linux/drivers/clk/tegra/clk-bpmp.c
Sivaram Nair a886c310d9 clk: tegra: bpmp: Clamp clock rates on requests
BPMP firmware ABI expects the rate inputs in int64_t. However,
tegra_bpmp_clk_round_rate() and tegra_bpmp_clk_set_rate() functions
directly assign 'unsigned long' inputs to a int64_t value causing
unexpected rounding errors.

Fix this by clipping the input rate to S64_MAX.

Signed-off-by: Sivaram Nair <sivaramn@nvidia.com>
[mperttunen: slight cleanup]
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Sivaram Nair <sivaramn@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-11-26 16:28:07 +01:00

629 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2016-2020 NVIDIA Corporation
*/
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/seq_buf.h>
#include <linux/slab.h>
#include <soc/tegra/bpmp.h>
#include <soc/tegra/bpmp-abi.h>
#define TEGRA_BPMP_DUMP_CLOCK_INFO 0
#define TEGRA_BPMP_CLK_HAS_MUX BIT(0)
#define TEGRA_BPMP_CLK_HAS_SET_RATE BIT(1)
#define TEGRA_BPMP_CLK_IS_ROOT BIT(2)
struct tegra_bpmp_clk_info {
unsigned int id;
char name[MRQ_CLK_NAME_MAXLEN];
unsigned int parents[MRQ_CLK_MAX_PARENTS];
unsigned int num_parents;
unsigned long flags;
};
struct tegra_bpmp_clk {
struct clk_hw hw;
struct tegra_bpmp *bpmp;
unsigned int id;
unsigned int num_parents;
unsigned int *parents;
};
static inline struct tegra_bpmp_clk *to_tegra_bpmp_clk(struct clk_hw *hw)
{
return container_of(hw, struct tegra_bpmp_clk, hw);
}
struct tegra_bpmp_clk_message {
unsigned int cmd;
unsigned int id;
struct {
const void *data;
size_t size;
} tx;
struct {
void *data;
size_t size;
int ret;
} rx;
};
static int tegra_bpmp_clk_transfer(struct tegra_bpmp *bpmp,
const struct tegra_bpmp_clk_message *clk)
{
struct mrq_clk_request request;
struct tegra_bpmp_message msg;
void *req = &request;
int err;
memset(&request, 0, sizeof(request));
request.cmd_and_id = (clk->cmd << 24) | clk->id;
/*
* The mrq_clk_request structure has an anonymous union at offset 4
* that contains all possible sub-command structures. Copy the data
* to that union. Ideally we'd be able to refer to it by name, but
* doing so would require changing the ABI header and increase the
* maintenance burden.
*/
memcpy(req + 4, clk->tx.data, clk->tx.size);
memset(&msg, 0, sizeof(msg));
msg.mrq = MRQ_CLK;
msg.tx.data = &request;
msg.tx.size = sizeof(request);
msg.rx.data = clk->rx.data;
msg.rx.size = clk->rx.size;
err = tegra_bpmp_transfer(bpmp, &msg);
if (err < 0)
return err;
else if (msg.rx.ret < 0)
return -EINVAL;
return 0;
}
static int tegra_bpmp_clk_prepare(struct clk_hw *hw)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct tegra_bpmp_clk_message msg;
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_ENABLE;
msg.id = clk->id;
return tegra_bpmp_clk_transfer(clk->bpmp, &msg);
}
static void tegra_bpmp_clk_unprepare(struct clk_hw *hw)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct tegra_bpmp_clk_message msg;
int err;
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_DISABLE;
msg.id = clk->id;
err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
if (err < 0)
dev_err(clk->bpmp->dev, "failed to disable clock %s: %d\n",
clk_hw_get_name(hw), err);
}
static int tegra_bpmp_clk_is_prepared(struct clk_hw *hw)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct cmd_clk_is_enabled_response response;
struct tegra_bpmp_clk_message msg;
int err;
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_IS_ENABLED;
msg.id = clk->id;
msg.rx.data = &response;
msg.rx.size = sizeof(response);
err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
if (err < 0)
return err;
return response.state;
}
static unsigned long tegra_bpmp_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct cmd_clk_get_rate_response response;
struct cmd_clk_get_rate_request request;
struct tegra_bpmp_clk_message msg;
int err;
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_GET_RATE;
msg.id = clk->id;
msg.tx.data = &request;
msg.tx.size = sizeof(request);
msg.rx.data = &response;
msg.rx.size = sizeof(response);
err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
if (err < 0)
return err;
return response.rate;
}
static long tegra_bpmp_clk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct cmd_clk_round_rate_response response;
struct cmd_clk_round_rate_request request;
struct tegra_bpmp_clk_message msg;
int err;
memset(&request, 0, sizeof(request));
request.rate = min_t(u64, rate, S64_MAX);
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_ROUND_RATE;
msg.id = clk->id;
msg.tx.data = &request;
msg.tx.size = sizeof(request);
msg.rx.data = &response;
msg.rx.size = sizeof(response);
err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
if (err < 0)
return err;
return response.rate;
}
static int tegra_bpmp_clk_set_parent(struct clk_hw *hw, u8 index)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct cmd_clk_set_parent_response response;
struct cmd_clk_set_parent_request request;
struct tegra_bpmp_clk_message msg;
int err;
memset(&request, 0, sizeof(request));
request.parent_id = clk->parents[index];
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_SET_PARENT;
msg.id = clk->id;
msg.tx.data = &request;
msg.tx.size = sizeof(request);
msg.rx.data = &response;
msg.rx.size = sizeof(response);
err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
if (err < 0)
return err;
/* XXX check parent ID in response */
return 0;
}
static u8 tegra_bpmp_clk_get_parent(struct clk_hw *hw)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct cmd_clk_get_parent_response response;
struct tegra_bpmp_clk_message msg;
unsigned int i;
int err;
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_GET_PARENT;
msg.id = clk->id;
msg.rx.data = &response;
msg.rx.size = sizeof(response);
err = tegra_bpmp_clk_transfer(clk->bpmp, &msg);
if (err < 0) {
dev_err(clk->bpmp->dev, "failed to get parent for %s: %d\n",
clk_hw_get_name(hw), err);
return U8_MAX;
}
for (i = 0; i < clk->num_parents; i++)
if (clk->parents[i] == response.parent_id)
return i;
return U8_MAX;
}
static int tegra_bpmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct tegra_bpmp_clk *clk = to_tegra_bpmp_clk(hw);
struct cmd_clk_set_rate_response response;
struct cmd_clk_set_rate_request request;
struct tegra_bpmp_clk_message msg;
memset(&request, 0, sizeof(request));
request.rate = min_t(u64, rate, S64_MAX);
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_SET_RATE;
msg.id = clk->id;
msg.tx.data = &request;
msg.tx.size = sizeof(request);
msg.rx.data = &response;
msg.rx.size = sizeof(response);
return tegra_bpmp_clk_transfer(clk->bpmp, &msg);
}
static const struct clk_ops tegra_bpmp_clk_gate_ops = {
.prepare = tegra_bpmp_clk_prepare,
.unprepare = tegra_bpmp_clk_unprepare,
.is_prepared = tegra_bpmp_clk_is_prepared,
.recalc_rate = tegra_bpmp_clk_recalc_rate,
};
static const struct clk_ops tegra_bpmp_clk_mux_ops = {
.prepare = tegra_bpmp_clk_prepare,
.unprepare = tegra_bpmp_clk_unprepare,
.is_prepared = tegra_bpmp_clk_is_prepared,
.recalc_rate = tegra_bpmp_clk_recalc_rate,
.set_parent = tegra_bpmp_clk_set_parent,
.get_parent = tegra_bpmp_clk_get_parent,
};
static const struct clk_ops tegra_bpmp_clk_rate_ops = {
.prepare = tegra_bpmp_clk_prepare,
.unprepare = tegra_bpmp_clk_unprepare,
.is_prepared = tegra_bpmp_clk_is_prepared,
.recalc_rate = tegra_bpmp_clk_recalc_rate,
.round_rate = tegra_bpmp_clk_round_rate,
.set_rate = tegra_bpmp_clk_set_rate,
};
static const struct clk_ops tegra_bpmp_clk_mux_rate_ops = {
.prepare = tegra_bpmp_clk_prepare,
.unprepare = tegra_bpmp_clk_unprepare,
.is_prepared = tegra_bpmp_clk_is_prepared,
.recalc_rate = tegra_bpmp_clk_recalc_rate,
.round_rate = tegra_bpmp_clk_round_rate,
.set_parent = tegra_bpmp_clk_set_parent,
.get_parent = tegra_bpmp_clk_get_parent,
.set_rate = tegra_bpmp_clk_set_rate,
};
static int tegra_bpmp_clk_get_max_id(struct tegra_bpmp *bpmp)
{
struct cmd_clk_get_max_clk_id_response response;
struct tegra_bpmp_clk_message msg;
int err;
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_GET_MAX_CLK_ID;
msg.rx.data = &response;
msg.rx.size = sizeof(response);
err = tegra_bpmp_clk_transfer(bpmp, &msg);
if (err < 0)
return err;
if (response.max_id > INT_MAX)
return -E2BIG;
return response.max_id;
}
static int tegra_bpmp_clk_get_info(struct tegra_bpmp *bpmp, unsigned int id,
struct tegra_bpmp_clk_info *info)
{
struct cmd_clk_get_all_info_response response;
struct tegra_bpmp_clk_message msg;
unsigned int i;
int err;
memset(&msg, 0, sizeof(msg));
msg.cmd = CMD_CLK_GET_ALL_INFO;
msg.id = id;
msg.rx.data = &response;
msg.rx.size = sizeof(response);
err = tegra_bpmp_clk_transfer(bpmp, &msg);
if (err < 0)
return err;
strlcpy(info->name, response.name, MRQ_CLK_NAME_MAXLEN);
info->num_parents = response.num_parents;
for (i = 0; i < info->num_parents; i++)
info->parents[i] = response.parents[i];
info->flags = response.flags;
return 0;
}
static void tegra_bpmp_clk_info_dump(struct tegra_bpmp *bpmp,
const char *level,
const struct tegra_bpmp_clk_info *info)
{
const char *prefix = "";
struct seq_buf buf;
unsigned int i;
char flags[64];
seq_buf_init(&buf, flags, sizeof(flags));
if (info->flags)
seq_buf_printf(&buf, "(");
if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
seq_buf_printf(&buf, "%smux", prefix);
prefix = ", ";
}
if ((info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE) == 0) {
seq_buf_printf(&buf, "%sfixed", prefix);
prefix = ", ";
}
if (info->flags & TEGRA_BPMP_CLK_IS_ROOT) {
seq_buf_printf(&buf, "%sroot", prefix);
prefix = ", ";
}
if (info->flags)
seq_buf_printf(&buf, ")");
dev_printk(level, bpmp->dev, "%03u: %s\n", info->id, info->name);
dev_printk(level, bpmp->dev, " flags: %lx %s\n", info->flags, flags);
dev_printk(level, bpmp->dev, " parents: %u\n", info->num_parents);
for (i = 0; i < info->num_parents; i++)
dev_printk(level, bpmp->dev, " %03u\n", info->parents[i]);
}
static int tegra_bpmp_probe_clocks(struct tegra_bpmp *bpmp,
struct tegra_bpmp_clk_info **clocksp)
{
struct tegra_bpmp_clk_info *clocks;
unsigned int max_id, id, count = 0;
unsigned int holes = 0;
int err;
err = tegra_bpmp_clk_get_max_id(bpmp);
if (err < 0)
return err;
max_id = err;
dev_dbg(bpmp->dev, "maximum clock ID: %u\n", max_id);
clocks = kcalloc(max_id + 1, sizeof(*clocks), GFP_KERNEL);
if (!clocks)
return -ENOMEM;
for (id = 0; id <= max_id; id++) {
struct tegra_bpmp_clk_info *info = &clocks[count];
err = tegra_bpmp_clk_get_info(bpmp, id, info);
if (err < 0)
continue;
if (info->num_parents >= U8_MAX) {
dev_err(bpmp->dev,
"clock %u has too many parents (%u, max: %u)\n",
id, info->num_parents, U8_MAX);
continue;
}
/* clock not exposed by BPMP */
if (info->name[0] == '\0') {
holes++;
continue;
}
info->id = id;
count++;
if (TEGRA_BPMP_DUMP_CLOCK_INFO)
tegra_bpmp_clk_info_dump(bpmp, KERN_DEBUG, info);
}
dev_dbg(bpmp->dev, "holes: %u\n", holes);
*clocksp = clocks;
return count;
}
static const struct tegra_bpmp_clk_info *
tegra_bpmp_clk_find(const struct tegra_bpmp_clk_info *clocks,
unsigned int num_clocks, unsigned int id)
{
unsigned int i;
for (i = 0; i < num_clocks; i++)
if (clocks[i].id == id)
return &clocks[i];
return NULL;
}
static struct tegra_bpmp_clk *
tegra_bpmp_clk_register(struct tegra_bpmp *bpmp,
const struct tegra_bpmp_clk_info *info,
const struct tegra_bpmp_clk_info *clocks,
unsigned int num_clocks)
{
struct tegra_bpmp_clk *clk;
struct clk_init_data init;
const char **parents;
unsigned int i;
int err;
clk = devm_kzalloc(bpmp->dev, sizeof(*clk), GFP_KERNEL);
if (!clk)
return ERR_PTR(-ENOMEM);
clk->id = info->id;
clk->bpmp = bpmp;
clk->parents = devm_kcalloc(bpmp->dev, info->num_parents,
sizeof(*clk->parents), GFP_KERNEL);
if (!clk->parents)
return ERR_PTR(-ENOMEM);
clk->num_parents = info->num_parents;
/* hardware clock initialization */
memset(&init, 0, sizeof(init));
init.name = info->name;
clk->hw.init = &init;
if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
init.ops = &tegra_bpmp_clk_mux_rate_ops;
else
init.ops = &tegra_bpmp_clk_mux_ops;
} else {
if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
init.ops = &tegra_bpmp_clk_rate_ops;
else
init.ops = &tegra_bpmp_clk_gate_ops;
}
init.num_parents = info->num_parents;
parents = kcalloc(info->num_parents, sizeof(*parents), GFP_KERNEL);
if (!parents)
return ERR_PTR(-ENOMEM);
for (i = 0; i < info->num_parents; i++) {
const struct tegra_bpmp_clk_info *parent;
/* keep a private copy of the ID to parent index map */
clk->parents[i] = info->parents[i];
parent = tegra_bpmp_clk_find(clocks, num_clocks,
info->parents[i]);
if (!parent) {
dev_err(bpmp->dev, "no parent %u found for %u\n",
info->parents[i], info->id);
continue;
}
parents[i] = parent->name;
}
init.parent_names = parents;
err = devm_clk_hw_register(bpmp->dev, &clk->hw);
kfree(parents);
if (err < 0)
return ERR_PTR(err);
return clk;
}
static int tegra_bpmp_register_clocks(struct tegra_bpmp *bpmp,
struct tegra_bpmp_clk_info *infos,
unsigned int count)
{
struct tegra_bpmp_clk *clk;
unsigned int i;
bpmp->num_clocks = count;
bpmp->clocks = devm_kcalloc(bpmp->dev, count, sizeof(clk), GFP_KERNEL);
if (!bpmp->clocks)
return -ENOMEM;
for (i = 0; i < count; i++) {
struct tegra_bpmp_clk_info *info = &infos[i];
clk = tegra_bpmp_clk_register(bpmp, info, infos, count);
if (IS_ERR(clk)) {
dev_err(bpmp->dev,
"failed to register clock %u (%s): %ld\n",
info->id, info->name, PTR_ERR(clk));
continue;
}
bpmp->clocks[i] = clk;
}
return 0;
}
static void tegra_bpmp_unregister_clocks(struct tegra_bpmp *bpmp)
{
unsigned int i;
for (i = 0; i < bpmp->num_clocks; i++)
clk_hw_unregister(&bpmp->clocks[i]->hw);
}
static struct clk_hw *tegra_bpmp_clk_of_xlate(struct of_phandle_args *clkspec,
void *data)
{
unsigned int id = clkspec->args[0], i;
struct tegra_bpmp *bpmp = data;
for (i = 0; i < bpmp->num_clocks; i++) {
struct tegra_bpmp_clk *clk = bpmp->clocks[i];
if (!clk)
continue;
if (clk->id == id)
return &clk->hw;
}
return NULL;
}
int tegra_bpmp_init_clocks(struct tegra_bpmp *bpmp)
{
struct tegra_bpmp_clk_info *clocks;
unsigned int count;
int err;
err = tegra_bpmp_probe_clocks(bpmp, &clocks);
if (err < 0)
return err;
count = err;
dev_dbg(bpmp->dev, "%u clocks probed\n", count);
err = tegra_bpmp_register_clocks(bpmp, clocks, count);
if (err < 0)
goto free;
err = of_clk_add_hw_provider(bpmp->dev->of_node,
tegra_bpmp_clk_of_xlate,
bpmp);
if (err < 0) {
tegra_bpmp_unregister_clocks(bpmp);
goto free;
}
free:
kfree(clocks);
return err;
}