2 * SCI Clock driver for keystone based devices
4 * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
5 * Tero Kristo <t-kristo@ti.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
12 * kind, whether express or implied; without even the implied warranty
13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 #include <linux/clk-provider.h>
17 #include <linux/err.h>
19 #include <linux/module.h>
20 #include <linux/of_address.h>
21 #include <linux/of_device.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
24 #include <linux/soc/ti/ti_sci_protocol.h>
26 #define SCI_CLK_SSC_ENABLE BIT(0)
27 #define SCI_CLK_ALLOW_FREQ_CHANGE BIT(1)
28 #define SCI_CLK_INPUT_TERMINATION BIT(2)
31 * struct sci_clk_data - TI SCI clock data
33 * @num_clks: number of clocks for this device
41 * struct sci_clk_provider - TI SCI clock provider representation
42 * @sci: Handle to the System Control Interface protocol handler
43 * @ops: Pointer to the SCI ops to be used by the clocks
44 * @dev: Device pointer for the clock provider
45 * @clk_data: Clock data
46 * @clocks: Clocks array for this device
48 struct sci_clk_provider {
49 const struct ti_sci_handle *sci;
50 const struct ti_sci_clk_ops *ops;
52 const struct sci_clk_data *clk_data;
53 struct clk_hw **clocks;
57 * struct sci_clk - TI SCI clock representation
58 * @hw: Hardware clock cookie for common clock framework
59 * @dev_id: Device index
60 * @clk_id: Clock index
61 * @node: Clocks list link
62 * @provider: Master clock provider
63 * @flags: Flags for the clock
69 struct list_head node;
70 struct sci_clk_provider *provider;
74 #define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw)
77 * sci_clk_prepare - Prepare (enable) a TI SCI clock
78 * @hw: clock to prepare
80 * Prepares a clock to be actively used. Returns the SCI protocol status.
82 static int sci_clk_prepare(struct clk_hw *hw)
84 struct sci_clk *clk = to_sci_clk(hw);
85 bool enable_ssc = clk->flags & SCI_CLK_SSC_ENABLE;
86 bool allow_freq_change = clk->flags & SCI_CLK_ALLOW_FREQ_CHANGE;
87 bool input_termination = clk->flags & SCI_CLK_INPUT_TERMINATION;
89 return clk->provider->ops->get_clock(clk->provider->sci, clk->dev_id,
90 clk->clk_id, enable_ssc,
96 * sci_clk_unprepare - Un-prepares (disables) a TI SCI clock
97 * @hw: clock to unprepare
99 * Un-prepares a clock from active state.
101 static void sci_clk_unprepare(struct clk_hw *hw)
103 struct sci_clk *clk = to_sci_clk(hw);
106 ret = clk->provider->ops->put_clock(clk->provider->sci, clk->dev_id,
109 dev_err(clk->provider->dev,
110 "unprepare failed for dev=%d, clk=%d, ret=%d\n",
111 clk->dev_id, clk->clk_id, ret);
115 * sci_clk_is_prepared - Check if a TI SCI clock is prepared or not
116 * @hw: clock to check status for
118 * Checks if a clock is prepared (enabled) in hardware. Returns non-zero
119 * value if clock is enabled, zero otherwise.
121 static int sci_clk_is_prepared(struct clk_hw *hw)
123 struct sci_clk *clk = to_sci_clk(hw);
124 bool req_state, current_state;
127 ret = clk->provider->ops->is_on(clk->provider->sci, clk->dev_id,
128 clk->clk_id, &req_state,
131 dev_err(clk->provider->dev,
132 "is_prepared failed for dev=%d, clk=%d, ret=%d\n",
133 clk->dev_id, clk->clk_id, ret);
141 * sci_clk_recalc_rate - Get clock rate for a TI SCI clock
142 * @hw: clock to get rate for
143 * @parent_rate: parent rate provided by common clock framework, not used
145 * Gets the current clock rate of a TI SCI clock. Returns the current
146 * clock rate, or zero in failure.
148 static unsigned long sci_clk_recalc_rate(struct clk_hw *hw,
149 unsigned long parent_rate)
151 struct sci_clk *clk = to_sci_clk(hw);
155 ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id,
158 dev_err(clk->provider->dev,
159 "recalc-rate failed for dev=%d, clk=%d, ret=%d\n",
160 clk->dev_id, clk->clk_id, ret);
168 * sci_clk_determine_rate - Determines a clock rate a clock can be set to
169 * @hw: clock to change rate for
170 * @req: requested rate configuration for the clock
172 * Determines a suitable clock rate and parent for a TI SCI clock.
173 * The parent handling is un-used, as generally the parent clock rates
174 * are not known by the kernel; instead these are internally handled
175 * by the firmware. Returns 0 on success, negative error value on failure.
177 static int sci_clk_determine_rate(struct clk_hw *hw,
178 struct clk_rate_request *req)
180 struct sci_clk *clk = to_sci_clk(hw);
184 ret = clk->provider->ops->get_best_match_freq(clk->provider->sci,
192 dev_err(clk->provider->dev,
193 "determine-rate failed for dev=%d, clk=%d, ret=%d\n",
194 clk->dev_id, clk->clk_id, ret);
198 req->rate = new_rate;
204 * sci_clk_set_rate - Set rate for a TI SCI clock
205 * @hw: clock to change rate for
206 * @rate: target rate for the clock
207 * @parent_rate: rate of the clock parent, not used for TI SCI clocks
209 * Sets a clock frequency for a TI SCI clock. Returns the TI SCI
212 static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate,
213 unsigned long parent_rate)
215 struct sci_clk *clk = to_sci_clk(hw);
217 return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
218 clk->clk_id, rate, rate, rate);
222 * sci_clk_get_parent - Get the current parent of a TI SCI clock
223 * @hw: clock to get parent for
225 * Returns the index of the currently selected parent for a TI SCI clock.
227 static u8 sci_clk_get_parent(struct clk_hw *hw)
229 struct sci_clk *clk = to_sci_clk(hw);
233 ret = clk->provider->ops->get_parent(clk->provider->sci, clk->dev_id,
234 clk->clk_id, &parent_id);
236 dev_err(clk->provider->dev,
237 "get-parent failed for dev=%d, clk=%d, ret=%d\n",
238 clk->dev_id, clk->clk_id, ret);
242 return parent_id - clk->clk_id - 1;
246 * sci_clk_set_parent - Set the parent of a TI SCI clock
247 * @hw: clock to set parent for
248 * @index: new parent index for the clock
250 * Sets the parent of a TI SCI clock. Return TI SCI protocol status.
252 static int sci_clk_set_parent(struct clk_hw *hw, u8 index)
254 struct sci_clk *clk = to_sci_clk(hw);
256 return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
258 index + 1 + clk->clk_id);
261 static const struct clk_ops sci_clk_ops = {
262 .prepare = sci_clk_prepare,
263 .unprepare = sci_clk_unprepare,
264 .is_prepared = sci_clk_is_prepared,
265 .recalc_rate = sci_clk_recalc_rate,
266 .determine_rate = sci_clk_determine_rate,
267 .set_rate = sci_clk_set_rate,
268 .get_parent = sci_clk_get_parent,
269 .set_parent = sci_clk_set_parent,
273 * _sci_clk_get - Gets a handle for an SCI clock
274 * @provider: Handle to SCI clock provider
275 * @dev_id: device ID for the clock to register
276 * @clk_id: clock ID for the clock to register
278 * Gets a handle to an existing TI SCI hw clock, or builds a new clock
279 * entry and registers it with the common clock framework. Called from
280 * the common clock framework, when a corresponding of_clk_get call is
281 * executed, or recursively from itself when parsing parent clocks.
282 * Returns a pointer to the hw clock struct, or ERR_PTR value in failure.
284 static struct clk_hw *_sci_clk_build(struct sci_clk_provider *provider,
285 u16 dev_id, u8 clk_id)
287 struct clk_init_data init = { NULL };
288 struct sci_clk *sci_clk = NULL;
290 char **parent_names = NULL;
294 sci_clk = devm_kzalloc(provider->dev, sizeof(*sci_clk), GFP_KERNEL);
296 return ERR_PTR(-ENOMEM);
298 sci_clk->dev_id = dev_id;
299 sci_clk->clk_id = clk_id;
300 sci_clk->provider = provider;
302 ret = provider->ops->get_num_parents(provider->sci, dev_id,
308 name = kasprintf(GFP_KERNEL, "%s:%d:%d", dev_name(provider->dev),
309 sci_clk->dev_id, sci_clk->clk_id);
314 * From kernel point of view, we only care about a clocks parents,
315 * if it has more than 1 possible parent. In this case, it is going
316 * to have mux functionality. Otherwise it is going to act as a root
319 if (init.num_parents < 2)
320 init.num_parents = 0;
322 if (init.num_parents) {
323 parent_names = kcalloc(init.num_parents, sizeof(char *),
331 for (i = 0; i < init.num_parents; i++) {
334 parent_name = kasprintf(GFP_KERNEL, "%s:%d:%d",
335 dev_name(provider->dev),
337 sci_clk->clk_id + 1 + i);
342 parent_names[i] = parent_name;
344 init.parent_names = (void *)parent_names;
347 init.ops = &sci_clk_ops;
348 sci_clk->hw.init = &init;
350 ret = devm_clk_hw_register(provider->dev, &sci_clk->hw);
352 dev_err(provider->dev, "failed clk register with %d\n", ret);
356 for (i = 0; i < init.num_parents; i++)
357 kfree(parent_names[i]);
371 * sci_clk_get - Xlate function for getting clock handles
372 * @clkspec: device tree clock specifier
373 * @data: pointer to the clock provider
375 * Xlate function for retrieving clock TI SCI hw clock handles based on
376 * device tree clock specifier. Called from the common clock framework,
377 * when a corresponding of_clk_get call is executed. Returns a pointer
378 * to the TI SCI hw clock struct, or ERR_PTR value in failure.
380 static struct clk_hw *sci_clk_get(struct of_phandle_args *clkspec, void *data)
382 struct sci_clk_provider *provider = data;
385 const struct sci_clk_data *clks = provider->clk_data;
386 struct clk_hw **clocks = provider->clocks;
388 if (clkspec->args_count != 2)
389 return ERR_PTR(-EINVAL);
391 dev_id = clkspec->args[0];
392 clk_id = clkspec->args[1];
394 while (clks->num_clks) {
395 if (clks->dev == dev_id) {
396 if (clk_id >= clks->num_clks)
397 return ERR_PTR(-EINVAL);
399 return clocks[clk_id];
405 return ERR_PTR(-ENODEV);
408 static int ti_sci_init_clocks(struct sci_clk_provider *p)
410 const struct sci_clk_data *data = p->clk_data;
414 while (data->num_clks) {
415 p->clocks = devm_kcalloc(p->dev, data->num_clks,
416 sizeof(struct sci_clk),
421 for (i = 0; i < data->num_clks; i++) {
422 hw = _sci_clk_build(p, data->dev, i);
428 /* Skip any holes in the clock lists */
429 if (PTR_ERR(hw) == -ENODEV)
440 static const struct sci_clk_data k2g_clk_data[] = {
442 { .dev = 0x0, .num_clks = 4 },
445 { .dev = 0x1, .num_clks = 5 },
448 { .dev = 0x2, .num_clks = 2 },
451 { .dev = 0x3, .num_clks = 8 },
454 { .dev = 0x4, .num_clks = 8 },
457 { .dev = 0x5, .num_clks = 8 },
460 { .dev = 0x6, .num_clks = 8 },
463 { .dev = 0x8, .num_clks = 2 },
466 { .dev = 0x9, .num_clks = 2 },
469 { .dev = 0xa, .num_clks = 6 },
472 { .dev = 0xb, .num_clks = 3 },
475 { .dev = 0xc, .num_clks = 3 },
478 { .dev = 0xd, .num_clks = 1 },
481 { .dev = 0xe, .num_clks = 1 },
484 { .dev = 0x10, .num_clks = 1 },
487 { .dev = 0x11, .num_clks = 1 },
490 { .dev = 0x12, .num_clks = 1 },
493 { .dev = 0x13, .num_clks = 1 },
496 { .dev = 0x14, .num_clks = 6 },
499 { .dev = 0x15, .num_clks = 6 },
502 { .dev = 0x16, .num_clks = 7 },
505 { .dev = 0x17, .num_clks = 7 },
508 { .dev = 0x18, .num_clks = 14 },
511 { .dev = 0x19, .num_clks = 1 },
514 { .dev = 0x1b, .num_clks = 1 },
517 { .dev = 0x1c, .num_clks = 1 },
520 { .dev = 0x1d, .num_clks = 9 },
523 { .dev = 0x1e, .num_clks = 9 },
526 { .dev = 0x1f, .num_clks = 9 },
529 { .dev = 0x20, .num_clks = 9 },
532 { .dev = 0x21, .num_clks = 9 },
535 { .dev = 0x22, .num_clks = 9 },
538 { .dev = 0x23, .num_clks = 9 },
541 { .dev = 0x25, .num_clks = 1 },
544 { .dev = 0x26, .num_clks = 1 },
547 { .dev = 0x27, .num_clks = 1 },
550 { .dev = 0x29, .num_clks = 1 },
553 { .dev = 0x2b, .num_clks = 8 },
556 { .dev = 0x2c, .num_clks = 1 },
559 { .dev = 0x2d, .num_clks = 1 },
562 { .dev = 0x2e, .num_clks = 1 },
565 { .dev = 0x2f, .num_clks = 1 },
568 { .dev = 0x30, .num_clks = 1 },
571 { .dev = 0x31, .num_clks = 1 },
574 { .dev = 0x32, .num_clks = 1 },
577 { .dev = 0x33, .num_clks = 1 },
580 { .dev = 0x34, .num_clks = 1 },
583 { .dev = 0x35, .num_clks = 1 },
586 { .dev = 0x36, .num_clks = 1 },
589 { .dev = 0x37, .num_clks = 1 },
592 { .dev = 0x38, .num_clks = 1 },
595 { .dev = 0x39, .num_clks = 1 },
598 { .dev = 0x3a, .num_clks = 1 },
601 { .dev = 0x3b, .num_clks = 1 },
604 { .dev = 0x3c, .num_clks = 1 },
607 { .dev = 0x3f, .num_clks = 2 },
610 { .dev = 0x40, .num_clks = 1 },
613 { .dev = 0x41, .num_clks = 1 },
616 { .dev = 0x42, .num_clks = 1 },
619 { .dev = 0x43, .num_clks = 5 },
621 /* arm_64b_counter0 */
622 { .dev = 0x44, .num_clks = 2 },
625 { .dev = 0x45, .num_clks = 2 },
628 { .dev = 0x46, .num_clks = 2 },
631 { .dev = 0x47, .num_clks = 1 },
634 { .dev = 0x49, .num_clks = 1 },
637 { .dev = 0x4c, .num_clks = 36 },
640 { .dev = 0x4f, .num_clks = 2 },
644 static const struct of_device_id ti_sci_clk_of_match[] = {
645 { .compatible = "ti,k2g-sci-clk", .data = &k2g_clk_data },
648 MODULE_DEVICE_TABLE(of, ti_sci_clk_of_match);
651 * ti_sci_clk_probe - Probe function for the TI SCI clock driver
652 * @pdev: platform device pointer to be probed
654 * Probes the TI SCI clock device. Allocates a new clock provider
655 * and registers this to the common clock framework. Also applies
656 * any required flags to the identified clocks via clock lists
657 * supplied from DT. Returns 0 for success, negative error value
660 static int ti_sci_clk_probe(struct platform_device *pdev)
662 struct device *dev = &pdev->dev;
663 struct device_node *np = dev->of_node;
664 struct sci_clk_provider *provider;
665 const struct ti_sci_handle *handle;
666 const struct sci_clk_data *data;
669 data = of_device_get_match_data(dev);
673 handle = devm_ti_sci_get_handle(dev);
675 return PTR_ERR(handle);
677 provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
681 provider->clk_data = data;
683 provider->sci = handle;
684 provider->ops = &handle->ops.clk_ops;
687 ret = ti_sci_init_clocks(provider);
689 pr_err("ti-sci-init-clocks failed.\n");
693 return of_clk_add_hw_provider(np, sci_clk_get, provider);
697 * ti_sci_clk_remove - Remove TI SCI clock device
698 * @pdev: platform device pointer for the device to be removed
700 * Removes the TI SCI device. Unregisters the clock provider registered
701 * via common clock framework. Any memory allocated for the device will
702 * be free'd silently via the devm framework. Returns 0 always.
704 static int ti_sci_clk_remove(struct platform_device *pdev)
706 of_clk_del_provider(pdev->dev.of_node);
711 static struct platform_driver ti_sci_clk_driver = {
712 .probe = ti_sci_clk_probe,
713 .remove = ti_sci_clk_remove,
715 .name = "ti-sci-clk",
716 .of_match_table = of_match_ptr(ti_sci_clk_of_match),
719 module_platform_driver(ti_sci_clk_driver);
721 MODULE_LICENSE("GPL v2");
722 MODULE_DESCRIPTION("TI System Control Interface(SCI) Clock driver");
723 MODULE_AUTHOR("Tero Kristo");
724 MODULE_ALIAS("platform:ti-sci-clk");