linux/drivers/clk/qcom/clk-rcg.h
Amit Nischal 7ef6f11887 clk: qcom: Configure the RCGs to a safe source as needed
For some root clock generators, there could be child branches which are
controlled by an entity other than application processor subsystem. For
such RCGs, as per application processor subsystem clock driver, all of
its downstream clocks are disabled and RCG is in disabled state but in
reality downstream clocks can be left enabled before.

So in this scenario, when RCG is disabled as per clock driver's point of
view and when rate scaling request comes before downstream clock enable
request, then RCG fails to update its configuration because in reality
RCG is on and it expects its new source to already be in enable state but
in reality new source is off. In order to avoid having the RCG to go into
an invalid state, add support to update the CFG, M, N and D registers
during set_rate() without configuration update and defer the actual RCG
configuration update to be done during clk_enable() as at this point of
time, both its new parent and safe source will be already enabled and RCG
can safely switch to new parent.

During clk_disable() request, configure it to safe source as both its
parents, safe source and current parent will be enabled and RCG can
safely execute a switch.

Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Amit Nischal <anischal@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-05-08 11:22:55 -07:00

165 lines
3.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2013, 2018, The Linux Foundation. All rights reserved. */
#ifndef __QCOM_CLK_RCG_H__
#define __QCOM_CLK_RCG_H__
#include <linux/clk-provider.h>
#include "clk-regmap.h"
struct freq_tbl {
unsigned long freq;
u8 src;
u8 pre_div;
u16 m;
u16 n;
};
/**
* struct mn - M/N:D counter
* @mnctr_en_bit: bit to enable mn counter
* @mnctr_reset_bit: bit to assert mn counter reset
* @mnctr_mode_shift: lowest bit of mn counter mode field
* @n_val_shift: lowest bit of n value field
* @m_val_shift: lowest bit of m value field
* @width: number of bits in m/n/d values
* @reset_in_cc: true if the mnctr_reset_bit is in the CC register
*/
struct mn {
u8 mnctr_en_bit;
u8 mnctr_reset_bit;
u8 mnctr_mode_shift;
#define MNCTR_MODE_DUAL 0x2
#define MNCTR_MODE_MASK 0x3
u8 n_val_shift;
u8 m_val_shift;
u8 width;
bool reset_in_cc;
};
/**
* struct pre_div - pre-divider
* @pre_div_shift: lowest bit of pre divider field
* @pre_div_width: number of bits in predivider
*/
struct pre_div {
u8 pre_div_shift;
u8 pre_div_width;
};
/**
* struct src_sel - source selector
* @src_sel_shift: lowest bit of source selection field
* @parent_map: map from software's parent index to hardware's src_sel field
*/
struct src_sel {
u8 src_sel_shift;
#define SRC_SEL_MASK 0x7
const struct parent_map *parent_map;
};
/**
* struct clk_rcg - root clock generator
*
* @ns_reg: NS register
* @md_reg: MD register
* @mn: mn counter
* @p: pre divider
* @s: source selector
* @freq_tbl: frequency table
* @clkr: regmap clock handle
* @lock: register lock
*
*/
struct clk_rcg {
u32 ns_reg;
u32 md_reg;
struct mn mn;
struct pre_div p;
struct src_sel s;
const struct freq_tbl *freq_tbl;
struct clk_regmap clkr;
};
extern const struct clk_ops clk_rcg_ops;
extern const struct clk_ops clk_rcg_bypass_ops;
extern const struct clk_ops clk_rcg_bypass2_ops;
extern const struct clk_ops clk_rcg_pixel_ops;
extern const struct clk_ops clk_rcg_esc_ops;
extern const struct clk_ops clk_rcg_lcc_ops;
#define to_clk_rcg(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg, clkr)
/**
* struct clk_dyn_rcg - root clock generator with glitch free mux
*
* @mux_sel_bit: bit to switch glitch free mux
* @ns_reg: NS0 and NS1 register
* @md_reg: MD0 and MD1 register
* @bank_reg: register to XOR @mux_sel_bit into to switch glitch free mux
* @mn: mn counter (banked)
* @s: source selector (banked)
* @freq_tbl: frequency table
* @clkr: regmap clock handle
* @lock: register lock
*
*/
struct clk_dyn_rcg {
u32 ns_reg[2];
u32 md_reg[2];
u32 bank_reg;
u8 mux_sel_bit;
struct mn mn[2];
struct pre_div p[2];
struct src_sel s[2];
const struct freq_tbl *freq_tbl;
struct clk_regmap clkr;
};
extern const struct clk_ops clk_dyn_rcg_ops;
#define to_clk_dyn_rcg(_hw) \
container_of(to_clk_regmap(_hw), struct clk_dyn_rcg, clkr)
/**
* struct clk_rcg2 - root clock generator
*
* @cmd_rcgr: corresponds to *_CMD_RCGR
* @mnd_width: number of bits in m/n/d values
* @hid_width: number of bits in half integer divider
* @safe_src_index: safe src index value
* @parent_map: map from software's parent index to hardware's src_sel field
* @freq_tbl: frequency table
* @clkr: regmap clock handle
*
*/
struct clk_rcg2 {
u32 cmd_rcgr;
u8 mnd_width;
u8 hid_width;
u8 safe_src_index;
const struct parent_map *parent_map;
const struct freq_tbl *freq_tbl;
struct clk_regmap clkr;
};
#define to_clk_rcg2(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg2, clkr)
extern const struct clk_ops clk_rcg2_ops;
extern const struct clk_ops clk_rcg2_floor_ops;
extern const struct clk_ops clk_edp_pixel_ops;
extern const struct clk_ops clk_byte_ops;
extern const struct clk_ops clk_byte2_ops;
extern const struct clk_ops clk_pixel_ops;
extern const struct clk_ops clk_gfx3d_ops;
extern const struct clk_ops clk_rcg2_shared_ops;
#endif