diff options
Diffstat (limited to 'drivers/clk/qcom/clk-smd-rpm.c')
-rw-r--r-- | drivers/clk/qcom/clk-smd-rpm.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-smd-rpm.c b/drivers/clk/qcom/clk-smd-rpm.c new file mode 100644 index 000000000000..859b709385f6 --- /dev/null +++ b/drivers/clk/qcom/clk-smd-rpm.c @@ -0,0 +1,261 @@ +/* + * Copyright (c) 2015, Linaro Limited + * Copyright (c) 2014, The Linux Foundation. All rights reserved. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; 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/export.h> +#include <linux/kernel.h> +#include <linux/mutex.h> +#include <linux/soc/qcom/smd-rpm.h> + +#include "clk-smd-rpm.h" + +#define to_clk_smd_rpm(_hw) container_of(_hw, struct clk_smd_rpm, hw) + +static DEFINE_MUTEX(rpm_clk_lock); + +static int clk_smd_rpm_set_rate_active(struct clk_smd_rpm *r, + unsigned long value) +{ + struct clk_smd_rpm_req req = { + .key = r->rpm_key, + .nbytes = sizeof(u32), + .value = DIV_ROUND_UP(value, 1000), /* RPM expects kHz */ + }; + + return qcom_rpm_smd_write(r->rpm, QCOM_SMD_RPM_ACTIVE_STATE, + r->rpm_res_type, r->rpm_clk_id, &req, + sizeof(req)); +} + +static int clk_smd_rpm_set_rate_sleep(struct clk_smd_rpm *r, + unsigned long value) +{ + struct clk_smd_rpm_req req = { + .key = r->rpm_key, + .nbytes = sizeof(u32), + .value = DIV_ROUND_UP(value, 1000), /* RPM expects kHz */ + }; + + return qcom_rpm_smd_write(r->rpm, QCOM_SMD_RPM_SLEEP_STATE, + r->rpm_res_type, r->rpm_clk_id, &req, + sizeof(req)); +} + +static void to_active_sleep(struct clk_smd_rpm *r, unsigned long rate, + unsigned long *active, unsigned long *sleep) +{ + *active = rate; + + /* + * Active-only clocks don't care what the rate is during sleep. So, + * they vote for zero. + */ + if (r->active_only) + *sleep = 0; + else + *sleep = *active; +} + +static int clk_smd_rpm_prepare(struct clk_hw *hw) +{ + struct clk_smd_rpm *r = to_clk_smd_rpm(hw); + struct clk_smd_rpm *peer = r->peer; + unsigned long this_rate = 0, this_sleep_rate = 0; + unsigned long peer_rate = 0, peer_sleep_rate = 0; + unsigned long active_rate, sleep_rate; + int ret = 0; + + mutex_lock(&rpm_clk_lock); + + /* Don't send requests to the RPM if the rate has not been set. */ + if (!r->rate) + goto out; + + to_active_sleep(r, r->rate, &this_rate, &this_sleep_rate); + + /* Take peer clock's rate into account only if it's enabled. */ + if (peer->enabled) + to_active_sleep(peer, peer->rate, + &peer_rate, &peer_sleep_rate); + + active_rate = max(this_rate, peer_rate); + + if (r->branch) + active_rate = !!active_rate; + + ret = clk_smd_rpm_set_rate_active(r, active_rate); + if (ret) + goto out; + + sleep_rate = max(this_sleep_rate, peer_sleep_rate); + if (r->branch) + sleep_rate = !!sleep_rate; + + ret = clk_smd_rpm_set_rate_sleep(r, sleep_rate); + if (ret) + /* Undo the active set vote and restore it */ + ret = clk_smd_rpm_set_rate_active(r, peer_rate); + +out: + if (!ret) + r->enabled = true; + + mutex_unlock(&rpm_clk_lock); + + return ret; +} + +static void clk_smd_rpm_unprepare(struct clk_hw *hw) +{ + struct clk_smd_rpm *r = to_clk_smd_rpm(hw); + + mutex_lock(&rpm_clk_lock); + + if (r->rate) { + struct clk_smd_rpm *peer = r->peer; + unsigned long peer_rate = 0, peer_sleep_rate = 0; + unsigned long active_rate, sleep_rate; + int ret; + + /* Take peer clock's rate into account only if it's enabled. */ + if (peer->enabled) + to_active_sleep(peer, peer->rate, &peer_rate, + &peer_sleep_rate); + + active_rate = r->branch ? !!peer_rate : peer_rate; + ret = clk_smd_rpm_set_rate_active(r, active_rate); + if (ret) + goto out; + + sleep_rate = r->branch ? !!peer_sleep_rate : peer_sleep_rate; + ret = clk_smd_rpm_set_rate_sleep(r, sleep_rate); + if (ret) + goto out; + } + r->enabled = false; + +out: + mutex_unlock(&rpm_clk_lock); +} + +static int clk_smd_rpm_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_smd_rpm *r = to_clk_smd_rpm(hw); + int ret = 0; + + mutex_lock(&rpm_clk_lock); + + if (r->enabled) { + struct clk_smd_rpm *peer = r->peer; + unsigned long active_rate, sleep_rate; + unsigned long this_rate = 0, this_sleep_rate = 0; + unsigned long peer_rate = 0, peer_sleep_rate = 0; + + to_active_sleep(r, rate, &this_rate, &this_sleep_rate); + + /* Take peer clock's rate into account only if it's enabled. */ + if (peer->enabled) + to_active_sleep(peer, peer->rate, + &peer_rate, &peer_sleep_rate); + + active_rate = max(this_rate, peer_rate); + ret = clk_smd_rpm_set_rate_active(r, active_rate); + if (ret) + goto out; + + sleep_rate = max(this_sleep_rate, peer_sleep_rate); + ret = clk_smd_rpm_set_rate_sleep(r, sleep_rate); + if (ret) + goto out; + } + r->rate = rate; +out: + mutex_unlock(&rpm_clk_lock); + + return ret; +} + +static long clk_smd_rpm_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + + /* + * RPM handles rate rounding and we don't have a way to + * know what the rate will be, so just return whatever + * rate is requested. + */ + return rate; +} + +static unsigned long clk_smd_rpm_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_smd_rpm *r = to_clk_smd_rpm(hw); + + /* + * RPM handles rate rounding and we don't have a way to + * know what the rate will be, so just return whatever + * rate was set. + */ + return r->rate; +} + +int clk_smd_rpm_enable_scaling(struct qcom_smd_rpm *rpm) +{ + int ret; + struct clk_smd_rpm_req req = { + .key = QCOM_RPM_SMD_KEY_ENABLE, + .nbytes = sizeof(u32), + .value = 1, + }; + + ret = qcom_rpm_smd_write(rpm, QCOM_SMD_RPM_SLEEP_STATE, + QCOM_SMD_RPM_MISC_CLK, + QCOM_RPM_SCALING_ENABLE_ID, &req, sizeof(req)); + if (ret) { + pr_err("RPM clock scaling (sleep set) not enabled!\n"); + return ret; + } + + ret = qcom_rpm_smd_write(rpm, QCOM_SMD_RPM_ACTIVE_STATE, + QCOM_SMD_RPM_MISC_CLK, + QCOM_RPM_SCALING_ENABLE_ID, &req, sizeof(req)); + if (ret) { + pr_err("RPM clock scaling (active set) not enabled!\n"); + return ret; + } + + pr_debug("%s: RPM clock scaling is enabled\n", __func__); + return 0; +} +EXPORT_SYMBOL_GPL(clk_smd_rpm_enable_scaling); + +const struct clk_ops clk_smd_rpm_ops = { + .prepare = clk_smd_rpm_prepare, + .unprepare = clk_smd_rpm_unprepare, + .set_rate = clk_smd_rpm_set_rate, + .round_rate = clk_smd_rpm_round_rate, + .recalc_rate = clk_smd_rpm_recalc_rate, +}; +EXPORT_SYMBOL_GPL(clk_smd_rpm_ops); + +const struct clk_ops clk_smd_rpm_branch_ops = { + .prepare = clk_smd_rpm_prepare, + .unprepare = clk_smd_rpm_unprepare, + .round_rate = clk_smd_rpm_round_rate, + .recalc_rate = clk_smd_rpm_recalc_rate, +}; +EXPORT_SYMBOL_GPL(clk_smd_rpm_branch_ops); |