/* * SCI Clock driver for keystone based devices * * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/ * Tero Kristo * * 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 #include #include #include #include #include #include #include #include #include #include #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++; break; } 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");