From mboxrd@z Thu Jan 1 00:00:00 1970 From: Akash Asthana Subject: Re: [PATCH V2 5/8] i2c: i2c-qcom-geni: Add interconnect support Date: Tue, 17 Mar 2020 17:21:03 +0530 Message-ID: References: <1584105134-13583-1-git-send-email-akashast@codeaurora.org> <1584105134-13583-6-git-send-email-akashast@codeaurora.org> <20200314001728.GL144492@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200314001728.GL144492@google.com> Content-Language: en-US Sender: linux-serial-owner@vger.kernel.org To: Matthias Kaehlcke Cc: gregkh@linuxfoundation.org, agross@kernel.org, bjorn.andersson@linaro.org, wsa@the-dreams.de, broonie@kernel.org, mark.rutland@arm.com, robh+dt@kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, swboyd@chromium.org, mgautam@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org, dianders@chromium.org, evgreen@chromium.org List-Id: linux-i2c@vger.kernel.org Hi Matthias, On 3/14/2020 5:47 AM, Matthias Kaehlcke wrote: > Hi, > > On Fri, Mar 13, 2020 at 06:42:11PM +0530, Akash Asthana wrote: >> Get the interconnect paths for I2C based Serial Engine device >> and vote according to the bus speed of the driver. >> >> Signed-off-by: Akash Asthana >> --- >> Changes in V2: >> - As per Bjorn's comment, removed se == NULL check from geni_i2c_icc_get >> - As per Bjorn's comment, removed code to set se->icc_path* to NULL in failure >> - As per Bjorn's comment, introduced and using devm_of_icc_get API for getting >> path handle >> - As per Matthias comment, added error handling for icc_set_bw call >> >> drivers/i2c/busses/i2c-qcom-geni.c | 110 +++++++++++++++++++++++++++++++++++++ >> 1 file changed, 110 insertions(+) >> >> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c >> index 17abf60c..33ab685 100644 >> --- a/drivers/i2c/busses/i2c-qcom-geni.c >> +++ b/drivers/i2c/busses/i2c-qcom-geni.c >> @@ -163,6 +163,23 @@ static void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c) >> writel_relaxed(val, gi2c->se.base + SE_I2C_SCL_COUNTERS); >> } >> >> +static int geni_i2c_icc_get(struct geni_se *se) >> +{ >> + se->icc_path_geni_to_core = devm_of_icc_get(se->dev, "qup-core"); >> + if (IS_ERR(se->icc_path_geni_to_core)) >> + return PTR_ERR(se->icc_path_geni_to_core); >> + >> + se->icc_path_cpu_to_geni = devm_of_icc_get(se->dev, "qup-config"); >> + if (IS_ERR(se->icc_path_cpu_to_geni)) >> + return PTR_ERR(se->icc_path_cpu_to_geni); >> + >> + se->icc_path_geni_to_ddr = devm_of_icc_get(se->dev, "qup-memory"); >> + if (IS_ERR(se->icc_path_geni_to_ddr)) >> + return PTR_ERR(se->icc_path_geni_to_ddr); >> + >> + return 0; >> +} >> + >> static void geni_i2c_err_misc(struct geni_i2c_dev *gi2c) >> { >> u32 m_cmd = readl_relaxed(gi2c->se.base + SE_GENI_M_CMD0); >> @@ -563,6 +580,39 @@ static int geni_i2c_probe(struct platform_device *pdev) >> gi2c->adap.dev.of_node = pdev->dev.of_node; >> strlcpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name)); >> >> + ret = geni_i2c_icc_get(&gi2c->se); >> + if (ret) >> + return ret; >> + /* >> + * Set the bus quota for core and cpu to a reasonable value for >> + * register access. >> + * Set quota for DDR based on bus speed, assume peak requirement >> + * as twice of avg bw. >> + */ >> + gi2c->se.avg_bw_core = Bps_to_icc(1000); > as commented on the UART patch, you might want to consider adding a constant > for this recurring default value. > >> + gi2c->se.peak_bw_core = Bps_to_icc(CORE_2X_100_MHZ); >> + gi2c->se.avg_bw_cpu = Bps_to_icc(1000); >> + gi2c->se.peak_bw_cpu = Bps_to_icc(1000); >> + gi2c->se.avg_bw_ddr = Bps_to_icc(gi2c->clk_freq_out); >> + gi2c->se.peak_bw_ddr = Bps_to_icc(2 * gi2c->clk_freq_out); >> + >> + /* Vote for core clocks and CPU for register access */ >> + ret = icc_set_bw(gi2c->se.icc_path_geni_to_core, gi2c->se.avg_bw_core, >> + gi2c->se.peak_bw_core); >> + if (ret) { >> + dev_err(&pdev->dev, "%s: ICC BW voting failed for core\n", >> + __func__); >> + return ret; >> + } >> + >> + ret = icc_set_bw(gi2c->se.icc_path_cpu_to_geni, gi2c->se.avg_bw_cpu, >> + gi2c->se.peak_bw_cpu); >> + if (ret) { >> + dev_err(&pdev->dev, "%s: ICC BW voting failed for cpu\n", >> + __func__); >> + return ret; >> + } >> + >> ret = geni_se_resources_on(&gi2c->se); >> if (ret) { >> dev_err(&pdev->dev, "Error turning on resources %d\n", ret); >> @@ -584,6 +634,19 @@ static int geni_i2c_probe(struct platform_device *pdev) >> dev_err(&pdev->dev, "Error turning off resources %d\n", ret); >> return ret; >> } >> + /* Remove vote from core clocks and CPU */ >> + ret = icc_set_bw(gi2c->se.icc_path_geni_to_core, 0, 0); >> + if (ret) { >> + dev_err(&pdev->dev, "%s: ICC BW remove failed for core\n", >> + __func__); >> + return ret; >> + } >> + >> + ret = icc_set_bw(gi2c->se.icc_path_cpu_to_geni, 0, 0); >> + if (ret) { >> + dev_err(&pdev->dev, "%s: ICC BW remove failed for cpu\n", >> + __func__); > Should this return an error as for the core clocks? > >> + } >> >> dev_dbg(&pdev->dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth); >> >> @@ -629,6 +692,28 @@ static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev) >> gi2c->suspended = 1; >> } >> >> + /* Remove BW votes */ >> + ret = icc_set_bw(gi2c->se.icc_path_geni_to_core, 0, 0); >> + if (ret) { >> + dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW remove failed for core\n", >> + __func__); >> + return ret; >> + } >> + >> + ret = icc_set_bw(gi2c->se.icc_path_cpu_to_geni, 0, 0); >> + if (ret) { >> + dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW remove failed for cpu\n", >> + __func__); >> + return ret; >> + } >> + >> + ret = icc_set_bw(gi2c->se.icc_path_geni_to_ddr, 0, 0); >> + if (ret) { >> + dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW remove failed for ddr\n", >> + __func__); >> + return ret; >> + } > you could consider putting this and the ICC voting in _runtime_resume() in > separate functions and call them from here and _probe(). The only difference > in _probe() is that it doesn't vote for the DDR bandwidth, but that slight > one-time overhead might be worth for consolidating the code. > > Actually all this looks very similar for UART, I2C, SPI and QSPI. It seems it > should be possible to consolidate this further by having functions like these > in the geni SE driver: > > int geni_icc_get(struct geni_se *se, const char *icc_core, const char *icc_cpu, > const char *icc_ddr) > { > if (icc_core) { > se->icc_path_geni_to_core = devm_of_icc_get(se->dev, icc_core); > if (IS_ERR(se->icc_path_geni_to_core)) > return PTR_ERR(se->icc_path_geni_to_core); > } > > if (icc_cpu) { > > ... > } > > int geni_icc_vote_on(struct geni_se *se) > { > if (gi2c->se.icc_path_geni_to_core) { > ret = icc_set_bw(gi2c->se.icc_path_geni_to_core, gi2c->se.avg_bw_core, > gi2c->se.peak_bw_core); > if (ret) { > dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW voting failed for core\n", > __func__); > return ret; > } > } > > /* or to reduce nesting: > if (!gi2c->se.icc_path_geni_to_core) > goto vote_cpu; > > ret = icc_set_bw(gi2c->se.icc_path_geni_to_core, gi2c->se.avg_bw_core, > gi2c->se.peak_bw_core); > if (ret) { > ... > > vote_cpu: > */ > > if (gi2c->se.icc_path_cpu_to_geni) { > > ... > } > > int geni_icc_vote_off(struct geni_se *se) > { > if (gi2c->se.icc_path_geni_to_core) { > ret = icc_set_bw(gi2c->se.icc_path_geni_to_core, 0, 0); > if (ret) { > dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW remove failed for core\n", > __func__); > return ret; > } > } > > if (gi2c->se.icc_path_cpu_to_geni) { > > ... > } > > optionally you could even reduce the code further by having an array of > 'struct geni_icc_path' (as suggested on https://patchwork.kernel.org/patch/11436889/#23221925) > and iterate over the array instead of spelling everything out for the 3 > ICC paths. ok >> + >> return 0; >> } >> >> @@ -637,6 +722,31 @@ static int __maybe_unused geni_i2c_runtime_resume(struct device *dev) >> int ret; >> struct geni_i2c_dev *gi2c = dev_get_drvdata(dev); >> >> + /* Vote on Core, CPU and DDR path respectively */ >> + ret = icc_set_bw(gi2c->se.icc_path_geni_to_core, gi2c->se.avg_bw_core, >> + gi2c->se.peak_bw_core); >> + if (ret) { >> + dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW voting failed for core\n", >> + __func__); >> + return ret; >> + } >> + >> + ret = icc_set_bw(gi2c->se.icc_path_cpu_to_geni, gi2c->se.avg_bw_cpu, >> + gi2c->se.peak_bw_cpu); >> + if (ret) { >> + dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW voting failed for cpu\n", >> + __func__); >> + return ret; >> + } >> + >> + ret = icc_set_bw(gi2c->se.icc_path_geni_to_ddr, gi2c->se.avg_bw_ddr, >> + gi2c->se.peak_bw_ddr); >> + if (ret) { >> + dev_err_ratelimited(gi2c->se.dev, "%s: ICC BW voting failed for ddr\n", >> + __func__); >> + return ret; >> + } >> + > as per above this would be just: > > ret = geni_icc_vote_on(&gi2c->se); > if (ret) > return ret; > > with the same benefit for the other 3 drivers. Yeah this would be better. Thanks for reviewing. regards, Akash -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project