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-rw-r--r--drivers/clk/keystone/sci-clk.c542
1 files changed, 542 insertions, 0 deletions
diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
new file mode 100644
index 000000000..4cb70bed8
--- /dev/null
+++ b/drivers/clk/keystone/sci-clk.c
@@ -0,0 +1,542 @@
+/*
+ * SCI Clock driver for keystone based devices
+ *
+ * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
+ * Tero Kristo <t-kristo@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+#include <linux/bsearch.h>
+
+#define SCI_CLK_SSC_ENABLE BIT(0)
+#define SCI_CLK_ALLOW_FREQ_CHANGE BIT(1)
+#define SCI_CLK_INPUT_TERMINATION BIT(2)
+
+/**
+ * struct sci_clk_provider - TI SCI clock provider representation
+ * @sci: Handle to the System Control Interface protocol handler
+ * @ops: Pointer to the SCI ops to be used by the clocks
+ * @dev: Device pointer for the clock provider
+ * @clocks: Clocks array for this device
+ * @num_clocks: Total number of clocks for this provider
+ */
+struct sci_clk_provider {
+ const struct ti_sci_handle *sci;
+ const struct ti_sci_clk_ops *ops;
+ struct device *dev;
+ struct sci_clk **clocks;
+ int num_clocks;
+};
+
+/**
+ * struct sci_clk - TI SCI clock representation
+ * @hw: Hardware clock cookie for common clock framework
+ * @dev_id: Device index
+ * @clk_id: Clock index
+ * @num_parents: Number of parents for this clock
+ * @provider: Master clock provider
+ * @flags: Flags for the clock
+ */
+struct sci_clk {
+ struct clk_hw hw;
+ u16 dev_id;
+ u8 clk_id;
+ u8 num_parents;
+ struct sci_clk_provider *provider;
+ u8 flags;
+};
+
+#define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw)
+
+/**
+ * sci_clk_prepare - Prepare (enable) a TI SCI clock
+ * @hw: clock to prepare
+ *
+ * Prepares a clock to be actively used. Returns the SCI protocol status.
+ */
+static int sci_clk_prepare(struct clk_hw *hw)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+ bool enable_ssc = clk->flags & SCI_CLK_SSC_ENABLE;
+ bool allow_freq_change = clk->flags & SCI_CLK_ALLOW_FREQ_CHANGE;
+ bool input_termination = clk->flags & SCI_CLK_INPUT_TERMINATION;
+
+ return clk->provider->ops->get_clock(clk->provider->sci, clk->dev_id,
+ clk->clk_id, enable_ssc,
+ allow_freq_change,
+ input_termination);
+}
+
+/**
+ * sci_clk_unprepare - Un-prepares (disables) a TI SCI clock
+ * @hw: clock to unprepare
+ *
+ * Un-prepares a clock from active state.
+ */
+static void sci_clk_unprepare(struct clk_hw *hw)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+ int ret;
+
+ ret = clk->provider->ops->put_clock(clk->provider->sci, clk->dev_id,
+ clk->clk_id);
+ if (ret)
+ dev_err(clk->provider->dev,
+ "unprepare failed for dev=%d, clk=%d, ret=%d\n",
+ clk->dev_id, clk->clk_id, ret);
+}
+
+/**
+ * sci_clk_is_prepared - Check if a TI SCI clock is prepared or not
+ * @hw: clock to check status for
+ *
+ * Checks if a clock is prepared (enabled) in hardware. Returns non-zero
+ * value if clock is enabled, zero otherwise.
+ */
+static int sci_clk_is_prepared(struct clk_hw *hw)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+ bool req_state, current_state;
+ int ret;
+
+ ret = clk->provider->ops->is_on(clk->provider->sci, clk->dev_id,
+ clk->clk_id, &req_state,
+ &current_state);
+ if (ret) {
+ dev_err(clk->provider->dev,
+ "is_prepared failed for dev=%d, clk=%d, ret=%d\n",
+ clk->dev_id, clk->clk_id, ret);
+ return 0;
+ }
+
+ return req_state;
+}
+
+/**
+ * sci_clk_recalc_rate - Get clock rate for a TI SCI clock
+ * @hw: clock to get rate for
+ * @parent_rate: parent rate provided by common clock framework, not used
+ *
+ * Gets the current clock rate of a TI SCI clock. Returns the current
+ * clock rate, or zero in failure.
+ */
+static unsigned long sci_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+ u64 freq;
+ int ret;
+
+ ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id,
+ clk->clk_id, &freq);
+ if (ret) {
+ dev_err(clk->provider->dev,
+ "recalc-rate failed for dev=%d, clk=%d, ret=%d\n",
+ clk->dev_id, clk->clk_id, ret);
+ return 0;
+ }
+
+ return freq;
+}
+
+/**
+ * sci_clk_determine_rate - Determines a clock rate a clock can be set to
+ * @hw: clock to change rate for
+ * @req: requested rate configuration for the clock
+ *
+ * Determines a suitable clock rate and parent for a TI SCI clock.
+ * The parent handling is un-used, as generally the parent clock rates
+ * are not known by the kernel; instead these are internally handled
+ * by the firmware. Returns 0 on success, negative error value on failure.
+ */
+static int sci_clk_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+ int ret;
+ u64 new_rate;
+
+ ret = clk->provider->ops->get_best_match_freq(clk->provider->sci,
+ clk->dev_id,
+ clk->clk_id,
+ req->min_rate,
+ req->rate,
+ req->max_rate,
+ &new_rate);
+ if (ret) {
+ dev_err(clk->provider->dev,
+ "determine-rate failed for dev=%d, clk=%d, ret=%d\n",
+ clk->dev_id, clk->clk_id, ret);
+ return ret;
+ }
+
+ req->rate = new_rate;
+
+ return 0;
+}
+
+/**
+ * sci_clk_set_rate - Set rate for a TI SCI clock
+ * @hw: clock to change rate for
+ * @rate: target rate for the clock
+ * @parent_rate: rate of the clock parent, not used for TI SCI clocks
+ *
+ * Sets a clock frequency for a TI SCI clock. Returns the TI SCI
+ * protocol status.
+ */
+static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+
+ return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
+ clk->clk_id, rate, rate, rate);
+}
+
+/**
+ * sci_clk_get_parent - Get the current parent of a TI SCI clock
+ * @hw: clock to get parent for
+ *
+ * Returns the index of the currently selected parent for a TI SCI clock.
+ */
+static u8 sci_clk_get_parent(struct clk_hw *hw)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+ u8 parent_id;
+ int ret;
+
+ ret = clk->provider->ops->get_parent(clk->provider->sci, clk->dev_id,
+ clk->clk_id, &parent_id);
+ if (ret) {
+ dev_err(clk->provider->dev,
+ "get-parent failed for dev=%d, clk=%d, ret=%d\n",
+ clk->dev_id, clk->clk_id, ret);
+ return 0;
+ }
+
+ return parent_id - clk->clk_id - 1;
+}
+
+/**
+ * sci_clk_set_parent - Set the parent of a TI SCI clock
+ * @hw: clock to set parent for
+ * @index: new parent index for the clock
+ *
+ * Sets the parent of a TI SCI clock. Return TI SCI protocol status.
+ */
+static int sci_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct sci_clk *clk = to_sci_clk(hw);
+
+ return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
+ clk->clk_id,
+ index + 1 + clk->clk_id);
+}
+
+static const struct clk_ops sci_clk_ops = {
+ .prepare = sci_clk_prepare,
+ .unprepare = sci_clk_unprepare,
+ .is_prepared = sci_clk_is_prepared,
+ .recalc_rate = sci_clk_recalc_rate,
+ .determine_rate = sci_clk_determine_rate,
+ .set_rate = sci_clk_set_rate,
+ .get_parent = sci_clk_get_parent,
+ .set_parent = sci_clk_set_parent,
+};
+
+/**
+ * _sci_clk_get - Gets a handle for an SCI clock
+ * @provider: Handle to SCI clock provider
+ * @sci_clk: Handle to the SCI clock to populate
+ *
+ * Gets a handle to an existing TI SCI hw clock, or builds a new clock
+ * entry and registers it with the common clock framework. Called from
+ * the common clock framework, when a corresponding of_clk_get call is
+ * executed, or recursively from itself when parsing parent clocks.
+ * Returns 0 on success, negative error code on failure.
+ */
+static int _sci_clk_build(struct sci_clk_provider *provider,
+ struct sci_clk *sci_clk)
+{
+ struct clk_init_data init = { NULL };
+ char *name = NULL;
+ char **parent_names = NULL;
+ int i;
+ int ret = 0;
+
+ name = kasprintf(GFP_KERNEL, "%s:%d:%d", dev_name(provider->dev),
+ sci_clk->dev_id, sci_clk->clk_id);
+
+ init.name = name;
+
+ /*
+ * From kernel point of view, we only care about a clocks parents,
+ * if it has more than 1 possible parent. In this case, it is going
+ * to have mux functionality. Otherwise it is going to act as a root
+ * clock.
+ */
+ if (sci_clk->num_parents < 2)
+ sci_clk->num_parents = 0;
+
+ if (sci_clk->num_parents) {
+ parent_names = kcalloc(sci_clk->num_parents, sizeof(char *),
+ GFP_KERNEL);
+
+ if (!parent_names) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ for (i = 0; i < sci_clk->num_parents; i++) {
+ char *parent_name;
+
+ parent_name = kasprintf(GFP_KERNEL, "%s:%d:%d",
+ dev_name(provider->dev),
+ sci_clk->dev_id,
+ sci_clk->clk_id + 1 + i);
+ if (!parent_name) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ parent_names[i] = parent_name;
+ }
+ init.parent_names = (void *)parent_names;
+ }
+
+ init.ops = &sci_clk_ops;
+ init.num_parents = sci_clk->num_parents;
+ sci_clk->hw.init = &init;
+
+ ret = devm_clk_hw_register(provider->dev, &sci_clk->hw);
+ if (ret)
+ dev_err(provider->dev, "failed clk register with %d\n", ret);
+
+err:
+ if (parent_names) {
+ for (i = 0; i < sci_clk->num_parents; i++)
+ kfree(parent_names[i]);
+
+ kfree(parent_names);
+ }
+
+ kfree(name);
+
+ return ret;
+}
+
+static int _cmp_sci_clk(const void *a, const void *b)
+{
+ const struct sci_clk *ca = a;
+ const struct sci_clk *cb = *(struct sci_clk **)b;
+
+ if (ca->dev_id == cb->dev_id && ca->clk_id == cb->clk_id)
+ return 0;
+ if (ca->dev_id > cb->dev_id ||
+ (ca->dev_id == cb->dev_id && ca->clk_id > cb->clk_id))
+ return 1;
+ return -1;
+}
+
+/**
+ * sci_clk_get - Xlate function for getting clock handles
+ * @clkspec: device tree clock specifier
+ * @data: pointer to the clock provider
+ *
+ * Xlate function for retrieving clock TI SCI hw clock handles based on
+ * device tree clock specifier. Called from the common clock framework,
+ * when a corresponding of_clk_get call is executed. Returns a pointer
+ * to the TI SCI hw clock struct, or ERR_PTR value in failure.
+ */
+static struct clk_hw *sci_clk_get(struct of_phandle_args *clkspec, void *data)
+{
+ struct sci_clk_provider *provider = data;
+ struct sci_clk **clk;
+ struct sci_clk key;
+
+ if (clkspec->args_count != 2)
+ return ERR_PTR(-EINVAL);
+
+ key.dev_id = clkspec->args[0];
+ key.clk_id = clkspec->args[1];
+
+ clk = bsearch(&key, provider->clocks, provider->num_clocks,
+ sizeof(clk), _cmp_sci_clk);
+
+ if (!clk)
+ return ERR_PTR(-ENODEV);
+
+ return &(*clk)->hw;
+}
+
+static int ti_sci_init_clocks(struct sci_clk_provider *p)
+{
+ int i;
+ int ret;
+
+ for (i = 0; i < p->num_clocks; i++) {
+ ret = _sci_clk_build(p, p->clocks[i]);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id ti_sci_clk_of_match[] = {
+ { .compatible = "ti,k2g-sci-clk" },
+ { /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ti_sci_clk_of_match);
+
+/**
+ * ti_sci_clk_probe - Probe function for the TI SCI clock driver
+ * @pdev: platform device pointer to be probed
+ *
+ * Probes the TI SCI clock device. Allocates a new clock provider
+ * and registers this to the common clock framework. Also applies
+ * any required flags to the identified clocks via clock lists
+ * supplied from DT. Returns 0 for success, negative error value
+ * for failure.
+ */
+static int ti_sci_clk_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct sci_clk_provider *provider;
+ const struct ti_sci_handle *handle;
+ int ret;
+ int num_clks = 0;
+ struct sci_clk **clks = NULL;
+ struct sci_clk **tmp_clks;
+ struct sci_clk *sci_clk;
+ int max_clks = 0;
+ int clk_id = 0;
+ int dev_id = 0;
+ u8 num_parents;
+ int gap_size = 0;
+
+ handle = devm_ti_sci_get_handle(dev);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
+ if (!provider)
+ return -ENOMEM;
+
+ provider->sci = handle;
+ provider->ops = &handle->ops.clk_ops;
+ provider->dev = dev;
+
+ while (1) {
+ ret = provider->ops->get_num_parents(provider->sci, dev_id,
+ clk_id, &num_parents);
+ if (ret) {
+ gap_size++;
+ if (!clk_id) {
+ if (gap_size >= 5)
+ break;
+ dev_id++;
+ } else {
+ if (gap_size >= 2) {
+ dev_id++;
+ clk_id = 0;
+ gap_size = 0;
+ } else {
+ clk_id++;
+ }
+ }
+ continue;
+ }
+
+ gap_size = 0;
+
+ if (num_clks == max_clks) {
+ tmp_clks = devm_kmalloc_array(dev, max_clks + 64,
+ sizeof(sci_clk),
+ GFP_KERNEL);
+ memcpy(tmp_clks, clks, max_clks * sizeof(sci_clk));
+ if (max_clks)
+ devm_kfree(dev, clks);
+ max_clks += 64;
+ clks = tmp_clks;
+ }
+
+ sci_clk = devm_kzalloc(dev, sizeof(*sci_clk), GFP_KERNEL);
+ if (!sci_clk)
+ return -ENOMEM;
+ sci_clk->dev_id = dev_id;
+ sci_clk->clk_id = clk_id;
+ sci_clk->provider = provider;
+ sci_clk->num_parents = num_parents;
+
+ clks[num_clks] = sci_clk;
+
+ clk_id++;
+ num_clks++;
+ }
+
+ provider->clocks = devm_kmalloc_array(dev, num_clks, sizeof(sci_clk),
+ GFP_KERNEL);
+ if (!provider->clocks)
+ return -ENOMEM;
+
+ memcpy(provider->clocks, clks, num_clks * sizeof(sci_clk));
+
+ provider->num_clocks = num_clks;
+
+ devm_kfree(dev, clks);
+
+ ret = ti_sci_init_clocks(provider);
+ if (ret) {
+ pr_err("ti-sci-init-clocks failed.\n");
+ return ret;
+ }
+
+ return of_clk_add_hw_provider(np, sci_clk_get, provider);
+}
+
+/**
+ * ti_sci_clk_remove - Remove TI SCI clock device
+ * @pdev: platform device pointer for the device to be removed
+ *
+ * Removes the TI SCI device. Unregisters the clock provider registered
+ * via common clock framework. Any memory allocated for the device will
+ * be free'd silently via the devm framework. Returns 0 always.
+ */
+static int ti_sci_clk_remove(struct platform_device *pdev)
+{
+ of_clk_del_provider(pdev->dev.of_node);
+
+ return 0;
+}
+
+static struct platform_driver ti_sci_clk_driver = {
+ .probe = ti_sci_clk_probe,
+ .remove = ti_sci_clk_remove,
+ .driver = {
+ .name = "ti-sci-clk",
+ .of_match_table = of_match_ptr(ti_sci_clk_of_match),
+ },
+};
+module_platform_driver(ti_sci_clk_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TI System Control Interface(SCI) Clock driver");
+MODULE_AUTHOR("Tero Kristo");
+MODULE_ALIAS("platform:ti-sci-clk");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 08:23:21 +0000