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/*
* 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>
#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
*/
struct sci_clk {
struct clk_hw hw;
u16 dev_id;
u8 clk_id;
u8 num_parents;
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,
&current_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);
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;
}
return parent_id - clk->clk_id - 1;
}
/**
* 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, "%s:%d:%d", dev_name(provider->dev),
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, "%s:%d:%d",
dev_name(provider->dev),
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);
/**
* 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;
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;
u8 num_parents;
int gap_size = 0;
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;
while (1) {
ret = provider->ops->get_num_parents(provider->sci, dev_id,
clk_id, &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);
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");