clk: qcom: Add A7 PLL support

Add support for PLL found in Qualcomm SDX55 platforms which is used to provide
clock to the Cortex A7 CPU via a mux. This PLL can provide high frequency clock
to the CPU above 1GHz as compared to the other sources like GPLL0.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

3 files changed, 109 insertions, 0 deletions

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index d32bb12cd8d0..d6f4aee4427a 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -28,6 +28,14 @@ config QCOM_A53PLL
 	  Say Y if you want to support higher CPU frequencies on MSM8916
 	  devices.
 
+config QCOM_A7PLL
+	tristate "SDX55 A7 PLL"
+	help
+	  Support for the A7 PLL on SDX55 devices. It provides the CPU with
+	  frequencies above 1GHz.
+	  Say Y if you want to support higher CPU frequencies on SDX55
+	  devices.
+
 config QCOM_CLK_APCS_MSM8916
 	tristate "MSM8916 APCS Clock Controller"
 	depends on QCOM_APCS_IPC || COMPILE_TEST
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 9e5e0e3cb7b4..e7e0ac382176 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
 obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
 obj-$(CONFIG_MSM_MMCC_8998) += mmcc-msm8998.o
 obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
+obj-$(CONFIG_QCOM_A7PLL) += a7-pll.o
 obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
 obj-$(CONFIG_QCOM_CLK_APCC_MSM8996) += clk-cpu-8996.o
 obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
diff --git a/drivers/clk/qcom/a7-pll.c b/drivers/clk/qcom/a7-pll.c
new file mode 100644
index 000000000000..e171d3caf2cf
--- /dev/null
+++ b/drivers/clk/qcom/a7-pll.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Qualcomm A7 PLL driver
+ *
+ * Copyright (c) 2020, Linaro Limited
+ * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "clk-alpha-pll.h"
+
+#define LUCID_PLL_OFF_L_VAL 0x04
+
+static const struct pll_vco lucid_vco[] = {
+	{ 249600000, 2000000000, 0 },
+};
+
+static struct clk_alpha_pll a7pll = {
+	.offset = 0x100,
+	.vco_table = lucid_vco,
+	.num_vco = ARRAY_SIZE(lucid_vco),
+	.regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_LUCID],
+	.clkr = {
+		.hw.init = &(struct clk_init_data){
+			.name = "a7pll",
+			.parent_data =  &(const struct clk_parent_data){
+				.fw_name = "bi_tcxo",
+			},
+			.num_parents = 1,
+			.ops = &clk_alpha_pll_lucid_ops,
+		},
+	},
+};
+
+static const struct alpha_pll_config a7pll_config = {
+	.l = 0x39,
+	.config_ctl_val = 0x20485699,
+	.config_ctl_hi_val = 0x2261,
+	.config_ctl_hi1_val = 0x029A699C,
+	.user_ctl_val = 0x1,
+	.user_ctl_hi_val = 0x805,
+};
+
+static const struct regmap_config a7pll_regmap_config = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= 0x1000,
+	.fast_io		= true,
+};
+
+static int qcom_a7pll_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regmap *regmap;
+	void __iomem *base;
+	u32 l_val;
+	int ret;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(dev, base, &a7pll_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	/* Configure PLL only if the l_val is zero */
+	regmap_read(regmap, a7pll.offset + LUCID_PLL_OFF_L_VAL, &l_val);
+	if (!l_val)
+		clk_lucid_pll_configure(&a7pll, regmap, &a7pll_config);
+
+	ret = devm_clk_register_regmap(dev, &a7pll.clkr);
+	if (ret)
+		return ret;
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+					   &a7pll.clkr.hw);
+}
+
+static const struct of_device_id qcom_a7pll_match_table[] = {
+	{ .compatible = "qcom,sdx55-a7pll" },
+	{ }
+};
+
+static struct platform_driver qcom_a7pll_driver = {
+	.probe = qcom_a7pll_probe,
+	.driver = {
+		.name = "qcom-a7pll",
+		.of_match_table = qcom_a7pll_match_table,
+	},
+};
+module_platform_driver(qcom_a7pll_driver);
+
+MODULE_DESCRIPTION("Qualcomm A7 PLL Driver");
+MODULE_LICENSE("GPL v2");