Message-ID: <20241220-qcom_ipq_cmnpll-v7-2-438a1b5cb98e@quicinc.com>
Date: Fri, 20 Dec 2024 21:22:43 +0800
From: Luo Jie <quic_luoj@...cinc.com>
To: Bjorn Andersson <andersson@...nel.org>,
        Michael Turquette
	<mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, Rob Herring
	<robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley
	<conor+dt@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon
	<will@...nel.org>, Konrad Dybcio <konradybcio@...nel.org>
CC: <linux-arm-msm@...r.kernel.org>, <linux-clk@...r.kernel.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>, <quic_kkumarcs@...cinc.com>,
        <quic_suruchia@...cinc.com>, <quic_pavir@...cinc.com>,
        <quic_linchen@...cinc.com>, <quic_leiwei@...cinc.com>,
        <bartosz.golaszewski@...aro.org>, <srinivas.kandagatla@...aro.org>,
        Luo Jie
	<quic_luoj@...cinc.com>
Subject: [PATCH v7 2/5] clk: qcom: Add CMN PLL clock controller driver for
 IPQ SoC

The CMN PLL clock controller supplies clocks to the hardware
blocks that together make up the Ethernet function on Qualcomm
IPQ SoCs and to GCC. The driver is initially supported for
IPQ9574 SoC.

The CMN PLL clock controller expects a reference input clock
from the on-board Wi-Fi block acting as clock source. The input
reference clock needs to be configured to one of the supported
clock rates.

The controller supplies a number of fixed-rate output clocks.
For the IPQ9574, there is one output clock of 353 MHZ to PPE
(Packet Process Engine) hardware block, three 50 MHZ output
clocks and an additional 25 MHZ output clock supplied to the
connected Ethernet devices. The PLL also supplies a 24 MHZ
clock as XO and a 32 KHZ sleep clock to GCC, and one 31.25
MHZ clock to PCS.

Signed-off-by: Luo Jie <quic_luoj@...cinc.com>
---
 drivers/clk/qcom/Kconfig       |   9 +
 drivers/clk/qcom/Makefile      |   1 +
 drivers/clk/qcom/ipq-cmn-pll.c | 435 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 445 insertions(+)

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index ef89d686cbc4..9d05887cfc6f 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -190,6 +190,15 @@ config IPQ_APSS_6018
 	  Say Y if you want to support CPU frequency scaling on
 	  ipq based devices.
 
+config IPQ_CMN_PLL
+	tristate "IPQ CMN PLL Clock Controller"
+	help
+	  Support for CMN PLL clock controller on IPQ platform. The
+	  CMN PLL consumes the AHB/SYS clocks from GCC and supplies
+	  the output clocks to the networking hardware and GCC blocks.
+	  Say Y or M if you want to support CMN PLL clock on the IPQ
+	  based devices.
+
 config IPQ_GCC_4019
 	tristate "IPQ4019 Global Clock Controller"
 	help
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index b09dbdc210eb..e0ac75b79f84 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_CLK_X1E80100_TCSRCC) += tcsrcc-x1e80100.o
 obj-$(CONFIG_CLK_QCM2290_GPUCC) += gpucc-qcm2290.o
 obj-$(CONFIG_IPQ_APSS_PLL) += apss-ipq-pll.o
 obj-$(CONFIG_IPQ_APSS_6018) += apss-ipq6018.o
+obj-$(CONFIG_IPQ_CMN_PLL) += ipq-cmn-pll.o
 obj-$(CONFIG_IPQ_GCC_4019) += gcc-ipq4019.o
 obj-$(CONFIG_IPQ_GCC_5018) += gcc-ipq5018.o
 obj-$(CONFIG_IPQ_GCC_5332) += gcc-ipq5332.o
diff --git a/drivers/clk/qcom/ipq-cmn-pll.c b/drivers/clk/qcom/ipq-cmn-pll.c
new file mode 100644
index 000000000000..432d4c4b7aa6
--- /dev/null
+++ b/drivers/clk/qcom/ipq-cmn-pll.c
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+/*
+ * CMN PLL block expects the reference clock from on-board Wi-Fi block,
+ * and supplies fixed rate clocks as output to the networking hardware
+ * blocks and to GCC. The networking related blocks include PPE (packet
+ * process engine), the externally connected PHY or switch devices, and
+ * the PCS.
+ *
+ * On the IPQ9574 SoC, there are three clocks with 50 MHZ and one clock
+ * with 25 MHZ which are output from the CMN PLL to Ethernet PHY (or switch),
+ * and one clock with 353 MHZ to PPE. The other fixed rate output clocks
+ * are supplied to GCC (24 MHZ as XO and 32 KHZ as sleep clock), and to PCS
+ * with 31.25 MHZ.
+ *
+ *               +---------+
+ *               |   GCC   |
+ *               +--+---+--+
+ *           AHB CLK|   |SYS CLK
+ *                  V   V
+ *          +-------+---+------+
+ *          |                  +-------------> eth0-50mhz
+ * REF CLK  |     IPQ9574      |
+ * -------->+                  +-------------> eth1-50mhz
+ *          |  CMN PLL block   |
+ *          |                  +-------------> eth2-50mhz
+ *          |                  |
+ *          +----+----+----+---+-------------> eth-25mhz
+ *               |    |    |
+ *               V    V    V
+ *              GCC  PCS  NSS/PPE
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_clock.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include <dt-bindings/clock/qcom,ipq-cmn-pll.h>
+
+#define CMN_PLL_REFCLK_SRC_SELECTION		0x28
+#define CMN_PLL_REFCLK_SRC_DIV			GENMASK(9, 8)
+
+#define CMN_PLL_LOCKED				0x64
+#define CMN_PLL_CLKS_LOCKED			BIT(8)
+
+#define CMN_PLL_POWER_ON_AND_RESET		0x780
+#define CMN_ANA_EN_SW_RSTN			BIT(6)
+
+#define CMN_PLL_REFCLK_CONFIG			0x784
+#define CMN_PLL_REFCLK_EXTERNAL			BIT(9)
+#define CMN_PLL_REFCLK_DIV			GENMASK(8, 4)
+#define CMN_PLL_REFCLK_INDEX			GENMASK(3, 0)
+
+#define CMN_PLL_CTRL				0x78c
+#define CMN_PLL_CTRL_LOCK_DETECT_EN		BIT(15)
+
+#define CMN_PLL_DIVIDER_CTRL			0x794
+#define CMN_PLL_DIVIDER_CTRL_FACTOR		GENMASK(9, 0)
+
+/**
+ * struct cmn_pll_fixed_output_clk - CMN PLL output clocks information
+ * @id:	Clock specifier to be supplied
+ * @name: Clock name to be registered
+ * @rate: Clock rate
+ */
+struct cmn_pll_fixed_output_clk {
+	unsigned int id;
+	const char *name;
+	unsigned long rate;
+};
+
+/**
+ * struct clk_cmn_pll - CMN PLL hardware specific data
+ * @regmap: hardware regmap.
+ * @hw: handle between common and hardware-specific interfaces
+ */
+struct clk_cmn_pll {
+	struct regmap *regmap;
+	struct clk_hw hw;
+};
+
+#define CLK_PLL_OUTPUT(_id, _name, _rate) {		\
+	.id =		_id,				\
+	.name =		_name,				\
+	.rate =		_rate,				\
+}
+
+#define to_clk_cmn_pll(_hw) container_of(_hw, struct clk_cmn_pll, hw)
+
+static const struct regmap_config ipq_cmn_pll_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0x7fc,
+	.fast_io = true,
+};
+
+static const struct cmn_pll_fixed_output_clk ipq9574_output_clks[] = {
+	CLK_PLL_OUTPUT(XO_24MHZ_CLK, "xo-24mhz", 24000000UL),
+	CLK_PLL_OUTPUT(SLEEP_32KHZ_CLK, "sleep-32khz", 32000UL),
+	CLK_PLL_OUTPUT(PCS_31P25MHZ_CLK, "pcs-31p25mhz", 31250000UL),
+	CLK_PLL_OUTPUT(NSS_1200MHZ_CLK, "nss-1200mhz", 1200000000UL),
+	CLK_PLL_OUTPUT(PPE_353MHZ_CLK, "ppe-353mhz", 353000000UL),
+	CLK_PLL_OUTPUT(ETH0_50MHZ_CLK, "eth0-50mhz", 50000000UL),
+	CLK_PLL_OUTPUT(ETH1_50MHZ_CLK, "eth1-50mhz", 50000000UL),
+	CLK_PLL_OUTPUT(ETH2_50MHZ_CLK, "eth2-50mhz", 50000000UL),
+	CLK_PLL_OUTPUT(ETH_25MHZ_CLK, "eth-25mhz", 25000000UL),
+};
+
+/*
+ * CMN PLL has the single parent clock, which supports the several
+ * possible parent clock rates, each parent clock rate is reflected
+ * by the specific reference index value in the hardware.
+ */
+static int ipq_cmn_pll_find_freq_index(unsigned long parent_rate)
+{
+	int index = -EINVAL;
+
+	switch (parent_rate) {
+	case 25000000:
+		index = 3;
+		break;
+	case 31250000:
+		index = 4;
+		break;
+	case 40000000:
+		index = 6;
+		break;
+	case 48000000:
+	case 96000000:
+		/*
+		 * Parent clock rate 48 MHZ and 96 MHZ take the same value
+		 * of reference clock index. 96 MHZ needs the source clock
+		 * divider to be programmed as 2.
+		 */
+		index = 7;
+		break;
+	case 50000000:
+		index = 8;
+		break;
+	default:
+		break;
+	}
+
+	return index;
+}
+
+static unsigned long clk_cmn_pll_recalc_rate(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	struct clk_cmn_pll *cmn_pll = to_clk_cmn_pll(hw);
+	u32 val, factor;
+
+	/*
+	 * The value of CMN_PLL_DIVIDER_CTRL_FACTOR is automatically adjusted
+	 * by HW according to the parent clock rate.
+	 */
+	regmap_read(cmn_pll->regmap, CMN_PLL_DIVIDER_CTRL, &val);
+	factor = FIELD_GET(CMN_PLL_DIVIDER_CTRL_FACTOR, val);
+
+	return parent_rate * 2 * factor;
+}
+
+static int clk_cmn_pll_determine_rate(struct clk_hw *hw,
+				      struct clk_rate_request *req)
+{
+	int ret;
+
+	/* Validate the rate of the single parent clock. */
+	ret = ipq_cmn_pll_find_freq_index(req->best_parent_rate);
+
+	return ret < 0 ? ret : 0;
+}
+
+/*
+ * This function is used to initialize the CMN PLL to enable the fixed
+ * rate output clocks. It is expected to be configured once.
+ */
+static int clk_cmn_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct clk_cmn_pll *cmn_pll = to_clk_cmn_pll(hw);
+	int ret, index;
+	u32 val;
+
+	/*
+	 * Configure the reference input clock selection as per the given
+	 * parent clock. The output clock rates are always of fixed value.
+	 */
+	index = ipq_cmn_pll_find_freq_index(parent_rate);
+	if (index < 0)
+		return index;
+
+	ret = regmap_update_bits(cmn_pll->regmap, CMN_PLL_REFCLK_CONFIG,
+				 CMN_PLL_REFCLK_INDEX,
+				 FIELD_PREP(CMN_PLL_REFCLK_INDEX, index));
+	if (ret)
+		return ret;
+
+	/*
+	 * Update the source clock rate selection and source clock
+	 * divider as 2 when the parent clock rate is 96 MHZ.
+	 */
+	if (parent_rate == 96000000) {
+		ret = regmap_update_bits(cmn_pll->regmap, CMN_PLL_REFCLK_CONFIG,
+					 CMN_PLL_REFCLK_DIV,
+					 FIELD_PREP(CMN_PLL_REFCLK_DIV, 2));
+		if (ret)
+			return ret;
+
+		ret = regmap_update_bits(cmn_pll->regmap, CMN_PLL_REFCLK_SRC_SELECTION,
+					 CMN_PLL_REFCLK_SRC_DIV,
+					 FIELD_PREP(CMN_PLL_REFCLK_SRC_DIV, 0));
+		if (ret)
+			return ret;
+	}
+
+	/* Enable PLL locked detect. */
+	ret = regmap_set_bits(cmn_pll->regmap, CMN_PLL_CTRL,
+			      CMN_PLL_CTRL_LOCK_DETECT_EN);
+	if (ret)
+		return ret;
+
+	/*
+	 * Reset the CMN PLL block to ensure the updated configurations
+	 * take effect.
+	 */
+	ret = regmap_clear_bits(cmn_pll->regmap, CMN_PLL_POWER_ON_AND_RESET,
+				CMN_ANA_EN_SW_RSTN);
+	if (ret)
+		return ret;
+
+	usleep_range(1000, 1200);
+	ret = regmap_set_bits(cmn_pll->regmap, CMN_PLL_POWER_ON_AND_RESET,
+			      CMN_ANA_EN_SW_RSTN);
+	if (ret)
+		return ret;
+
+	/* Stability check of CMN PLL output clocks. */
+	return regmap_read_poll_timeout(cmn_pll->regmap, CMN_PLL_LOCKED, val,
+					(val & CMN_PLL_CLKS_LOCKED),
+					100, 100 * USEC_PER_MSEC);
+}
+
+static const struct clk_ops clk_cmn_pll_ops = {
+	.recalc_rate = clk_cmn_pll_recalc_rate,
+	.determine_rate = clk_cmn_pll_determine_rate,
+	.set_rate = clk_cmn_pll_set_rate,
+};
+
+static struct clk_hw *ipq_cmn_pll_clk_hw_register(struct platform_device *pdev)
+{
+	struct clk_parent_data pdata = { .index = 0 };
+	struct device *dev = &pdev->dev;
+	struct clk_init_data init = {};
+	struct clk_cmn_pll *cmn_pll;
+	struct regmap *regmap;
+	void __iomem *base;
+	int ret;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return ERR_CAST(base);
+
+	regmap = devm_regmap_init_mmio(dev, base, &ipq_cmn_pll_regmap_config);
+	if (IS_ERR(regmap))
+		return ERR_CAST(regmap);
+
+	cmn_pll = devm_kzalloc(dev, sizeof(*cmn_pll), GFP_KERNEL);
+	if (!cmn_pll)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = "cmn_pll";
+	init.parent_data = &pdata;
+	init.num_parents = 1;
+	init.ops = &clk_cmn_pll_ops;
+
+	cmn_pll->hw.init = &init;
+	cmn_pll->regmap = regmap;
+
+	ret = devm_clk_hw_register(dev, &cmn_pll->hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &cmn_pll->hw;
+}
+
+static int ipq_cmn_pll_register_clks(struct platform_device *pdev)
+{
+	const struct cmn_pll_fixed_output_clk *fixed_clk;
+	struct clk_hw_onecell_data *hw_data;
+	struct device *dev = &pdev->dev;
+	struct clk_hw *cmn_pll_hw;
+	unsigned int num_clks;
+	struct clk_hw *hw;
+	int ret, i;
+
+	fixed_clk = ipq9574_output_clks;
+	num_clks = ARRAY_SIZE(ipq9574_output_clks);
+
+	hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, num_clks + 1),
+			       GFP_KERNEL);
+	if (!hw_data)
+		return -ENOMEM;
+
+	/*
+	 * Register the CMN PLL clock, which is the parent clock of
+	 * the fixed rate output clocks.
+	 */
+	cmn_pll_hw = ipq_cmn_pll_clk_hw_register(pdev);
+	if (IS_ERR(cmn_pll_hw))
+		return PTR_ERR(cmn_pll_hw);
+
+	/* Register the fixed rate output clocks. */
+	for (i = 0; i < num_clks; i++) {
+		hw = clk_hw_register_fixed_rate_parent_hw(dev, fixed_clk[i].name,
+							  cmn_pll_hw, 0,
+							  fixed_clk[i].rate);
+		if (IS_ERR(hw)) {
+			ret = PTR_ERR(hw);
+			goto unregister_fixed_clk;
+		}
+
+		hw_data->hws[fixed_clk[i].id] = hw;
+	}
+
+	/*
+	 * Provide the CMN PLL clock. The clock rate of CMN PLL
+	 * is configured to 12 GHZ by DT property assigned-clock-rates-u64.
+	 */
+	hw_data->hws[CMN_PLL_CLK] = cmn_pll_hw;
+	hw_data->num = num_clks + 1;
+
+	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_data);
+	if (ret)
+		goto unregister_fixed_clk;
+
+	platform_set_drvdata(pdev, hw_data);
+
+	return 0;
+
+unregister_fixed_clk:
+	while (i > 0)
+		clk_hw_unregister(hw_data->hws[fixed_clk[--i].id]);
+
+	return ret;
+}
+
+static int ipq_cmn_pll_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return ret;
+
+	ret = devm_pm_clk_create(dev);
+	if (ret)
+		return ret;
+
+	/*
+	 * To access the CMN PLL registers, the GCC AHB & SYS clocks
+	 * of CMN PLL block need to be enabled.
+	 */
+	ret = pm_clk_add(dev, "ahb");
+	if (ret)
+		return dev_err_probe(dev, ret, "Fail to add AHB clock\n");
+
+	ret = pm_clk_add(dev, "sys");
+	if (ret)
+		return dev_err_probe(dev, ret, "Fail to add SYS clock\n");
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	/* Register CMN PLL clock and fixed rate output clocks. */
+	ret = ipq_cmn_pll_register_clks(pdev);
+	pm_runtime_put(dev);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Fail to register CMN PLL clocks\n");
+
+	return 0;
+}
+
+static void ipq_cmn_pll_clk_remove(struct platform_device *pdev)
+{
+	struct clk_hw_onecell_data *hw_data = platform_get_drvdata(pdev);
+	int i;
+
+	/*
+	 * The clock with index CMN_PLL_CLK is unregistered by
+	 * device management.
+	 */
+	for (i = 0; i < hw_data->num; i++) {
+		if (i != CMN_PLL_CLK)
+			clk_hw_unregister(hw_data->hws[i]);
+	}
+}
+
+static const struct dev_pm_ops ipq_cmn_pll_pm_ops = {
+	SET_RUNTIME_PM_OPS(pm_clk_suspend, pm_clk_resume, NULL)
+};
+
+static const struct of_device_id ipq_cmn_pll_clk_ids[] = {
+	{ .compatible = "qcom,ipq9574-cmn-pll", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ipq_cmn_pll_clk_ids);
+
+static struct platform_driver ipq_cmn_pll_clk_driver = {
+	.probe = ipq_cmn_pll_clk_probe,
+	.remove = ipq_cmn_pll_clk_remove,
+	.driver = {
+		.name = "ipq_cmn_pll",
+		.of_match_table = ipq_cmn_pll_clk_ids,
+		.pm = &ipq_cmn_pll_pm_ops,
+	},
+};
+module_platform_driver(ipq_cmn_pll_clk_driver);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. IPQ CMN PLL Driver");
+MODULE_LICENSE("GPL");

-- 
2.34.1

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