[PATCH v3 11/13] clk: qcom: Add Krait clock controller driver

Stephen Boyd
2015-03-21T06:46:13Z

The Krait CPU clocks are made up of a primary mux and secondary
mux for each CPU and the L2, controlled via cp15 accessors. For
Kraits within KPSSv1 each secondary mux accepts a different aux
source, but on KPSSv2 each secondary mux accepts the same aux
source.

Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
.../devicetree/bindings/clock/qcom,krait-cc.txt | 22 ++
drivers/clk/qcom/Kconfig | 8 +
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/krait-cc.c | 352 +++++++++++++++++++++
4 files changed, 383 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/qcom,krait-cc.txt
create mode 100644 drivers/clk/qcom/krait-cc.c

diff --git a/Documentation/devicetree/bindings/clock/qcom,krait-cc.txt b/Documentation/devicetree/bindings/clock/qcom,krait-cc.txt
new file mode 100644
index 000000000000..874138f88ec6
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/qcom,krait-cc.txt
@@ -0,0 +1,22 @@
+Krait Clock Controller
+
+PROPERTIES
+
+- compatible:
+ Usage: required
+ Value type: <string>
+ Definition: must be one of:
+ "qcom,krait-cc-v1"
+ "qcom,krait-cc-v2"
+
+- #clock-cells:
+ Usage: required
+ Value type: <u32>
+ Definition: must be 1
+
+Example:
+
+ kraitcc: clock-controller {
+ compatible = "qcom,krait-cc-v1";
+ #clock-cells = <1>;
+ };
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 92eb883533d5..6de898c366ff 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -105,6 +105,14 @@ config KPSS_XCC
if you want to support CPU frequency scaling on devices such
as MSM8960, APQ8064, etc.

+config KRAITCC
+ tristate "Krait Clock Controller"
+ depends on COMMON_CLK_QCOM && ARM
+ select KRAIT_CLOCKS
+ help
+ Support for the Krait CPU clocks on Qualcomm devices.
+ Say Y if you want to support CPU frequency scaling.
+
config KRAIT_CLOCKS
bool
select KRAIT_L2_ACCESSORS
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 6327dd623773..2477ce687208 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -24,3 +24,4 @@ obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
obj-$(CONFIG_KPSS_XCC) += kpss-xcc.o
obj-$(CONFIG_QCOM_HFPLL) += hfpll.o
+obj-$(CONFIG_KRAITCC) += krait-cc.o
diff --git a/drivers/clk/qcom/krait-cc.c b/drivers/clk/qcom/krait-cc.c
new file mode 100644
index 000000000000..f55b5ecd0df8
--- /dev/null
+++ b/drivers/clk/qcom/krait-cc.c
@@ -0,0 +1,352 @@
+/* Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+
+#include "clk-krait.h"
+
+static unsigned int sec_mux_map[] = {
+ 2,
+ 0,
+};
+
+static unsigned int pri_mux_map[] = {
+ 1,
+ 2,
+ 0,
+};
+
+static int
+krait_add_div(struct device *dev, int id, const char *s, unsigned offset)
+{
+ struct krait_div2_clk *div;
+ struct clk_init_data init = {
+ .num_parents = 1,
+ .ops = &krait_div2_clk_ops,
+ .flags = CLK_SET_RATE_PARENT,
+ };
+ const char *p_names[1];
+ struct clk *clk;
+
+ div = devm_kzalloc(dev, sizeof(*div), GFP_KERNEL);
+ if (!div)
+ return -ENOMEM;
+
+ div->width = 2;
+ div->shift = 6;
+ div->lpl = id >= 0;
+ div->offset = offset;
+ div->hw.init = &init;
+
+ init.name = kasprintf(GFP_KERNEL, "hfpll%s_div", s);
+ if (!init.name)
+ return -ENOMEM;
+
+ init.parent_names = p_names;
+ p_names[0] = kasprintf(GFP_KERNEL, "hfpll%s", s);
+ if (!p_names[0]) {
+ kfree(init.name);
+ return -ENOMEM;
+ }
+
+ clk = devm_clk_register(dev, &div->hw);
+ kfree(p_names[0]);
+ kfree(init.name);
+
+ return PTR_ERR_OR_ZERO(clk);
+}
+
+static int
+krait_add_sec_mux(struct device *dev, int id, const char *s, unsigned offset,
+ bool unique_aux)
+{
+ struct krait_mux_clk *mux;
+ static const char *sec_mux_list[] = {
+ "acpu_aux",
+ "qsb",
+ };
+ struct clk_init_data init = {
+ .parent_names = sec_mux_list,
+ .num_parents = ARRAY_SIZE(sec_mux_list),
+ .ops = &krait_mux_clk_ops,
+ .flags = CLK_SET_RATE_PARENT,
+ };
+ struct clk *clk;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ mux->offset = offset;
+ mux->lpl = id >= 0;
+ mux->has_safe_parent = true;
+ mux->safe_sel = 2;
+ mux->mask = 0x3;
+ mux->shift = 2;
+ mux->parent_map = sec_mux_map;
+ mux->hw.init = &init;
+
+ init.name = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s);
+ if (!init.name)
+ return -ENOMEM;
+
+ if (unique_aux) {
+ sec_mux_list[0] = kasprintf(GFP_KERNEL, "acpu%s_aux", s);
+ if (!sec_mux_list[0]) {
+ clk = ERR_PTR(-ENOMEM);
+ goto err_aux;
+ }
+ }
+
+ clk = devm_clk_register(dev, &mux->hw);
+
+ if (unique_aux)
+ kfree(sec_mux_list[0]);
+err_aux:
+ kfree(init.name);
+ return PTR_ERR_OR_ZERO(clk);
+}
+
+static struct clk *
+krait_add_pri_mux(struct device *dev, int id, const char *s, unsigned offset)
+{
+ struct krait_mux_clk *mux;
+ const char *p_names[3];
+ struct clk_init_data init = {
+ .parent_names = p_names,
+ .num_parents = ARRAY_SIZE(p_names),
+ .ops = &krait_mux_clk_ops,
+ .flags = CLK_SET_RATE_PARENT,
+ };
+ struct clk *clk;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return ERR_PTR(-ENOMEM);
+
+ mux->has_safe_parent = true;
+ mux->safe_sel = 0;
+ mux->mask = 0x3;
+ mux->shift = 0;
+ mux->offset = offset;
+ mux->lpl = id >= 0;
+ mux->parent_map = pri_mux_map;
+ mux->hw.init = &init;
+
+ init.name = kasprintf(GFP_KERNEL, "krait%s_pri_mux", s);
+ if (!init.name)
+ return ERR_PTR(-ENOMEM);
+
+ p_names[0] = kasprintf(GFP_KERNEL, "hfpll%s", s);
+ if (!p_names[0]) {
+ clk = ERR_PTR(-ENOMEM);
+ goto err_p0;
+ }
+
+ p_names[1] = kasprintf(GFP_KERNEL, "hfpll%s_div", s);
+ if (!p_names[1]) {
+ clk = ERR_PTR(-ENOMEM);
+ goto err_p1;
+ }
+
+ p_names[2] = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s);
+ if (!p_names[2]) {
+ clk = ERR_PTR(-ENOMEM);
+ goto err_p2;
+ }
+
+ clk = devm_clk_register(dev, &mux->hw);
+
+ kfree(p_names[2]);
+err_p2:
+ kfree(p_names[1]);
+err_p1:
+ kfree(p_names[0]);
+err_p0:
+ kfree(init.name);
+ return clk;
+}
+
+/* id < 0 for L2, otherwise id == physical CPU number */
+static struct clk *krait_add_clks(struct device *dev, int id, bool unique_aux)
+{
+ int ret;
+ unsigned offset;
+ void *p = NULL;
+ const char *s;
+ struct clk *clk;
+
+ if (id >= 0) {
+ offset = 0x4501 + (0x1000 * id);
+ s = p = kasprintf(GFP_KERNEL, "%d", id);
+ if (!s)
+ return ERR_PTR(-ENOMEM);
+ } else {
+ offset = 0x500;
+ s = "_l2";
+ }
+
+ ret = krait_add_div(dev, id, s, offset);
+ if (ret) {
+ clk = ERR_PTR(ret);
+ goto err;
+ }
+
+ ret = krait_add_sec_mux(dev, id, s, offset, unique_aux);
+ if (ret) {
+ clk = ERR_PTR(ret);
+ goto err;
+ }
+
+ clk = krait_add_pri_mux(dev, id, s, offset);
+err:
+ kfree(p);
+ return clk;
+}
+
+static struct clk *krait_of_get(struct of_phandle_args *clkspec, void *data)
+{
+ unsigned int idx = clkspec->args[0];
+ struct clk **clks = data;
+
+ if (idx >= 5) {
+ pr_err("%s: invalid clock index %d\n", __func__, idx);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return clks[idx] ? : ERR_PTR(-ENODEV);
+}
+
+static const struct of_device_id krait_cc_match_table[] = {
+ { .compatible = "qcom,krait-cc-v1", (void *)1UL },
+ { .compatible = "qcom,krait-cc-v2" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, krait_cc_match_table);
+
+static int krait_cc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct of_device_id *id;
+ unsigned long cur_rate, aux_rate;
+ int cpu;
+ struct clk *clk;
+ struct clk **clks;
+ struct clk *l2_pri_mux_clk;
+
+ id = of_match_device(krait_cc_match_table, dev);
+ if (!id)
+ return -ENODEV;
+
+ /* Rate is 1 because 0 causes problems for __clk_mux_determine_rate */
+ clk = clk_register_fixed_rate(dev, "qsb", NULL, CLK_IS_ROOT, 1);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ if (!id->data) {
+ clk = clk_register_fixed_factor(dev, "acpu_aux",
+ "gpll0_vote", 0, 1, 2);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+ }
+
+ /* Krait configurations have at most 4 CPUs and one L2 */
+ clks = devm_kcalloc(dev, 5, sizeof(*clks), GFP_KERNEL);
+ if (!clks)
+ return -ENOMEM;
+
+ for_each_possible_cpu(cpu) {
+ clk = krait_add_clks(dev, cpu, id->data);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+ clks[cpu] = clk;
+ }
+
+ l2_pri_mux_clk = krait_add_clks(dev, -1, id->data);
+ if (IS_ERR(l2_pri_mux_clk))
+ return PTR_ERR(l2_pri_mux_clk);
+ clks[4] = l2_pri_mux_clk;
+
+ /*
+ * We don't want the CPU or L2 clocks to be turned off at late init
+ * if CPUFREQ or HOTPLUG configs are disabled. So, bump up the
+ * refcount of these clocks. Any cpufreq/hotplug manager can assume
+ * that the clocks have already been prepared and enabled by the time
+ * they take over.
+ */
+ for_each_online_cpu(cpu) {
+ clk_prepare_enable(l2_pri_mux_clk);
+ WARN(clk_prepare_enable(clks[cpu]),
+ "Unable to turn on CPU%d clock", cpu);
+ }
+
+ /*
+ * Force reinit of HFPLLs and muxes to overwrite any potential
+ * incorrect configuration of HFPLLs and muxes by the bootloader.
+ * While at it, also make sure the cores are running at known rates
+ * and print the current rate.
+ *
+ * The clocks are set to aux clock rate first to make sure the
+ * secondary mux is not sourcing off of QSB. The rate is then set to
+ * two different rates to force a HFPLL reinit under all
+ * circumstances.
+ */
+ cur_rate = clk_get_rate(l2_pri_mux_clk);
+ aux_rate = 384000000;
+ if (cur_rate == 1) {
+ pr_info("L2 @ QSB rate. Forcing new rate.\n");
+ cur_rate = aux_rate;
+ }
+ clk_set_rate(l2_pri_mux_clk, aux_rate);
+ clk_set_rate(l2_pri_mux_clk, 2);
+ clk_set_rate(l2_pri_mux_clk, cur_rate);
+ pr_info("L2 @ %lu KHz\n", clk_get_rate(l2_pri_mux_clk) / 1000);
+ for_each_possible_cpu(cpu) {
+ clk = clks[cpu];
+ cur_rate = clk_get_rate(clk);
+ if (cur_rate == 1) {
+ pr_info("CPU%d @ QSB rate. Forcing new rate.\n", cpu);
+ cur_rate = aux_rate;
+ }
+ clk_set_rate(clk, aux_rate);
+ clk_set_rate(clk, 2);
+ clk_set_rate(clk, cur_rate);
+ pr_info("CPU%d @ %lu KHz\n", cpu, clk_get_rate(clk) / 1000);
+ }
+
+ of_clk_add_provider(dev->of_node, krait_of_get, clks);
+
+ return 0;
+}
+
+static struct platform_driver krait_cc_driver = {
+ .probe = krait_cc_probe,
+ .driver = {
+ .name = "krait-cc",
+ .of_match_table = krait_cc_match_table,
+ },
+};
+module_platform_driver(krait_cc_driver);
+
+MODULE_DESCRIPTION("Krait CPU Clock Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:krait-cc");