linux/drivers/clk/imx/clk-gate-93.c
Peng Fan 0836c8604a clk: imx: add i.MX93 clk gate
i.MX93 LPCG is different from i.MX8M CCGR. Although imx_clk_hw_gate4_flags
is used here, it not strictly match i.MX93. i.MX93 has such design:
 - LPCG_DIRECT use BIT0 as on/off gate when LPCG_AUTHEN CPU_LPM is 0
 - LPCG_LPM_CUR use BIT[2:0] as on/off gate when LPCG_AUTHEN CPU_LPM is 1

The current implementation suppose CPU_LPM is 0, and use LPCG_DIRECT
BIT[1:0] as on/off gate. Although BIT1 is touched, actually BIT1 is
reserved.

And imx_clk_hw_gate4_flags use mask 0x3 to determine whether the clk
is enabled or not, but i.MX93 LPCG only use BIT0 to control when CPU_LPM
is 0. So clk disabled unused during kernel boot not able to gate off
the unused clocks.

To match i.MX93 LPCG, introduce imx93_clk_gate.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20220830033137.4149542-6-peng.fan@oss.nxp.com
2022-09-19 13:06:45 +03:00

200 lines
4.4 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2022 NXP
*
* Peng Fan <peng.fan@nxp.com>
*/
#include <linux/clk-provider.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/slab.h>
#include "clk.h"
#define DIRECT_OFFSET 0x0
/*
* 0b000 - LPCG will be OFF in any CPU mode.
* 0b100 - LPCG will be ON in any CPU mode.
*/
#define LPM_SETTING_OFF 0x0
#define LPM_SETTING_ON 0x4
#define LPM_CUR_OFFSET 0x1c
#define AUTHEN_OFFSET 0x30
#define CPULPM_EN BIT(2)
#define TZ_NS_SHIFT 9
#define TZ_NS_MASK BIT(9)
#define WHITE_LIST_SHIFT 16
struct imx93_clk_gate {
struct clk_hw hw;
void __iomem *reg;
u32 bit_idx;
u32 val;
u32 mask;
spinlock_t *lock;
unsigned int *share_count;
};
#define to_imx93_clk_gate(_hw) container_of(_hw, struct imx93_clk_gate, hw)
static void imx93_clk_gate_do_hardware(struct clk_hw *hw, bool enable)
{
struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
u32 val;
val = readl(gate->reg + AUTHEN_OFFSET);
if (val & CPULPM_EN) {
val = enable ? LPM_SETTING_ON : LPM_SETTING_OFF;
writel(val, gate->reg + LPM_CUR_OFFSET);
} else {
val = readl(gate->reg + DIRECT_OFFSET);
val &= ~(gate->mask << gate->bit_idx);
if (enable)
val |= (gate->val & gate->mask) << gate->bit_idx;
writel(val, gate->reg + DIRECT_OFFSET);
}
}
static int imx93_clk_gate_enable(struct clk_hw *hw)
{
struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
unsigned long flags;
spin_lock_irqsave(gate->lock, flags);
if (gate->share_count && (*gate->share_count)++ > 0)
goto out;
imx93_clk_gate_do_hardware(hw, true);
out:
spin_unlock_irqrestore(gate->lock, flags);
return 0;
}
static void imx93_clk_gate_disable(struct clk_hw *hw)
{
struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
unsigned long flags;
spin_lock_irqsave(gate->lock, flags);
if (gate->share_count) {
if (WARN_ON(*gate->share_count == 0))
goto out;
else if (--(*gate->share_count) > 0)
goto out;
}
imx93_clk_gate_do_hardware(hw, false);
out:
spin_unlock_irqrestore(gate->lock, flags);
}
static int imx93_clk_gate_reg_is_enabled(struct imx93_clk_gate *gate)
{
u32 val = readl(gate->reg + AUTHEN_OFFSET);
if (val & CPULPM_EN) {
val = readl(gate->reg + LPM_CUR_OFFSET);
if (val == LPM_SETTING_ON)
return 1;
} else {
val = readl(gate->reg);
if (((val >> gate->bit_idx) & gate->mask) == gate->val)
return 1;
}
return 0;
}
static int imx93_clk_gate_is_enabled(struct clk_hw *hw)
{
struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
unsigned long flags;
int ret;
spin_lock_irqsave(gate->lock, flags);
ret = imx93_clk_gate_reg_is_enabled(gate);
spin_unlock_irqrestore(gate->lock, flags);
return ret;
}
static void imx93_clk_gate_disable_unused(struct clk_hw *hw)
{
struct imx93_clk_gate *gate = to_imx93_clk_gate(hw);
unsigned long flags;
spin_lock_irqsave(gate->lock, flags);
if (!gate->share_count || *gate->share_count == 0)
imx93_clk_gate_do_hardware(hw, false);
spin_unlock_irqrestore(gate->lock, flags);
}
static const struct clk_ops imx93_clk_gate_ops = {
.enable = imx93_clk_gate_enable,
.disable = imx93_clk_gate_disable,
.disable_unused = imx93_clk_gate_disable_unused,
.is_enabled = imx93_clk_gate_is_enabled,
};
static const struct clk_ops imx93_clk_gate_ro_ops = {
.is_enabled = imx93_clk_gate_is_enabled,
};
struct clk_hw *imx93_clk_gate(struct device *dev, const char *name, const char *parent_name,
unsigned long flags, void __iomem *reg, u32 bit_idx, u32 val,
u32 mask, u32 domain_id, unsigned int *share_count)
{
struct imx93_clk_gate *gate;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
u32 authen;
gate = kzalloc(sizeof(struct imx93_clk_gate), GFP_KERNEL);
if (!gate)
return ERR_PTR(-ENOMEM);
gate->reg = reg;
gate->lock = &imx_ccm_lock;
gate->bit_idx = bit_idx;
gate->val = val;
gate->mask = mask;
gate->share_count = share_count;
init.name = name;
init.ops = &imx93_clk_gate_ops;
init.flags = flags | CLK_SET_RATE_PARENT | CLK_OPS_PARENT_ENABLE;
init.parent_names = parent_name ? &parent_name : NULL;
init.num_parents = parent_name ? 1 : 0;
gate->hw.init = &init;
hw = &gate->hw;
authen = readl(reg + AUTHEN_OFFSET);
if (!(authen & TZ_NS_MASK) || !(authen & BIT(WHITE_LIST_SHIFT + domain_id)))
init.ops = &imx93_clk_gate_ro_ops;
ret = clk_hw_register(dev, hw);
if (ret) {
kfree(gate);
return ERR_PTR(ret);
}
return hw;
}
EXPORT_SYMBOL_GPL(imx93_clk_gate);