From mboxrd@z Thu Jan 1 00:00:00 1970 From: ilia.lin@gmail.com Subject: [PATCH v13 7/8] clk: qcom: cpu-8996: Add support to switch below 600Mhz Date: Thu, 14 Jun 2018 23:53:54 +0200 Message-ID: <20180614215358.11264-8-ilia.lin@gmail.com> References: <20180614215358.11264-1-ilia.lin@gmail.com> Return-path: In-Reply-To: <20180614215358.11264-1-ilia.lin@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: ilia.lin@gmail.com Cc: Rajendra Nayak , Ilia Lin , Michael Turquette , Stephen Boyd , Rob Herring , Mark Rutland , Andy Gross , David Brown , Will Deacon , Amit Kucheria , linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org From: Rajendra Nayak The CPU clock controller's primary PLL operates on a single VCO range, between 600MHz and 3GHz. However the CPUs do support OPPs with frequencies between 300MHz and 600MHz. In order to support running the CPUs at those frequencies we end up having to lock the PLL at twice the rate and drive the CPU clk via the PLL/2 output and SMUX. So for frequencies above 600MHz we follow the following path Primary PLL --> PLL_EARLY --> PMUX(1) --> CPU clk and for frequencies between 300MHz and 600MHz we follow Primary PLL --> PLL/2 --> SMUX(1) --> PMUX(0) --> CPU clk Signed-off-by: Rajendra Nayak Signed-off-by: Ilia Lin Tested-by: Amit Kucheria --- drivers/clk/qcom/clk-cpu-8996.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/clk/qcom/clk-cpu-8996.c b/drivers/clk/qcom/clk-cpu-8996.c index 620fdc2266ba..ff5c0a5740d2 100644 --- a/drivers/clk/qcom/clk-cpu-8996.c +++ b/drivers/clk/qcom/clk-cpu-8996.c @@ -68,6 +68,8 @@ enum _pmux_input { NUM_OF_PMUX_INPUTS }; +#define DIV_2_THRESHOLD 600000000 + static const u8 prim_pll_regs[PLL_OFF_MAX_REGS] = { [PLL_OFF_L_VAL] = 0x04, [PLL_OFF_ALPHA_VAL] = 0x08, @@ -95,10 +97,11 @@ static const u8 alt_pll_regs[PLL_OFF_MAX_REGS] = { static const struct alpha_pll_config hfpll_config = { .l = 60, - .config_ctl_val = 0x200d4828, + .config_ctl_val = 0x200d4aa8, .config_ctl_hi_val = 0x006, .pre_div_mask = BIT(12), .post_div_mask = 0x3 << 8, + .post_div_val = 0x1 << 8, .main_output_mask = BIT(0), .early_output_mask = BIT(3), }; @@ -140,7 +143,7 @@ static const struct alpha_pll_config altpll_config = { .vco_mask = 0x3 << 20, .config_ctl_val = 0x4001051b, .post_div_mask = 0x3 << 8, - .post_div_val = 0x1, + .post_div_val = 0x1 << 8, .main_output_mask = BIT(0), .early_output_mask = BIT(3), }; @@ -181,6 +184,7 @@ struct clk_cpu_8996_mux { u8 width; struct notifier_block nb; struct clk_hw *pll; + struct clk_hw *pll_div_2; struct clk_regmap clkr; }; @@ -226,6 +230,13 @@ clk_cpu_8996_mux_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw); struct clk_hw *parent = cpuclk->pll; + if (cpuclk->pll_div_2 && req->rate < DIV_2_THRESHOLD) { + if (req->rate < (DIV_2_THRESHOLD / 2)) + return -EINVAL; + + parent = cpuclk->pll_div_2; + } + req->best_parent_rate = clk_hw_round_rate(parent, req->rate); req->best_parent_hw = parent; @@ -237,13 +248,19 @@ int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event, { int ret; struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_nb(nb); + struct clk_notifier_data *cnd = data; switch (event) { case PRE_RATE_CHANGE: ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw, ALT_INDEX); break; case POST_RATE_CHANGE: - ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw, PLL_INDEX); + if (cnd->new_rate < DIV_2_THRESHOLD) + ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw, + DIV_2_INDEX); + else + ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw, + PLL_INDEX); break; default: ret = 0; @@ -295,6 +312,7 @@ static struct clk_cpu_8996_mux pwrcl_pmux = { .shift = 0, .width = 2, .pll = &pwrcl_pll.clkr.hw, + .pll_div_2 = &pwrcl_smux.clkr.hw, .nb.notifier_call = cpu_clk_notifier_cb, .clkr.hw.init = &(struct clk_init_data) { .name = "pwrcl_pmux", @@ -315,6 +333,7 @@ static struct clk_cpu_8996_mux perfcl_pmux = { .shift = 0, .width = 2, .pll = &perfcl_pll.clkr.hw, + .pll_div_2 = &perfcl_smux.clkr.hw, .nb.notifier_call = cpu_clk_notifier_cb, .clkr.hw.init = &(struct clk_init_data) { .name = "perfcl_pmux", -- 2.11.0