swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 1c163f4c7b3f621efff9b28a47abb36f7378d783 authored by Linus Torvalds on 03 March 2019, 23:21:29 UTC
Linux 5.0
Linux 5.0
Tip revision: 1c163f4
clk-scu.c
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2018 NXP
* Dong Aisheng <aisheng.dong@nxp.com>
*/
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/slab.h>
#include "clk-scu.h"
static struct imx_sc_ipc *ccm_ipc_handle;
/*
* struct clk_scu - Description of one SCU clock
* @hw: the common clk_hw
* @rsrc_id: resource ID of this SCU clock
* @clk_type: type of this clock resource
*/
struct clk_scu {
struct clk_hw hw;
u16 rsrc_id;
u8 clk_type;
};
/*
* struct imx_sc_msg_req_set_clock_rate - clock set rate protocol
* @hdr: SCU protocol header
* @rate: rate to set
* @resource: clock resource to set rate
* @clk: clk type of this resource
*
* This structure describes the SCU protocol of clock rate set
*/
struct imx_sc_msg_req_set_clock_rate {
struct imx_sc_rpc_msg hdr;
__le32 rate;
__le16 resource;
u8 clk;
} __packed;
struct req_get_clock_rate {
__le16 resource;
u8 clk;
} __packed;
struct resp_get_clock_rate {
__le32 rate;
};
/*
* struct imx_sc_msg_get_clock_rate - clock get rate protocol
* @hdr: SCU protocol header
* @req: get rate request protocol
* @resp: get rate response protocol
*
* This structure describes the SCU protocol of clock rate get
*/
struct imx_sc_msg_get_clock_rate {
struct imx_sc_rpc_msg hdr;
union {
struct req_get_clock_rate req;
struct resp_get_clock_rate resp;
} data;
};
/*
* struct imx_sc_msg_req_clock_enable - clock gate protocol
* @hdr: SCU protocol header
* @resource: clock resource to gate
* @clk: clk type of this resource
* @enable: whether gate off the clock
* @autog: HW auto gate enable
*
* This structure describes the SCU protocol of clock gate
*/
struct imx_sc_msg_req_clock_enable {
struct imx_sc_rpc_msg hdr;
__le16 resource;
u8 clk;
u8 enable;
u8 autog;
} __packed;
static inline struct clk_scu *to_clk_scu(struct clk_hw *hw)
{
return container_of(hw, struct clk_scu, hw);
}
int imx_clk_scu_init(void)
{
return imx_scu_get_handle(&ccm_ipc_handle);
}
/*
* clk_scu_recalc_rate - Get clock rate for a SCU 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 SCU clock. Returns the current
* clock rate, or zero in failure.
*/
static unsigned long clk_scu_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_scu *clk = to_clk_scu(hw);
struct imx_sc_msg_get_clock_rate msg;
struct imx_sc_rpc_msg *hdr = &msg.hdr;
int ret;
hdr->ver = IMX_SC_RPC_VERSION;
hdr->svc = IMX_SC_RPC_SVC_PM;
hdr->func = IMX_SC_PM_FUNC_GET_CLOCK_RATE;
hdr->size = 2;
msg.data.req.resource = cpu_to_le16(clk->rsrc_id);
msg.data.req.clk = clk->clk_type;
ret = imx_scu_call_rpc(ccm_ipc_handle, &msg, true);
if (ret) {
pr_err("%s: failed to get clock rate %d\n",
clk_hw_get_name(hw), ret);
return 0;
}
return le32_to_cpu(msg.data.resp.rate);
}
/*
* clk_scu_round_rate - Round clock rate for a SCU clock
* @hw: clock to round rate for
* @rate: rate to round
* @parent_rate: parent rate provided by common clock framework, not used
*
* Returns the current clock rate, or zero in failure.
*/
static long clk_scu_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
/*
* Assume we support all the requested rate and let the SCU firmware
* to handle the left work
*/
return rate;
}
/*
* clk_scu_set_rate - Set rate for a SCU clock
* @hw: clock to change rate for
* @rate: target rate for the clock
* @parent_rate: rate of the clock parent, not used for SCU clocks
*
* Sets a clock frequency for a SCU clock. Returns the SCU
* protocol status.
*/
static int clk_scu_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_scu *clk = to_clk_scu(hw);
struct imx_sc_msg_req_set_clock_rate msg;
struct imx_sc_rpc_msg *hdr = &msg.hdr;
hdr->ver = IMX_SC_RPC_VERSION;
hdr->svc = IMX_SC_RPC_SVC_PM;
hdr->func = IMX_SC_PM_FUNC_SET_CLOCK_RATE;
hdr->size = 3;
msg.rate = cpu_to_le32(rate);
msg.resource = cpu_to_le16(clk->rsrc_id);
msg.clk = clk->clk_type;
return imx_scu_call_rpc(ccm_ipc_handle, &msg, true);
}
static int sc_pm_clock_enable(struct imx_sc_ipc *ipc, u16 resource,
u8 clk, bool enable, bool autog)
{
struct imx_sc_msg_req_clock_enable msg;
struct imx_sc_rpc_msg *hdr = &msg.hdr;
hdr->ver = IMX_SC_RPC_VERSION;
hdr->svc = IMX_SC_RPC_SVC_PM;
hdr->func = IMX_SC_PM_FUNC_CLOCK_ENABLE;
hdr->size = 3;
msg.resource = cpu_to_le16(resource);
msg.clk = clk;
msg.enable = enable;
msg.autog = autog;
return imx_scu_call_rpc(ccm_ipc_handle, &msg, true);
}
/*
* clk_scu_prepare - Enable a SCU clock
* @hw: clock to enable
*
* Enable the clock at the DSC slice level
*/
static int clk_scu_prepare(struct clk_hw *hw)
{
struct clk_scu *clk = to_clk_scu(hw);
return sc_pm_clock_enable(ccm_ipc_handle, clk->rsrc_id,
clk->clk_type, true, false);
}
/*
* clk_scu_unprepare - Disable a SCU clock
* @hw: clock to enable
*
* Disable the clock at the DSC slice level
*/
static void clk_scu_unprepare(struct clk_hw *hw)
{
struct clk_scu *clk = to_clk_scu(hw);
int ret;
ret = sc_pm_clock_enable(ccm_ipc_handle, clk->rsrc_id,
clk->clk_type, false, false);
if (ret)
pr_warn("%s: clk unprepare failed %d\n", clk_hw_get_name(hw),
ret);
}
static const struct clk_ops clk_scu_ops = {
.recalc_rate = clk_scu_recalc_rate,
.round_rate = clk_scu_round_rate,
.set_rate = clk_scu_set_rate,
.prepare = clk_scu_prepare,
.unprepare = clk_scu_unprepare,
};
struct clk_hw *imx_clk_scu(const char *name, u32 rsrc_id, u8 clk_type)
{
struct clk_init_data init;
struct clk_scu *clk;
struct clk_hw *hw;
int ret;
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
if (!clk)
return ERR_PTR(-ENOMEM);
clk->rsrc_id = rsrc_id;
clk->clk_type = clk_type;
init.name = name;
init.ops = &clk_scu_ops;
init.num_parents = 0;
/*
* Note on MX8, the clocks are tightly coupled with power domain
* that once the power domain is off, the clock status may be
* lost. So we make it NOCACHE to let user to retrieve the real
* clock status from HW instead of using the possible invalid
* cached rate.
*/
init.flags = CLK_GET_RATE_NOCACHE;
clk->hw.init = &init;
hw = &clk->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(clk);
hw = ERR_PTR(ret);
}
return hw;
}