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linux/drivers/clk/keystone/sci-clk.c
Tero Kristo f54d2cd3c1 clk: keystone: sci-clk: Fix sci_clk_get 
Currently a bug in the sci_clk_get implementation causes it to always
return a clock belonging to the last device in the static list of clock
data. This is due to a bug in the init code that causes the array
used by sci_clk_get to only be populated with the clocks for the last
device, as each device overwrites the entire array with its own clocks.

Fix this by calculating the actual number of clocks for the SoC, and
allocating the whole array in one go. Also, we don't need the handle
to the init data array anymore after doing this, instead we can
just compare the dev_id / clk_id against the registered clocks and
use binary search for speed.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reported-by: Dave Gerlach <d-gerlach@ti.com>
Fixes: b745c0794e ("clk: keystone: Add sci-clk driver support")
Cc: Nishanth Menon <nm@ti.com>
Tested-by: Franklin Cooper <fcooper@ti.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-08-02 18:37:26 -07:00

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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_data - TI SCI clock data
* @dev: device index
* @num_clks: number of clocks for this device
*/
struct sci_clk_data {
u16 dev;
u16 num_clks;
};
/**
* 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
* @clk_data: Clock data
* @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;
const struct sci_clk_data *clk_data;
struct clk_hw **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
* @provider: Master clock provider
* @flags: Flags for the clock
*/
struct sci_clk {
struct clk_hw hw;
u16 dev_id;
u8 clk_id;
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
* @dev_id: device ID for the clock to register
* @clk_id: clock ID for the clock to register
*
* 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 a pointer to the hw clock struct, or ERR_PTR value in failure.
*/
static struct clk_hw *_sci_clk_build(struct sci_clk_provider *provider,
u16 dev_id, u8 clk_id)
{
struct clk_init_data init = { NULL };
struct sci_clk *sci_clk = NULL;
char *name = NULL;
char **parent_names = NULL;
int i;
int ret;
sci_clk = devm_kzalloc(provider->dev, sizeof(*sci_clk), GFP_KERNEL);
if (!sci_clk)
return ERR_PTR(-ENOMEM);
sci_clk->dev_id = dev_id;
sci_clk->clk_id = clk_id;
sci_clk->provider = provider;
ret = provider->ops->get_num_parents(provider->sci, dev_id,
clk_id,
&init.num_parents);
if (ret)
goto err;
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 (init.num_parents < 2)
init.num_parents = 0;
if (init.num_parents) {
parent_names = kcalloc(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 = 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;
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 < init.num_parents; i++)
kfree(parent_names[i]);
kfree(parent_names);
}
kfree(name);
if (ret)
return ERR_PTR(ret);
return &sci_clk->hw;
}
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)
{
const struct sci_clk_data *data = p->clk_data;
struct clk_hw *hw;
int i;
int num_clks = 0;
while (data->num_clks) {
num_clks += data->num_clks;
data++;
}
p->num_clocks = num_clks;
p->clocks = devm_kcalloc(p->dev, num_clks, sizeof(struct sci_clk),
GFP_KERNEL);
if (!p->clocks)
return -ENOMEM;
num_clks = 0;
data = p->clk_data;
while (data->num_clks) {
for (i = 0; i < data->num_clks; i++) {
hw = _sci_clk_build(p, data->dev, i);
if (!IS_ERR(hw)) {
p->clocks[num_clks++] = hw;
continue;
}
/* Skip any holes in the clock lists */
if (PTR_ERR(hw) == -ENODEV)
continue;
return PTR_ERR(hw);
}
data++;
}
return 0;
}
static const struct sci_clk_data k2g_clk_data[] = {
/* pmmc */
{ .dev = 0x0, .num_clks = 4 },
/* mlb0 */
{ .dev = 0x1, .num_clks = 5 },
/* dss0 */
{ .dev = 0x2, .num_clks = 2 },
/* mcbsp0 */
{ .dev = 0x3, .num_clks = 8 },
/* mcasp0 */
{ .dev = 0x4, .num_clks = 8 },
/* mcasp1 */
{ .dev = 0x5, .num_clks = 8 },
/* mcasp2 */
{ .dev = 0x6, .num_clks = 8 },
/* dcan0 */
{ .dev = 0x8, .num_clks = 2 },
/* dcan1 */
{ .dev = 0x9, .num_clks = 2 },
/* emif0 */
{ .dev = 0xa, .num_clks = 6 },
/* mmchs0 */
{ .dev = 0xb, .num_clks = 3 },
/* mmchs1 */
{ .dev = 0xc, .num_clks = 3 },
/* gpmc0 */
{ .dev = 0xd, .num_clks = 1 },
/* elm0 */
{ .dev = 0xe, .num_clks = 1 },
/* spi0 */
{ .dev = 0x10, .num_clks = 1 },
/* spi1 */
{ .dev = 0x11, .num_clks = 1 },
/* spi2 */
{ .dev = 0x12, .num_clks = 1 },
/* spi3 */
{ .dev = 0x13, .num_clks = 1 },
/* icss0 */
{ .dev = 0x14, .num_clks = 6 },
/* icss1 */
{ .dev = 0x15, .num_clks = 6 },
/* usb0 */
{ .dev = 0x16, .num_clks = 7 },
/* usb1 */
{ .dev = 0x17, .num_clks = 7 },
/* nss0 */
{ .dev = 0x18, .num_clks = 14 },
/* pcie0 */
{ .dev = 0x19, .num_clks = 1 },
/* gpio0 */
{ .dev = 0x1b, .num_clks = 1 },
/* gpio1 */
{ .dev = 0x1c, .num_clks = 1 },
/* timer64_0 */
{ .dev = 0x1d, .num_clks = 9 },
/* timer64_1 */
{ .dev = 0x1e, .num_clks = 9 },
/* timer64_2 */
{ .dev = 0x1f, .num_clks = 9 },
/* timer64_3 */
{ .dev = 0x20, .num_clks = 9 },
/* timer64_4 */
{ .dev = 0x21, .num_clks = 9 },
/* timer64_5 */
{ .dev = 0x22, .num_clks = 9 },
/* timer64_6 */
{ .dev = 0x23, .num_clks = 9 },
/* msgmgr0 */
{ .dev = 0x25, .num_clks = 1 },
/* bootcfg0 */
{ .dev = 0x26, .num_clks = 1 },
/* arm_bootrom0 */
{ .dev = 0x27, .num_clks = 1 },
/* dsp_bootrom0 */
{ .dev = 0x29, .num_clks = 1 },
/* debugss0 */
{ .dev = 0x2b, .num_clks = 8 },
/* uart0 */
{ .dev = 0x2c, .num_clks = 1 },
/* uart1 */
{ .dev = 0x2d, .num_clks = 1 },
/* uart2 */
{ .dev = 0x2e, .num_clks = 1 },
/* ehrpwm0 */
{ .dev = 0x2f, .num_clks = 1 },
/* ehrpwm1 */
{ .dev = 0x30, .num_clks = 1 },
/* ehrpwm2 */
{ .dev = 0x31, .num_clks = 1 },
/* ehrpwm3 */
{ .dev = 0x32, .num_clks = 1 },
/* ehrpwm4 */
{ .dev = 0x33, .num_clks = 1 },
/* ehrpwm5 */
{ .dev = 0x34, .num_clks = 1 },
/* eqep0 */
{ .dev = 0x35, .num_clks = 1 },
/* eqep1 */
{ .dev = 0x36, .num_clks = 1 },
/* eqep2 */
{ .dev = 0x37, .num_clks = 1 },
/* ecap0 */
{ .dev = 0x38, .num_clks = 1 },
/* ecap1 */
{ .dev = 0x39, .num_clks = 1 },
/* i2c0 */
{ .dev = 0x3a, .num_clks = 1 },
/* i2c1 */
{ .dev = 0x3b, .num_clks = 1 },
/* i2c2 */
{ .dev = 0x3c, .num_clks = 1 },
/* edma0 */
{ .dev = 0x3f, .num_clks = 2 },
/* semaphore0 */
{ .dev = 0x40, .num_clks = 1 },
/* intc0 */
{ .dev = 0x41, .num_clks = 1 },
/* gic0 */
{ .dev = 0x42, .num_clks = 1 },
/* qspi0 */
{ .dev = 0x43, .num_clks = 5 },
/* arm_64b_counter0 */
{ .dev = 0x44, .num_clks = 2 },
/* tetris0 */
{ .dev = 0x45, .num_clks = 2 },
/* cgem0 */
{ .dev = 0x46, .num_clks = 2 },
/* msmc0 */
{ .dev = 0x47, .num_clks = 1 },
/* cbass0 */
{ .dev = 0x49, .num_clks = 1 },
/* board0 */
{ .dev = 0x4c, .num_clks = 36 },
/* edma1 */
{ .dev = 0x4f, .num_clks = 2 },
{ .num_clks = 0 },
};
static const struct of_device_id ti_sci_clk_of_match[] = {
{ .compatible = "ti,k2g-sci-clk", .data = &k2g_clk_data },
{ /* 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;
const struct sci_clk_data *data;
int ret;
data = of_device_get_match_data(dev);
if (!data)
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;
provider->clk_data = data;
provider->sci = handle;
provider->ops = &handle->ops.clk_ops;
provider->dev = dev;
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");
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