Re: [PATCH v2 4/4] clk: qcom: lpass: Add support for LPASS clock controller for SC7180

From: Stephen Boyd
Date: Tue May 26 2020 - 23:10:44 EST


Quoting Taniya Das (2020-05-17 02:22:24)
> diff --git a/drivers/clk/qcom/lpasscorecc-sc7180.c b/drivers/clk/qcom/lpasscorecc-sc7180.c
> new file mode 100644
> index 0000000..86e3599
> --- /dev/null
> +++ b/drivers/clk/qcom/lpasscorecc-sc7180.c
> @@ -0,0 +1,479 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2020, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/pm_clock.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +
> +#include <dt-bindings/clock/qcom,lpasscorecc-sc7180.h>
> +
> +#include "clk-alpha-pll.h"
> +#include "clk-branch.h"
> +#include "clk-rcg.h"
> +#include "clk-regmap.h"
> +#include "common.h"
> +#include "gdsc.h"
> +
> +enum {
> + P_BI_TCXO,
> + P_LPASS_LPAAUDIO_DIG_PLL_OUT_ODD,
> + P_SLEEP_CLK,
> +};
> +
> +static struct pll_vco fabia_vco[] = {
> + { 249600000, 2000000000, 0 },
> +};
> +
> +static const struct alpha_pll_config lpass_lpaaudio_dig_pll_config = {
> + .l = 0x20,
[...]
> +
> +static struct regmap_config lpass_core_cc_sc7180_regmap_config = {
> + .reg_bits = 32,
> + .reg_stride = 4,
> + .val_bits = 32,
> + .fast_io = true,
> +};
> +
> +static const struct qcom_cc_desc lpass_core_hm_sc7180_desc = {
> + .config = &lpass_core_cc_sc7180_regmap_config,
> + .gdscs = lpass_core_hm_sc7180_gdscs,
> + .num_gdscs = ARRAY_SIZE(lpass_core_hm_sc7180_gdscs),
> +};
> +
> +static const struct qcom_cc_desc lpass_core_cc_sc7180_desc = {
> + .config = &lpass_core_cc_sc7180_regmap_config,
> + .clks = lpass_core_cc_sc7180_clocks,
> + .num_clks = ARRAY_SIZE(lpass_core_cc_sc7180_clocks),
> +};
> +
> +static const struct qcom_cc_desc lpass_audio_hm_sc7180_desc = {
> + .config = &lpass_core_cc_sc7180_regmap_config,
> + .gdscs = lpass_audio_hm_sc7180_gdscs,
> + .num_gdscs = ARRAY_SIZE(lpass_audio_hm_sc7180_gdscs),
> +};
> +
> +

Drop double newline please.

> +static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
> +{
> + const struct qcom_cc_desc *desc;
> + struct regmap *regmap;
> + int ret;
> +
> + lpass_core_cc_sc7180_regmap_config.name = "lpass_audio_cc";
> + desc = &lpass_audio_hm_sc7180_desc;
> + ret = qcom_cc_probe_by_index(pdev, 1, desc);
> + if (ret)
> + return ret;
> +
> + lpass_core_cc_sc7180_regmap_config.name = "lpass_core_cc";
> + regmap = qcom_cc_map(pdev, &lpass_core_cc_sc7180_desc);
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + /*
> + * Keep the CLK always-ON

Why? Presumably to make sure we can access the lpass sysnoc path all the
time?

> + * LPASS_AUDIO_CORE_SYSNOC_SWAY_CORE_CLK
> + */
> + regmap_update_bits(regmap, 0x24000, BIT(0), BIT(0));
> +
> + /* PLL settings */
> + regmap_write(regmap, 0x1008, 0x20);
> + regmap_update_bits(regmap, 0x1014, BIT(0), BIT(0));
> +
> + clk_fabia_pll_configure(&lpass_lpaaudio_dig_pll, regmap,
> + &lpass_lpaaudio_dig_pll_config);
> +
> + return qcom_cc_really_probe(pdev, &lpass_core_cc_sc7180_desc, regmap);
> +}
> +
> +static int lpass_hm_core_probe(struct platform_device *pdev)
> +{
> + const struct qcom_cc_desc *desc;
> + int ret;
> +
> + lpass_core_cc_sc7180_regmap_config.name = "lpass_hm_core";
> + desc = &lpass_core_hm_sc7180_desc;
> +
> + return qcom_cc_probe_by_index(pdev, 0, desc);
> +}
> +
> +static const struct of_device_id lpass_core_cc_sc7180_match_table[] = {
> + {
> + .compatible = "qcom,sc7180-lpasshm",
> + .data = lpass_hm_core_probe,
> + },
> + {
> + .compatible = "qcom,sc7180-lpasscorecc",
> + .data = lpass_core_cc_sc7180_probe,
> + },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, lpass_core_cc_sc7180_match_table);
> +
> +static int lpass_core_sc7180_probe(struct platform_device *pdev)
> +{
> + int (*clk_probe)(struct platform_device *p);
> + int ret;
> +
> + pm_runtime_enable(&pdev->dev);
> + ret = pm_clk_create(&pdev->dev);
> + if (ret)
> + return ret;
> +
> + ret = pm_clk_add(&pdev->dev, "gcc_lpass_sway");
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to acquire iface clock\n");

Can the clk name be 'iface' if it's actually the interface clk?
"gcc_lpass_sway" looks to be the actual clk name which we shouldn't care
about here. It should be whatever clk name we consider it to be, which
would mean iface probably.

> + goto disable_pm_runtime;
> + }
> +
> + clk_probe = of_device_get_match_data(&pdev->dev);
> + if (!clk_probe)
> + return -EINVAL;
> +
> + ret = clk_probe(pdev);
> + if (ret)
> + goto destroy_pm_clk;
> +
> + return 0;