/* * 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 #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: List of all registered clocks * @lock: Mutex for locking access to the @clocks list */ struct sci_clk_provider { const struct ti_sci_handle *sci; const struct ti_sci_clk_ops *ops; struct device *dev; struct list_head clocks; struct mutex lock; /* Protects access to the @clocks list */ }; /** * struct sci_clk - TI SCI clock representation * @hw: Hardware clock cookie for common clock framework * @dev_id: Device index * @clk_id: Clock index * @node: Clocks list link * @provider: Master clock provider * @flags: Flags for the clock */ struct sci_clk { struct clk_hw hw; u16 dev_id; u8 clk_id; struct list_head node; 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, ¤t_state); if (ret) { dev_err(clk->provider->dev, "prepare 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 (u32)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 and sets the new rate in the req->rate field * on success, returns < 0 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); u64 new_rate; int ret; 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); u64 freq = rate; return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id, clk->clk_id, freq, freq, freq); } /** * 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; } parent_id = parent_id - clk->clk_id - 1; return 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 * @dev_id: device ID for the clock to register * @clk_id: clock ID for the clock to register * @parse_parents: indicator whether parents for this clock should be handled * * Gets a handle to an existing TI SCI 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 a pointer to the clock struct, or ERR_PTR value in failure. */ static struct clk *_sci_clk_get(struct sci_clk_provider *provider, u16 dev_id, u8 clk_id, bool parse_parents) { struct clk_init_data init = { NULL }; struct clk *clk; struct sci_clk *sci_clk = NULL; char name[20]; char **parent_names = NULL; int i; int ret; list_for_each_entry(sci_clk, &provider->clocks, node) if (sci_clk->dev_id == dev_id && sci_clk->clk_id == clk_id) return sci_clk->hw.clk; sci_clk = devm_kzalloc(provider->dev, sizeof(*sci_clk), GFP_KERNEL); if (!sci_clk) { ret = -ENOMEM; goto err; } sci_clk->dev_id = dev_id; sci_clk->clk_id = clk_id; sci_clk->provider = provider; if (parse_parents) { ret = provider->ops->get_num_parents(provider->sci, dev_id, clk_id, &init.num_parents); if (ret) goto err; } snprintf(name, 20, "%s:%d:%d", dev_name(provider->dev), sci_clk->dev_id, sci_clk->clk_id); init.name = name; if (init.num_parents < 2) { init.num_parents = 0; init.flags = CLK_IS_ROOT; } if (init.num_parents) { parent_names = devm_kcalloc(provider->dev, init.num_parents, sizeof(char *), GFP_KERNEL); if (!parent_names) { ret = -ENOMEM; goto err; } for (i = 0; i < init.num_parents; i++) { char *parent_name; parent_name = devm_kzalloc(provider->dev, 20, GFP_KERNEL); if (!parent_name) { ret = -ENOMEM; goto err; } snprintf(parent_name, 20, "%s:%d:%d", dev_name(provider->dev), sci_clk->dev_id, sci_clk->clk_id + 1 + i); parent_names[i] = parent_name; _sci_clk_get(provider, dev_id, clk_id + 1 + i, false); } init.parent_names = (const char * const *)parent_names; } init.ops = &sci_clk_ops; sci_clk->hw.init = &init; clk = devm_clk_register(provider->dev, &sci_clk->hw); if (IS_ERR(clk)) { ret = PTR_ERR(clk); dev_err(provider->dev, "failed clk register with %d\n", ret); goto err; } else { list_add(&sci_clk->node, &provider->clocks); } return clk; err: if (parent_names) { for (i = 0; i < init.num_parents; i++) devm_kfree(provider->dev, parent_names[i]); devm_kfree(provider->dev, parent_names); } devm_kfree(provider->dev, sci_clk); return ERR_PTR(ret); } /** * 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 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 clock struct, or ERR_PTR value in failure. */ static struct clk *sci_clk_get(struct of_phandle_args *clkspec, void *data) { struct sci_clk_provider *provider = data; struct clk *clk; u16 dev_id; u8 clk_id; if (clkspec->args_count != 2) return ERR_PTR(-EINVAL); mutex_lock(&provider->lock); dev_id = clkspec->args[0]; clk_id = clkspec->args[1]; clk = _sci_clk_get(provider, dev_id, clk_id, true); mutex_unlock(&provider->lock); return clk; } static const struct of_device_id ti_sci_clk_of_match[] = { { .compatible = "ti,sci-clk" }, { /* Sentinel */ }, }; MODULE_DEVICE_TABLE(of, ti_sci_clk_of_match); /** * ti_sci_clk_parse_flags - Helper function to parse clock flag arrays * @dev: clock provider device * @np: device node pointer for the clock provider * @list_name: property name containing the clocks list * @flag: flag to apply to the list of clocks * * Parses a DT list based on the provided data, and applies the flag value * for each of the clocks identified by the list. Return 0 for success, * negative error value for failure. */ static int ti_sci_clk_parse_flags(struct device *dev, struct device_node *np, const char *list_name, u8 flag) { int num_clks; int i; num_clks = of_count_phandle_with_args(np, list_name, "#clock-cells"); for (i = 0; i < num_clks; i++) { struct of_phandle_args clkspec; struct clk_hw *hw; struct sci_clk *sci_clk; struct clk *clk; int ret; ret = of_parse_phandle_with_args(np, list_name, "#clock-cells", i, &clkspec); if (ret) { dev_err(dev, "Failed to parse %s[%d] = %d\n", list_name, i, ret); return ret; } clk = of_clk_get_from_provider(&clkspec); if (IS_ERR(clk)) { dev_err(dev, "clk_get failed for %s[%d] = %ld\n", list_name, i, PTR_ERR(clk)); return PTR_ERR(clk); } hw = __clk_get_hw(clk); sci_clk = to_sci_clk(hw); sci_clk->flags |= flag; } return 0; } /** * 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; if (!np) { dev_err(dev, "OF data missing\n"); return -EINVAL; } 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; INIT_LIST_HEAD(&provider->clocks); mutex_init(&provider->lock); provider->sci = handle; provider->ops = &handle->ops.clk_ops; provider->dev = dev; of_clk_add_provider(np, sci_clk_get, provider); ti_sci_clk_parse_flags(dev, np, "ti,ssc-clocks", SCI_CLK_SSC_ENABLE); ti_sci_clk_parse_flags(dev, np, "ti,allow-freq-change-clocks", SCI_CLK_ALLOW_FREQ_CHANGE); ti_sci_clk_parse_flags(dev, np, "ti,input-term-clocks", SCI_CLK_INPUT_TERMINATION); dev_info(dev, "initialized.\n"); return 0; } /** * 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");