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Subject[PATCH V3] clk: qcom: Add spmi_pmic clock divider support
Date
Clkdiv module provides a clock output on the PMIC with CXO as
the source. This clock can be routed through PMIC GPIOs. Add
a device driver to configure this clkdiv module.

Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
---
.../bindings/clock/clk-spmi-pmic-div.txt | 51 +++
drivers/clk/qcom/Kconfig | 9 +
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/clk-spmi-pmic-div.c | 342 +++++++++++++++++++++
4 files changed, 403 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/clk-spmi-pmic-div.txt
create mode 100644 drivers/clk/qcom/clk-spmi-pmic-div.c

diff --git a/Documentation/devicetree/bindings/clock/clk-spmi-pmic-div.txt b/Documentation/devicetree/bindings/clock/clk-spmi-pmic-div.txt
new file mode 100644
index 0000000..8b84b32
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/clk-spmi-pmic-div.txt
@@ -0,0 +1,51 @@
+Qualcomm Technologies, Inc. SPMI PMIC clock divider (clkdiv)
+
+clkdiv configures the clock frequency of a set of outputs on the PMIC.
+These clocks are typically wired through alternate functions on
+gpio pins.
+
+=======================
+Properties
+=======================
+
+- compatible
+ Usage: required
+ Value type: <string>
+ Definition: must be one of:
+ "qcom,spmi-clkdiv"
+ "qcom,pm8998-clkdiv"
+
+- reg
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: Addresses and sizes for the memory of this CLKDIV
+ peripheral.
+
+- clocks:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: reference to the xo clock.
+
+- clock-names:
+ Usage: required
+ Value type: <stringlist>
+ Definition: must be "xo".
+
+=======
+Example
+=======
+
+pm8998_clk_divs: qcom,clkdiv@5b00 {
+ compatible = "qcom,pm8998-clkdiv";
+ reg = <0x5b00>;
+ #clock-cells = <1>;
+ clocks = <&xo_board>;
+ clock-names = "xo";
+
+ assigned-clocks = <&pm8998_clk_divs 1>,
+ <&pm8998_clk_divs 2>,
+ <&pm8998_clk_divs 3>;
+ assigned-clock-rates = <9600000>,
+ <9600000>,
+ <9600000>;
+};
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 9f6c278..dd5b18e 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -196,3 +196,12 @@ config MSM_MMCC_8996
Support for the multimedia clock controller on msm8996 devices.
Say Y if you want to support multimedia devices such as display,
graphics, video encode/decode, camera, etc.
+
+config SPMI_PMIC_CLKDIV
+ tristate "spmi pmic clkdiv driver"
+ depends on (COMMON_CLK_QCOM && SPMI) || COMPILE_TEST
+ help
+ This driver supports the clkdiv functionality on the Qualcomm
+ Technologies, Inc. SPMI PMIC. It configures the frequency of
+ clkdiv outputs on the PMIC. These clocks are typically wired
+ through alternate functions on gpio pins.
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 3f3aff2..4d4c62b 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
+obj-$(CONFIG_SPMI_PMIC_CLKDIV) += clk-spmi-pmic-div.o
diff --git a/drivers/clk/qcom/clk-spmi-pmic-div.c b/drivers/clk/qcom/clk-spmi-pmic-div.c
new file mode 100644
index 0000000..2a71b64
--- /dev/null
+++ b/drivers/clk/qcom/clk-spmi-pmic-div.c
@@ -0,0 +1,342 @@
+/* Copyright (c) 2017, 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/bitops.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define REG_DIV_CTL1 0x43
+#define DIV_CTL1_DIV_FACTOR_MASK GENMASK(2, 0)
+
+#define REG_EN_CTL 0x46
+#define REG_EN_MASK BIT(7)
+
+#define ENABLE_DELAY_NS(cxo_ns, div) ((2 + 3 * div) * cxo_ns)
+#define DISABLE_DELAY_NS(cxo_ns, div) ((3 * div) * cxo_ns)
+
+#define CLK_SPMI_PMIC_DIV_OFFSET 1
+
+#define CLKDIV_XO_DIV_1_0 0
+#define CLKDIV_XO_DIV_1 1
+#define CLKDIV_XO_DIV_2 2
+#define CLKDIV_XO_DIV_4 3
+#define CLKDIV_XO_DIV_8 4
+#define CLKDIV_XO_DIV_16 5
+#define CLKDIV_XO_DIV_32 6
+#define CLKDIV_XO_DIV_64 7
+#define CLKDIV_MAX_ALLOWED 8
+
+struct clkdiv {
+ struct regmap *regmap;
+ u16 base;
+ spinlock_t lock;
+
+ /* clock properties */
+ struct clk_hw hw;
+ unsigned int div_factor;
+ unsigned int cxo_period_ns;
+};
+
+static inline struct clkdiv *to_clkdiv(struct clk_hw *hw)
+{
+ return container_of(hw, struct clkdiv, hw);
+}
+
+static inline unsigned int div_factor_to_div(unsigned int div_factor)
+{
+ if (div_factor == CLKDIV_XO_DIV_1_0)
+ return 1;
+
+ return 1 << (div_factor - CLK_SPMI_PMIC_DIV_OFFSET);
+}
+
+static inline unsigned int div_to_div_factor(unsigned int div)
+{
+ return min(ilog2(div) + CLK_SPMI_PMIC_DIV_OFFSET,
+ CLKDIV_MAX_ALLOWED - 1);
+}
+
+static bool is_spmi_pmic_clkdiv_enabled(struct clkdiv *clkdiv)
+{
+ unsigned int val = 0;
+
+ regmap_read(clkdiv->regmap, clkdiv->base + REG_EN_CTL,
+ &val);
+ return (val & REG_EN_MASK) ? true : false;
+}
+
+static int spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv,
+ bool enable_state)
+{
+ int rc;
+
+ rc = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_EN_CTL,
+ REG_EN_MASK,
+ (enable_state == true) ? REG_EN_MASK : 0);
+ if (rc)
+ return rc;
+
+ if (enable_state == true)
+ ndelay(ENABLE_DELAY_NS(clkdiv->cxo_period_ns,
+ div_factor_to_div(clkdiv->div_factor)));
+ else
+ ndelay(DISABLE_DELAY_NS(clkdiv->cxo_period_ns,
+ div_factor_to_div(clkdiv->div_factor)));
+
+ return rc;
+}
+
+static int spmi_pmic_clkdiv_config_freq_div(struct clkdiv *clkdiv,
+ unsigned int div)
+{
+ unsigned int div_factor;
+ unsigned long flags;
+ bool enabled;
+ int rc;
+
+ div_factor = div_to_div_factor(div);
+
+ spin_lock_irqsave(&clkdiv->lock, flags);
+
+ enabled = is_spmi_pmic_clkdiv_enabled(clkdiv);
+ if (enabled) {
+ rc = spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
+ if (rc)
+ goto fail;
+ }
+
+ rc = regmap_update_bits(clkdiv->regmap,
+ clkdiv->base + REG_DIV_CTL1,
+ DIV_CTL1_DIV_FACTOR_MASK, div_factor);
+ if (rc)
+ goto fail;
+
+ clkdiv->div_factor = div_factor;
+
+ if (enabled)
+ rc = spmi_pmic_clkdiv_set_enable_state(clkdiv, true);
+
+fail:
+ spin_unlock_irqrestore(&clkdiv->lock, flags);
+ return rc;
+}
+
+static int clk_spmi_pmic_div_enable(struct clk_hw *hw)
+{
+ struct clkdiv *clkdiv = to_clkdiv(hw);
+ unsigned long flags;
+ int rc;
+
+ spin_lock_irqsave(&clkdiv->lock, flags);
+ rc = spmi_pmic_clkdiv_set_enable_state(clkdiv, true);
+ spin_unlock_irqrestore(&clkdiv->lock, flags);
+
+ return rc;
+}
+
+static void clk_spmi_pmic_div_disable(struct clk_hw *hw)
+{
+ struct clkdiv *clkdiv = to_clkdiv(hw);
+ unsigned long flags;
+
+ spin_lock_irqsave(&clkdiv->lock, flags);
+ spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
+ spin_unlock_irqrestore(&clkdiv->lock, flags);
+}
+
+static long clk_spmi_pmic_div_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ unsigned long new_rate;
+ unsigned int div, div_factor;
+
+ div = DIV_ROUND_UP(*parent_rate, rate);
+ div_factor = div_to_div_factor(div);
+ new_rate = *parent_rate / div_factor_to_div(div_factor);
+
+ return new_rate;
+}
+
+static unsigned long clk_spmi_pmic_div_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clkdiv *clkdiv = to_clkdiv(hw);
+ unsigned long rate;
+
+ rate = parent_rate / div_factor_to_div(clkdiv->div_factor);
+
+ return rate;
+}
+
+static int clk_spmi_pmic_div_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clkdiv *clkdiv = to_clkdiv(hw);
+
+ return spmi_pmic_clkdiv_config_freq_div(clkdiv, parent_rate / rate);
+}
+
+static const struct clk_ops clk_spmi_pmic_div_ops = {
+ .enable = clk_spmi_pmic_div_enable,
+ .disable = clk_spmi_pmic_div_disable,
+ .set_rate = clk_spmi_pmic_div_set_rate,
+ .recalc_rate = clk_spmi_pmic_div_recalc_rate,
+ .round_rate = clk_spmi_pmic_div_round_rate,
+};
+
+struct spmi_pmic_div_clk_cc {
+ struct clk_hw **div_clks;
+ int nclks;
+};
+
+#define SPMI_PMIC_CLKDIV_MIN_INDEX 1
+
+static struct clk_hw *spmi_pmic_div_clk_hw_get(struct of_phandle_args *clkspec,
+ void *data)
+{
+ struct spmi_pmic_div_clk_cc *clk_cc = data;
+ unsigned int idx = (clkspec->args[0] - SPMI_PMIC_CLKDIV_MIN_INDEX);
+
+ if (idx < 0 || idx >= clk_cc->nclks) {
+ pr_err("%s: index value %u is invalid; allowed range: [%d, %d]\n",
+ __func__, SPMI_PMIC_CLKDIV_MIN_INDEX, clk_cc->nclks);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return clk_cc->div_clks[idx];
+}
+
+#define SPMI_PMIC_DIV_CLK_SIZE 0x100
+
+static const struct of_device_id spmi_pmic_clkdiv_match_table[] = {
+ {
+ .compatible = "qcom,spmi-clkdiv",
+ .data = (void *)(uintptr_t)1, /* Generic */
+ },
+ {
+ .compatible = "qcom,pm8998-clkdiv",
+ .data = (void *)(uintptr_t)3, /* 3 div_clks */
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, spmi_pmic_clkdiv_match_table);
+
+static int spmi_pmic_clkdiv_probe(struct platform_device *pdev)
+{
+ struct spmi_pmic_div_clk_cc *clk_cc;
+ struct clk_init_data init = {};
+ struct clkdiv *clkdiv;
+ struct clk *cxo;
+ struct regmap *regmap;
+ struct device *dev = &pdev->dev;
+ const char *parent_name;
+ int nclks, i, rc, cxo_hz;
+ u32 start;
+
+ rc = of_property_read_u32(dev->of_node, "reg", &start);
+ if (rc < 0) {
+ dev_err(dev, "reg property reading failed\n");
+ return rc;
+ }
+
+ regmap = dev_get_regmap(dev->parent, NULL);
+ if (!regmap) {
+ dev_err(dev, "Couldn't get parent's regmap\n");
+ return -EINVAL;
+ }
+
+ nclks = (uintptr_t)of_match_node(spmi_pmic_clkdiv_match_table,
+ dev->of_node)->data;
+
+ clkdiv = devm_kcalloc(dev, nclks, sizeof(*clkdiv), GFP_KERNEL);
+ if (!clkdiv)
+ return -ENOMEM;
+
+ clk_cc = devm_kzalloc(&pdev->dev, sizeof(*clk_cc), GFP_KERNEL);
+ if (!clk_cc)
+ return -ENOMEM;
+
+ clk_cc->div_clks = devm_kcalloc(&pdev->dev, nclks,
+ sizeof(*clk_cc->div_clks), GFP_KERNEL);
+ if (!clk_cc->div_clks)
+ return -ENOMEM;
+
+ cxo = clk_get(dev, "xo");
+ if (IS_ERR(cxo)) {
+ rc = PTR_ERR(cxo);
+ if (rc != -EPROBE_DEFER)
+ dev_err(dev, "failed to get xo clock");
+ return rc;
+ }
+ cxo_hz = clk_get_rate(cxo);
+ clk_put(cxo);
+
+ parent_name = of_clk_get_parent_name(dev->of_node, 0);
+ if (!parent_name) {
+ dev_err(dev, "missing parent clock\n");
+ return -ENODEV;
+ }
+
+ init.parent_names = &parent_name;
+ init.num_parents = parent_name ? 1 : 0;
+ init.ops = &clk_spmi_pmic_div_ops;
+ init.flags = 0;
+
+ for (i = 0; i < nclks; i++) {
+ spin_lock_init(&clkdiv[i].lock);
+ clkdiv[i].base = start + i * SPMI_PMIC_DIV_CLK_SIZE;
+ clkdiv[i].regmap = regmap;
+ clkdiv[i].cxo_period_ns = NSEC_PER_SEC / cxo_hz;
+ init.name = kasprintf(GFP_KERNEL, "div_clk%d", i + 1);
+ clkdiv[i].hw.init = &init;
+ rc = devm_clk_hw_register(dev, &clkdiv[i].hw);
+ kfree(init.name); /* clock framework made a copy of the name */
+ if (rc)
+ return rc;
+
+ clk_cc->div_clks[i] = &clkdiv[i].hw;
+ }
+
+ clk_cc->nclks = nclks;
+ rc = of_clk_add_hw_provider(pdev->dev.of_node, spmi_pmic_div_clk_hw_get,
+ clk_cc);
+ return rc;
+}
+
+static int spmi_pmic_clkdiv_remove(struct platform_device *pdev)
+{
+ of_clk_del_provider(pdev->dev.of_node);
+
+ return 0;
+}
+
+static struct platform_driver spmi_pmic_clkdiv_driver = {
+ .driver = {
+ .name = "qcom,spmi-pmic-clkdiv",
+ .of_match_table = spmi_pmic_clkdiv_match_table,
+ },
+ .probe = spmi_pmic_clkdiv_probe,
+ .remove = spmi_pmic_clkdiv_remove,
+};
+module_platform_driver(spmi_pmic_clkdiv_driver);
+
+MODULE_DESCRIPTION("QCOM SPMI PMIC clkdiv driver");
+MODULE_LICENSE("GPL v2");
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
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