From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Lo Subject: Re: [PATCH V2 07/21] clk: tegra: dfll: support PWM regulator control Date: Fri, 14 Dec 2018 15:11:28 +0800 Message-ID: References: <20181213093438.29621-1-josephl@nvidia.com> <20181213093438.29621-8-josephl@nvidia.com> <42e5746b-8484-8c2d-f871-5ad17e576f32@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <42e5746b-8484-8c2d-f871-5ad17e576f32@nvidia.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Jon Hunter , Thierry Reding , Peter De Schrijver Cc: linux-tegra@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-tegra@vger.kernel.org On 12/13/18 7:41 PM, Jon Hunter wrote: > > On 13/12/2018 09:34, Joseph Lo wrote: >> The DFLL hardware supports two modes (I2C and PWM) for voltage control >> when requesting a frequency. In this patch, we introduce PWM mode support. >> >> To support that, we re-organize the LUT for unifying the table for both >> cases of I2C and PWM mode. And generate that based on regulator info. >> For the PWM-based regulator, we get this info from DT. And do the same as >> the case of I2C LUT, which can help to map the PMIC voltage ID and voltages >> that the regulator supported. >> >> The other parts are the support code for initializing the DFLL hardware >> to support PWM mode. Also, the register debugfs file is slightly >> reworked to only show the i2c registers when I2C mode is in use. >> >> Based on the work of Peter De Schrijver . >> >> Signed-off-by: Joseph Lo >> --- >> *V2: >> - move reg_init_uV to be with the PWM related variables >> - fix the variable type to 'unsigned long' if it needs to catch the >> return value from 'dev_pm_opp_get_voltage' >> - update to use lut_uv table for LUT look up. This makes the generic >> lut_uv table to work with both PWM and I2C mode. >> --- >> drivers/clk/tegra/clk-dfll.c | 435 +++++++++++++++++++++++++++++------ >> 1 file changed, 369 insertions(+), 66 deletions(-) snip. >> @@ -594,24 +750,41 @@ static void dfll_init_out_if(struct tegra_dfll *td) >> { >> u32 val; >> >> - td->lut_min = 0; >> - td->lut_max = td->i2c_lut_size - 1; >> - td->lut_safe = td->lut_min + 1; >> + td->lut_min = td->lut_bottom; >> + td->lut_max = td->lut_size - 1; >> + td->lut_safe = td->lut_min + (td->lut_min < td->lut_max ? 1 : 0); >> + >> + /* clear DFLL_OUTPUT_CFG before setting new value */ >> + dfll_writel(td, 0, DFLL_OUTPUT_CFG); >> + dfll_wmb(td); >> >> - dfll_i2c_writel(td, 0, DFLL_OUTPUT_CFG); >> val = (td->lut_safe << DFLL_OUTPUT_CFG_SAFE_SHIFT) | >> - (td->lut_max << DFLL_OUTPUT_CFG_MAX_SHIFT) | >> - (td->lut_min << DFLL_OUTPUT_CFG_MIN_SHIFT); >> - dfll_i2c_writel(td, val, DFLL_OUTPUT_CFG); >> - dfll_i2c_wmb(td); >> + (td->lut_max << DFLL_OUTPUT_CFG_MAX_SHIFT) | >> + (td->lut_min << DFLL_OUTPUT_CFG_MIN_SHIFT); >> + dfll_writel(td, val, DFLL_OUTPUT_CFG); >> + dfll_wmb(td); >> >> dfll_writel(td, 0, DFLL_OUTPUT_FORCE); >> dfll_i2c_writel(td, 0, DFLL_INTR_EN); >> dfll_i2c_writel(td, DFLL_INTR_MAX_MASK | DFLL_INTR_MIN_MASK, >> DFLL_INTR_STS); >> >> - dfll_load_i2c_lut(td); >> - dfll_init_i2c_if(td); >> + if (td->pmu_if == TEGRA_DFLL_PMU_PWM) { >> + int vinit = td->reg_init_uV; > > This should be u32. > >> + int vstep = td->soc->alignment.step_uv; >> + int vmin = td->lut_uv[0]; > > This should be unsigned long. > >> + >> + /* set initial voltage */ >> + if ((vinit >= vmin) && vstep) { >> + unsigned int vsel; >> + >> + vsel = DIV_ROUND_UP((vinit - vmin), vstep); >> + dfll_force_output(td, vsel); >> + } >> + } else { >> + dfll_load_i2c_lut(td); >> + dfll_init_i2c_if(td); >> + } >> } >> >> /* >> @@ -640,8 +813,8 @@ static int find_lut_index_for_rate(struct tegra_dfll *td, unsigned long rate) >> uv = dev_pm_opp_get_voltage(opp); >> dev_pm_opp_put(opp); >> >> - for (i = 0; i < td->i2c_lut_size; i++) { >> - if (regulator_list_voltage(td->vdd_reg, td->i2c_lut[i]) == uv) >> + for (i = td->lut_bottom; i < td->lut_size; i++) { >> + if (td->lut_uv[i] >= uv) > > I think that we need to fix the type for 'uv' in this function while we > are at it. Okay, looks like I still have some variable type issue in V2. Will fix accordingly. Thanks, Joseph > > Cheers > Jon >