clk: qcom: Add ipq apss pll driver

The CPUs on Qualcomm ipq based devices are clocked by an alpha PLL.
Add support for the apss pll found on ipq based devices which can
support CPU frequencies above 1Ghz.

Signed-off-by: Sivaprakash Murugesan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Stephen Boyd <[email protected]>

Author: Sivaprakash Murugesan

drivers/clk/qcom/Kconfig

@@ -89,6 +89,14 @@ config APQ_MMCC_8084
 	  Say Y if you want to support multimedia devices such as display,
 	  graphics, video encode/decode, camera, etc.
 
+config IPQ_APSS_PLL
+	tristate "IPQ APSS PLL"
+	help
+	  Support for APSS PLL on ipq devices. The APSS PLL is the main
+	  clock that feeds the CPUs on ipq based devices.
+	  Say Y if you want to support CPU frequency scaling on ipq based
+	  devices.
+
 config IPQ_GCC_4019
 	tristate "IPQ4019 Global Clock Controller"
 	help

drivers/clk/qcom/Makefile

@@ -19,6 +19,7 @@ clk-qcom-$(CONFIG_QCOM_GDSC) += gdsc.o
 # Keep alphabetically sorted by config
 obj-$(CONFIG_APQ_GCC_8084) += gcc-apq8084.o
 obj-$(CONFIG_APQ_MMCC_8084) += mmcc-apq8084.o
+obj-$(CONFIG_IPQ_APSS_PLL) += apss-ipq-pll.o
 obj-$(CONFIG_IPQ_GCC_4019) += gcc-ipq4019.o
 obj-$(CONFIG_IPQ_GCC_6018) += gcc-ipq6018.o
 obj-$(CONFIG_IPQ_GCC_806X) += gcc-ipq806x.o

drivers/clk/qcom/apss-ipq-pll.c

@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018, The Linux Foundation. All rights reserved.
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "clk-alpha-pll.h"
+
+static const u8 ipq_pll_offsets[] = {
+	[PLL_OFF_L_VAL] = 0x08,
+	[PLL_OFF_ALPHA_VAL] = 0x10,
+	[PLL_OFF_USER_CTL] = 0x18,
+	[PLL_OFF_CONFIG_CTL] = 0x20,
+	[PLL_OFF_CONFIG_CTL_U] = 0x24,
+	[PLL_OFF_STATUS] = 0x28,
+	[PLL_OFF_TEST_CTL] = 0x30,
+	[PLL_OFF_TEST_CTL_U] = 0x34,
+};
+
+static struct clk_alpha_pll ipq_pll = {
+	.offset = 0x0,
+	.regs = ipq_pll_offsets,
+	.flags = SUPPORTS_DYNAMIC_UPDATE,
+	.clkr = {
+		.enable_reg = 0x0,
+		.enable_mask = BIT(0),
+		.hw.init = &(struct clk_init_data){
+			.name = "a53pll",
+			.parent_data = &(const struct clk_parent_data) {
+				.fw_name = "xo",
+			},
+			.num_parents = 1,
+			.ops = &clk_alpha_pll_huayra_ops,
+		},
+	},
+};
+
+static const struct alpha_pll_config ipq_pll_config = {
+	.l = 0x37,
+	.config_ctl_val = 0x04141200,
+	.config_ctl_hi_val = 0x0,
+	.early_output_mask = BIT(3),
+	.main_output_mask = BIT(0),
+};
+
+static const struct regmap_config ipq_pll_regmap_config = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= 0x40,
+	.fast_io		= true,
+};
+
+static int apss_ipq_pll_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regmap *regmap;
+	void __iomem *base;
+	int ret;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(dev, base, &ipq_pll_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	clk_alpha_pll_configure(&ipq_pll, regmap, &ipq_pll_config);
+
+	ret = devm_clk_register_regmap(dev, &ipq_pll.clkr);
+	if (ret)
+		return ret;
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+					   &ipq_pll.clkr.hw);
+}
+
+static const struct of_device_id apss_ipq_pll_match_table[] = {
+	{ .compatible = "qcom,ipq6018-a53pll" },
+	{ }
+};
+
+static struct platform_driver apss_ipq_pll_driver = {
+	.probe = apss_ipq_pll_probe,
+	.driver = {
+		.name = "qcom-ipq-apss-pll",
+		.of_match_table = apss_ipq_pll_match_table,
+	},
+};
+module_platform_driver(apss_ipq_pll_driver);
+
+MODULE_DESCRIPTION("Qualcomm technology Inc APSS ALPHA PLL Driver");
+MODULE_LICENSE("GPL v2");