linux/drivers/firmware/arm_scmi/clock.c
Sudeep Holla aa90ac45bc firmware: arm_scmi: Use {get,put}_unaligned_le{32,64} accessors
Instead of type-casting the {tx,rx}.buf all over the place while
accessing them to read/write __le{32,64} from/to the firmware, let's
use the existing {get,put}_unaligned_le{32,64} accessors to hide all
the type cast ugliness.

Suggested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-08-12 12:23:01 +01:00

355 lines
8.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface (SCMI) Clock Protocol
*
* Copyright (C) 2018 ARM Ltd.
*/
#include "common.h"
enum scmi_clock_protocol_cmd {
CLOCK_ATTRIBUTES = 0x3,
CLOCK_DESCRIBE_RATES = 0x4,
CLOCK_RATE_SET = 0x5,
CLOCK_RATE_GET = 0x6,
CLOCK_CONFIG_SET = 0x7,
};
struct scmi_msg_resp_clock_protocol_attributes {
__le16 num_clocks;
u8 max_async_req;
u8 reserved;
};
struct scmi_msg_resp_clock_attributes {
__le32 attributes;
#define CLOCK_ENABLE BIT(0)
u8 name[SCMI_MAX_STR_SIZE];
};
struct scmi_clock_set_config {
__le32 id;
__le32 attributes;
};
struct scmi_msg_clock_describe_rates {
__le32 id;
__le32 rate_index;
};
struct scmi_msg_resp_clock_describe_rates {
__le32 num_rates_flags;
#define NUM_RETURNED(x) ((x) & 0xfff)
#define RATE_DISCRETE(x) !((x) & BIT(12))
#define NUM_REMAINING(x) ((x) >> 16)
struct {
__le32 value_low;
__le32 value_high;
} rate[0];
#define RATE_TO_U64(X) \
({ \
typeof(X) x = (X); \
le32_to_cpu((x).value_low) | (u64)le32_to_cpu((x).value_high) << 32; \
})
};
struct scmi_clock_set_rate {
__le32 flags;
#define CLOCK_SET_ASYNC BIT(0)
#define CLOCK_SET_IGNORE_RESP BIT(1)
#define CLOCK_SET_ROUND_UP BIT(2)
#define CLOCK_SET_ROUND_AUTO BIT(3)
__le32 id;
__le32 value_low;
__le32 value_high;
};
struct clock_info {
int num_clocks;
int max_async_req;
atomic_t cur_async_req;
struct scmi_clock_info *clk;
};
static int scmi_clock_protocol_attributes_get(const struct scmi_handle *handle,
struct clock_info *ci)
{
int ret;
struct scmi_xfer *t;
struct scmi_msg_resp_clock_protocol_attributes *attr;
ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
SCMI_PROTOCOL_CLOCK, 0, sizeof(*attr), &t);
if (ret)
return ret;
attr = t->rx.buf;
ret = scmi_do_xfer(handle, t);
if (!ret) {
ci->num_clocks = le16_to_cpu(attr->num_clocks);
ci->max_async_req = attr->max_async_req;
}
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_clock_attributes_get(const struct scmi_handle *handle,
u32 clk_id, struct scmi_clock_info *clk)
{
int ret;
struct scmi_xfer *t;
struct scmi_msg_resp_clock_attributes *attr;
ret = scmi_xfer_get_init(handle, CLOCK_ATTRIBUTES, SCMI_PROTOCOL_CLOCK,
sizeof(clk_id), sizeof(*attr), &t);
if (ret)
return ret;
put_unaligned_le32(clk_id, t->tx.buf);
attr = t->rx.buf;
ret = scmi_do_xfer(handle, t);
if (!ret)
strlcpy(clk->name, attr->name, SCMI_MAX_STR_SIZE);
else
clk->name[0] = '\0';
scmi_xfer_put(handle, t);
return ret;
}
static int
scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
struct scmi_clock_info *clk)
{
u64 *rate;
int ret, cnt;
bool rate_discrete = false;
u32 tot_rate_cnt = 0, rates_flag;
u16 num_returned, num_remaining;
struct scmi_xfer *t;
struct scmi_msg_clock_describe_rates *clk_desc;
struct scmi_msg_resp_clock_describe_rates *rlist;
ret = scmi_xfer_get_init(handle, CLOCK_DESCRIBE_RATES,
SCMI_PROTOCOL_CLOCK, sizeof(*clk_desc), 0, &t);
if (ret)
return ret;
clk_desc = t->tx.buf;
rlist = t->rx.buf;
do {
clk_desc->id = cpu_to_le32(clk_id);
/* Set the number of rates to be skipped/already read */
clk_desc->rate_index = cpu_to_le32(tot_rate_cnt);
ret = scmi_do_xfer(handle, t);
if (ret)
goto err;
rates_flag = le32_to_cpu(rlist->num_rates_flags);
num_remaining = NUM_REMAINING(rates_flag);
rate_discrete = RATE_DISCRETE(rates_flag);
num_returned = NUM_RETURNED(rates_flag);
if (tot_rate_cnt + num_returned > SCMI_MAX_NUM_RATES) {
dev_err(handle->dev, "No. of rates > MAX_NUM_RATES");
break;
}
if (!rate_discrete) {
clk->range.min_rate = RATE_TO_U64(rlist->rate[0]);
clk->range.max_rate = RATE_TO_U64(rlist->rate[1]);
clk->range.step_size = RATE_TO_U64(rlist->rate[2]);
dev_dbg(handle->dev, "Min %llu Max %llu Step %llu Hz\n",
clk->range.min_rate, clk->range.max_rate,
clk->range.step_size);
break;
}
rate = &clk->list.rates[tot_rate_cnt];
for (cnt = 0; cnt < num_returned; cnt++, rate++) {
*rate = RATE_TO_U64(rlist->rate[cnt]);
dev_dbg(handle->dev, "Rate %llu Hz\n", *rate);
}
tot_rate_cnt += num_returned;
/*
* check for both returned and remaining to avoid infinite
* loop due to buggy firmware
*/
} while (num_returned && num_remaining);
if (rate_discrete)
clk->list.num_rates = tot_rate_cnt;
clk->rate_discrete = rate_discrete;
err:
scmi_xfer_put(handle, t);
return ret;
}
static int
scmi_clock_rate_get(const struct scmi_handle *handle, u32 clk_id, u64 *value)
{
int ret;
struct scmi_xfer *t;
ret = scmi_xfer_get_init(handle, CLOCK_RATE_GET, SCMI_PROTOCOL_CLOCK,
sizeof(__le32), sizeof(u64), &t);
if (ret)
return ret;
put_unaligned_le32(clk_id, t->tx.buf);
ret = scmi_do_xfer(handle, t);
if (!ret)
*value = get_unaligned_le64(t->rx.buf);
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_clock_rate_set(const struct scmi_handle *handle, u32 clk_id,
u64 rate)
{
int ret;
u32 flags = 0;
struct scmi_xfer *t;
struct scmi_clock_set_rate *cfg;
struct clock_info *ci = handle->clk_priv;
ret = scmi_xfer_get_init(handle, CLOCK_RATE_SET, SCMI_PROTOCOL_CLOCK,
sizeof(*cfg), 0, &t);
if (ret)
return ret;
if (ci->max_async_req &&
atomic_inc_return(&ci->cur_async_req) < ci->max_async_req)
flags |= CLOCK_SET_ASYNC;
cfg = t->tx.buf;
cfg->flags = cpu_to_le32(flags);
cfg->id = cpu_to_le32(clk_id);
cfg->value_low = cpu_to_le32(rate & 0xffffffff);
cfg->value_high = cpu_to_le32(rate >> 32);
if (flags & CLOCK_SET_ASYNC)
ret = scmi_do_xfer_with_response(handle, t);
else
ret = scmi_do_xfer(handle, t);
if (ci->max_async_req)
atomic_dec(&ci->cur_async_req);
scmi_xfer_put(handle, t);
return ret;
}
static int
scmi_clock_config_set(const struct scmi_handle *handle, u32 clk_id, u32 config)
{
int ret;
struct scmi_xfer *t;
struct scmi_clock_set_config *cfg;
ret = scmi_xfer_get_init(handle, CLOCK_CONFIG_SET, SCMI_PROTOCOL_CLOCK,
sizeof(*cfg), 0, &t);
if (ret)
return ret;
cfg = t->tx.buf;
cfg->id = cpu_to_le32(clk_id);
cfg->attributes = cpu_to_le32(config);
ret = scmi_do_xfer(handle, t);
scmi_xfer_put(handle, t);
return ret;
}
static int scmi_clock_enable(const struct scmi_handle *handle, u32 clk_id)
{
return scmi_clock_config_set(handle, clk_id, CLOCK_ENABLE);
}
static int scmi_clock_disable(const struct scmi_handle *handle, u32 clk_id)
{
return scmi_clock_config_set(handle, clk_id, 0);
}
static int scmi_clock_count_get(const struct scmi_handle *handle)
{
struct clock_info *ci = handle->clk_priv;
return ci->num_clocks;
}
static const struct scmi_clock_info *
scmi_clock_info_get(const struct scmi_handle *handle, u32 clk_id)
{
struct clock_info *ci = handle->clk_priv;
struct scmi_clock_info *clk = ci->clk + clk_id;
if (!clk->name[0])
return NULL;
return clk;
}
static struct scmi_clk_ops clk_ops = {
.count_get = scmi_clock_count_get,
.info_get = scmi_clock_info_get,
.rate_get = scmi_clock_rate_get,
.rate_set = scmi_clock_rate_set,
.enable = scmi_clock_enable,
.disable = scmi_clock_disable,
};
static int scmi_clock_protocol_init(struct scmi_handle *handle)
{
u32 version;
int clkid, ret;
struct clock_info *cinfo;
scmi_version_get(handle, SCMI_PROTOCOL_CLOCK, &version);
dev_dbg(handle->dev, "Clock Version %d.%d\n",
PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
cinfo = devm_kzalloc(handle->dev, sizeof(*cinfo), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
scmi_clock_protocol_attributes_get(handle, cinfo);
cinfo->clk = devm_kcalloc(handle->dev, cinfo->num_clocks,
sizeof(*cinfo->clk), GFP_KERNEL);
if (!cinfo->clk)
return -ENOMEM;
for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
struct scmi_clock_info *clk = cinfo->clk + clkid;
ret = scmi_clock_attributes_get(handle, clkid, clk);
if (!ret)
scmi_clock_describe_rates_get(handle, clkid, clk);
}
handle->clk_ops = &clk_ops;
handle->clk_priv = cinfo;
return 0;
}
static int __init scmi_clock_init(void)
{
return scmi_protocol_register(SCMI_PROTOCOL_CLOCK,
&scmi_clock_protocol_init);
}
subsys_initcall(scmi_clock_init);