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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * SCI Clock driver for keystone based devices
- *
- * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
- * Tero Kristo <[email protected]>
- */
- #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>
- #include <linux/list_sort.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
- * @node: Link for handling clocks probed via DT
- * @cached_req: Cached requested freq for determine rate calls
- * @cached_res: Cached result freq for determine rate calls
- */
- struct sci_clk {
- struct clk_hw hw;
- u16 dev_id;
- u32 clk_id;
- u32 num_parents;
- struct sci_clk_provider *provider;
- u8 flags;
- struct list_head node;
- unsigned long cached_req;
- unsigned long cached_res;
- };
- #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,
- ¤t_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;
- if (clk->cached_req && clk->cached_req == req->rate) {
- req->rate = clk->cached_res;
- return 0;
- }
- 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;
- }
- clk->cached_req = req->rate;
- clk->cached_res = new_rate;
- 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 / 10 * 9, rate,
- rate / 10 * 11);
- }
- /**
- * 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);
- u32 parent_id = 0;
- int ret;
- ret = clk->provider->ops->get_parent(clk->provider->sci, clk->dev_id,
- clk->clk_id, (void *)&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;
- }
- parent_id = parent_id - clk->clk_id - 1;
- return (u8)parent_id;
- }
- /**
- * 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);
- clk->cached_req = 0;
- 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, "clk:%d:%d", sci_clk->dev_id,
- sci_clk->clk_id);
- if (!name)
- return -ENOMEM;
- 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, "clk:%d:%d",
- 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);
- #ifdef CONFIG_TI_SCI_CLK_PROBE_FROM_FW
- static int ti_sci_scan_clocks_from_fw(struct sci_clk_provider *provider)
- {
- 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;
- u32 num_parents = 0;
- int gap_size = 0;
- struct device *dev = provider->dev;
- while (1) {
- ret = provider->ops->get_num_parents(provider->sci, dev_id,
- clk_id,
- (void *)&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);
- return 0;
- }
- #else
- static int _cmp_sci_clk_list(void *priv, const struct list_head *a,
- const struct list_head *b)
- {
- struct sci_clk *ca = container_of(a, struct sci_clk, node);
- struct sci_clk *cb = container_of(b, struct sci_clk, node);
- return _cmp_sci_clk(ca, &cb);
- }
- static int ti_sci_scan_clocks_from_dt(struct sci_clk_provider *provider)
- {
- struct device *dev = provider->dev;
- struct device_node *np = NULL;
- int ret;
- int index;
- struct of_phandle_args args;
- struct list_head clks;
- struct sci_clk *sci_clk, *prev;
- int num_clks = 0;
- int num_parents;
- int clk_id;
- const char * const clk_names[] = {
- "clocks", "assigned-clocks", "assigned-clock-parents", NULL
- };
- const char * const *clk_name;
- INIT_LIST_HEAD(&clks);
- clk_name = clk_names;
- while (*clk_name) {
- np = of_find_node_with_property(np, *clk_name);
- if (!np) {
- clk_name++;
- continue;
- }
- if (!of_device_is_available(np))
- continue;
- index = 0;
- do {
- ret = of_parse_phandle_with_args(np, *clk_name,
- "#clock-cells", index,
- &args);
- if (ret)
- break;
- if (args.args_count == 2 && args.np == dev->of_node) {
- sci_clk = devm_kzalloc(dev, sizeof(*sci_clk),
- GFP_KERNEL);
- if (!sci_clk)
- return -ENOMEM;
- sci_clk->dev_id = args.args[0];
- sci_clk->clk_id = args.args[1];
- sci_clk->provider = provider;
- provider->ops->get_num_parents(provider->sci,
- sci_clk->dev_id,
- sci_clk->clk_id,
- (void *)&sci_clk->num_parents);
- list_add_tail(&sci_clk->node, &clks);
- num_clks++;
- num_parents = sci_clk->num_parents;
- if (num_parents == 1)
- num_parents = 0;
- /*
- * Linux kernel has inherent limitation
- * of 255 clock parents at the moment.
- * Right now, it is not expected that
- * any mux clock from sci-clk driver
- * would exceed that limit either, but
- * the ABI basically provides that
- * possibility. Print out a warning if
- * this happens for any clock.
- */
- if (num_parents >= 255) {
- dev_warn(dev, "too many parents for dev=%d, clk=%d (%d), cropping to 255.\n",
- sci_clk->dev_id,
- sci_clk->clk_id, num_parents);
- num_parents = 255;
- }
- clk_id = args.args[1] + 1;
- while (num_parents--) {
- sci_clk = devm_kzalloc(dev,
- sizeof(*sci_clk),
- GFP_KERNEL);
- if (!sci_clk)
- return -ENOMEM;
- sci_clk->dev_id = args.args[0];
- sci_clk->clk_id = clk_id++;
- sci_clk->provider = provider;
- list_add_tail(&sci_clk->node, &clks);
- num_clks++;
- }
- }
- index++;
- } while (args.np);
- }
- list_sort(NULL, &clks, _cmp_sci_clk_list);
- provider->clocks = devm_kmalloc_array(dev, num_clks, sizeof(sci_clk),
- GFP_KERNEL);
- if (!provider->clocks)
- return -ENOMEM;
- num_clks = 0;
- prev = NULL;
- list_for_each_entry(sci_clk, &clks, node) {
- if (prev && prev->dev_id == sci_clk->dev_id &&
- prev->clk_id == sci_clk->clk_id)
- continue;
- provider->clocks[num_clks++] = sci_clk;
- prev = sci_clk;
- }
- provider->num_clocks = num_clks;
- return 0;
- }
- #endif
- /**
- * 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;
- 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;
- #ifdef CONFIG_TI_SCI_CLK_PROBE_FROM_FW
- ret = ti_sci_scan_clocks_from_fw(provider);
- if (ret) {
- dev_err(dev, "scan clocks from FW failed: %d\n", ret);
- return ret;
- }
- #else
- ret = ti_sci_scan_clocks_from_dt(provider);
- if (ret) {
- dev_err(dev, "scan clocks from DT failed: %d\n", ret);
- return ret;
- }
- #endif
- 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");
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