-email-wsa@the-dreams.de> (raw) In-Reply-To: <1449157899-6572-1-git-send-email-wsa@the-dreams.de> From: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- Documentation/devicetree/bindings/i2c/i2c-rcar.txt | 4 ++++ drivers/i2c/busses/i2c-rcar.c | 21 ++++++++++++--------- 2 files changed, 16 insertions(+), 9 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt index ea406eb20fa5ad..95e97223a71c83 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt @@ -20,6 +20,10 @@ Optional properties: propoerty indicates the default frequency 100 kHz. - clocks: clock specifier. +- i2c-scl-falling-time-ns: see i2c.txt +- i2c-scl-internal-delay-ns: see i2c.txt +- i2c-scl-rising-time-ns: see i2c.txt + Examples : i2c0: i2c@e6508000 { diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 05274fda57eb08..cd1796e51764ee 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -164,12 +164,15 @@ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timings *t) { - u32 scgd, cdf, round, ick, scl, cdf_width; + u32 scgd, cdf, round, ick, sum, scl, cdf_width; unsigned long rate; struct device *dev = rcar_i2c_priv_to_dev(priv); /* Fall back to previously used values if not supplied */ t->bus_freq_hz = t->bus_freq_hz ?: 100000; + t->scl_fall_ns = t->scl_fall_ns ?: 35; + t->scl_rise_ns = t->scl_rise_ns ?: 200; + t->scl_int_delay_ns = t->scl_int_delay_ns ?: 50; switch (priv->devtype) { case I2C_RCAR_GEN1: @@ -193,9 +196,9 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timin * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick]) * * ick : I2C internal clock < 20 MHz - * ticf : I2C SCL falling time = 35 ns here - * tr : I2C SCL rising time = 200 ns here - * intd : LSI internal delay = 50 ns here + * ticf : I2C SCL falling time + * tr : I2C SCL rising time + * intd : LSI internal delay * clkp : peripheral_clk * F[] : integer up-valuation */ @@ -211,12 +214,12 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timin * it is impossible to calculate large scale * number on u32. separate it * - * F[(ticf + tr + intd) * ick] - * = F[(35 + 200 + 50)ns * ick] - * = F[285 * ick / 1000000000] - * = F[(ick / 1000000) * 285 / 1000] + * F[(ticf + tr + intd) * ick] with sum = (ticf + tr + intd) + * = F[sum * ick / 1000000000] + * = F[(ick / 1000000) * sum / 1000] */ - round = (ick + 500000) / 1000000 * 285; + sum = t->scl_fall_ns + t->scl_rise_ns + t->scl_int_delay_ns; + round = (ick + 500000) / 1000000 * sum; round = (round + 500) / 1000; /* -- 2.1.4
next prev parent reply other threads:[~2015-12-03 15:51 UTC|newest] Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-12-03 15:51 [PATCH 0/9] i2c: add generic support for timing parameters in DT Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang [not found] ` <1449157899-6572-1-git-send-email-wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org> 2015-12-03 15:51 ` [PATCH 1/9] i2c: document generic DT bindings for timing parameters Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-03 20:39 ` Rob Herring 2015-12-03 20:39 ` Rob Herring 2015-12-03 15:51 ` [PATCH 2/9] i2c: add generic routine to parse DT for timing information Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-04 8:34 ` Mika Westerberg 2015-12-04 8:34 ` Mika Westerberg 2015-12-04 8:41 ` Wolfram Sang 2015-12-04 8:41 ` Wolfram Sang 2015-12-03 15:51 ` [PATCH 3/9] i2c: rcar: refactor probe function a little Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-03 15:51 ` [PATCH 4/9] i2c: rcar: switch to i2c generic dt parsing Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang [this message] 2015-12-03 15:51 ` [PATCH 5/9] i2c: rcar: honor additional i2c timings from DT Wolfram Sang 2015-12-03 15:51 ` [PATCH 6/9] ARM: shmobile: r8a7790: dtsi: add internal delay for i2c IPs Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-03 15:51 ` [PATCH 7/9] ARM: shmobile: r8a7791: " Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-03 15:51 ` [PATCH 8/9] ARM: shmobile: r8a7794: " Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-03 15:51 ` [PATCH 9/9] arm64: renesas: r8a7795: " Wolfram Sang 2015-12-03 15:51 ` Wolfram Sang 2015-12-07 6:39 ` [PATCH 0/9] i2c: add generic support for timing parameters in DT Simon Horman 2015-12-07 6:39 ` Simon Horman
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1449157899-6572-6-git-send-email-wsa@the-dreams.de \ --to=wsa@the-dreams.de \ --cc=andriy.shevchenko@linux.intel.com \ --cc=geert@linux-m68k.org \ --cc=horms@verge.net.au \ --cc=jarkko.nikula@linux.intel.com \ --cc=laurent.pinchart@ideasonboard.com \ --cc=linux-i2c@vger.kernel.org \ --cc=linux-rockchip@lists.infradead.org \ --cc=linux-sh@vger.kernel.org \ --cc=magnus.damm@gmail.com \ --cc=mika.westerberg@linux.intel.com \ --cc=yoshihiro.shimoda.uh@renesas.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.