clk: qcom: Add A53 PLL support

The CPUs on Qualcomm MSM8916-based platforms are clocked by two PLLs,
a primary (A53) CPU PLL and a secondary fixed-rate GPLL0. These sources
are connected to a mux and half-integer divider, which is feeding the
CPU cores.

This patch adds support for the primary CPU PLL which generates the
higher range of frequencies above 1GHz.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
[sboyd@codeaurora.org: Move to devm provider registration,
NUL terminate frequency table, made tristate/modular]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

4 files changed, 140 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/qcom,a53pll.txt b/Documentation/devicetree/bindings/clock/qcom,a53pll.txt
new file mode 100644
index 000000000000..e3fa8118eaee
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/qcom,a53pll.txt
@@ -0,0 +1,22 @@
+Qualcomm MSM8916 A53 PLL Binding
+--------------------------------
+The A53 PLL on MSM8916 platforms is the main CPU PLL used used for frequencies
+above 1GHz.
+
+Required properties :
+- compatible : Shall contain only one of the following:
+
+                "qcom,msm8916-a53pll"
+
+- reg : shall contain base register location and length
+
+- #clock-cells : must be set to <0>
+
+Example:
+
+        a53pll: clock@b016000 {
+                compatible = "qcom,msm8916-a53pll";
+                reg = <0xb016000 0x40>;
+                #clock-cells = <0>;
+        };
+
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 9f6c278deead..49db9fda6548 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -12,6 +12,16 @@ config COMMON_CLK_QCOM
         select REGMAP_MMIO
         select RESET_CONTROLLER
 
+config QCOM_A53PLL
+        tristate "MSM8916 A53 PLL"
+        depends on COMMON_CLK_QCOM
+        default ARCH_QCOM
+        help
+          Support for the A53 PLL on MSM8916 devices. It provides
+          the CPU with frequencies above 1GHz.
+          Say Y if you want to support higher CPU frequencies on MSM8916
+          devices.
+
 config QCOM_CLK_RPM
         tristate "RPM based Clock Controller"
         depends on COMMON_CLK_QCOM && MFD_QCOM_RPM
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 26410d31446b..e767c60c24ec 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -32,5 +32,6 @@ obj-$(CONFIG_MSM_LCC_8960) += lcc-msm8960.o
 obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
 obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
 obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
+obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
 obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
 obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
diff --git a/drivers/clk/qcom/a53-pll.c b/drivers/clk/qcom/a53-pll.c
new file mode 100644
index 000000000000..45cfc57bff92
--- /dev/null
+++ b/drivers/clk/qcom/a53-pll.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Qualcomm A53 PLL driver
+ *
+ * Copyright (c) 2017, Linaro Limited
+ * Author: Georgi Djakov <georgi.djakov@linaro.org>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/module.h>
+
+#include "clk-pll.h"
+#include "clk-regmap.h"
+
+static const struct pll_freq_tbl a53pll_freq[] = {
+        {  998400000, 52, 0x0, 0x1, 0 },
+        { 1094400000, 57, 0x0, 0x1, 0 },
+        { 1152000000, 62, 0x0, 0x1, 0 },
+        { 1209600000, 63, 0x0, 0x1, 0 },
+        { 1248000000, 65, 0x0, 0x1, 0 },
+        { 1363200000, 71, 0x0, 0x1, 0 },
+        { 1401600000, 73, 0x0, 0x1, 0 },
+        { }
+};
+
+static const struct regmap_config a53pll_regmap_config = {
+        .reg_bits               = 32,
+        .reg_stride             = 4,
+        .val_bits               = 32,
+        .max_register           = 0x40,
+        .fast_io                = true,
+};
+
+static int qcom_a53pll_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct regmap *regmap;
+        struct resource *res;
+        struct clk_pll *pll;
+        void __iomem *base;
+        struct clk_init_data init = { };
+        int ret;
+
+        pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
+        if (!pll)
+                return -ENOMEM;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        base = devm_ioremap_resource(dev, res);
+        if (IS_ERR(base))
+                return PTR_ERR(base);
+
+        regmap = devm_regmap_init_mmio(dev, base, &a53pll_regmap_config);
+        if (IS_ERR(regmap))
+                return PTR_ERR(regmap);
+
+        pll->l_reg = 0x04;
+        pll->m_reg = 0x08;
+        pll->n_reg = 0x0c;
+        pll->config_reg = 0x14;
+        pll->mode_reg = 0x00;
+        pll->status_reg = 0x1c;
+        pll->status_bit = 16;
+        pll->freq_tbl = a53pll_freq;
+
+        init.name = "a53pll";
+        init.parent_names = (const char *[]){ "xo" };
+        init.num_parents = 1;
+        init.ops = &clk_pll_sr2_ops;
+        init.flags = CLK_IS_CRITICAL;
+        pll->clkr.hw.init = &init;
+
+        ret = devm_clk_register_regmap(dev, &pll->clkr);
+        if (ret) {
+                dev_err(dev, "failed to register regmap clock: %d\n", ret);
+                return ret;
+        }
+
+        ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+                                          &pll->clkr.hw);
+        if (ret) {
+                dev_err(dev, "failed to add clock provider: %d\n", ret);
+                return ret;
+        }
+
+        return 0;
+}
+
+static const struct of_device_id qcom_a53pll_match_table[] = {
+        { .compatible = "qcom,msm8916-a53pll" },
+        { }
+};
+
+static struct platform_driver qcom_a53pll_driver = {
+        .probe = qcom_a53pll_probe,
+        .driver = {
+                .name = "qcom-a53pll",
+                .of_match_table = qcom_a53pll_match_table,
+        },
+};
+module_platform_driver(qcom_a53pll_driver);
+
+MODULE_DESCRIPTION("Qualcomm A53 PLL Driver");
+MODULE_LICENSE("GPL v2");