| /* |
| * 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> |
| #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 |
| */ |
| 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; |
| }; |
| |
| #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; |
| |
| 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); |
| 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); |
| |
| 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); |
| |
| 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, struct list_head *a, |
| 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"); |