linux/drivers/clk/imx/clk-sccg-pll.c
Lucas Stach ff70fbd0e8 clk: imx: Add SCCG PLL type
The SCCG is a new PLL type introduced on i.MX8.

The description of this SCCG clock can be found here:

https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-12-03 10:13:35 -08:00

257 lines
5.3 KiB
C

// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* Copyright 2018 NXP.
*
* This driver supports the SCCG plls found in the imx8m SOCs
*
* Documentation for this SCCG pll can be found at:
* https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834
*/
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/iopoll.h>
#include <linux/slab.h>
#include <linux/bitfield.h>
#include "clk.h"
/* PLL CFGs */
#define PLL_CFG0 0x0
#define PLL_CFG1 0x4
#define PLL_CFG2 0x8
#define PLL_DIVF1_MASK GENMASK(18, 13)
#define PLL_DIVF2_MASK GENMASK(12, 7)
#define PLL_DIVR1_MASK GENMASK(27, 25)
#define PLL_DIVR2_MASK GENMASK(24, 19)
#define PLL_REF_MASK GENMASK(2, 0)
#define PLL_LOCK_MASK BIT(31)
#define PLL_PD_MASK BIT(7)
#define OSC_25M 25000000
#define OSC_27M 27000000
#define PLL_SCCG_LOCK_TIMEOUT 70
struct clk_sccg_pll {
struct clk_hw hw;
void __iomem *base;
};
#define to_clk_sccg_pll(_hw) container_of(_hw, struct clk_sccg_pll, hw)
static int clk_pll_wait_lock(struct clk_sccg_pll *pll)
{
u32 val;
return readl_poll_timeout(pll->base, val, val & PLL_LOCK_MASK, 0,
PLL_SCCG_LOCK_TIMEOUT);
}
static int clk_pll1_is_prepared(struct clk_hw *hw)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
val = readl_relaxed(pll->base + PLL_CFG0);
return (val & PLL_PD_MASK) ? 0 : 1;
}
static unsigned long clk_pll1_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val, divf;
val = readl_relaxed(pll->base + PLL_CFG2);
divf = FIELD_GET(PLL_DIVF1_MASK, val);
return parent_rate * 2 * (divf + 1);
}
static long clk_pll1_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
unsigned long parent_rate = *prate;
u32 div;
if (!parent_rate)
return 0;
div = rate / (parent_rate * 2);
return parent_rate * div * 2;
}
static int clk_pll1_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
u32 divf;
if (!parent_rate)
return -EINVAL;
divf = rate / (parent_rate * 2);
val = readl_relaxed(pll->base + PLL_CFG2);
val &= ~PLL_DIVF1_MASK;
val |= FIELD_PREP(PLL_DIVF1_MASK, divf - 1);
writel_relaxed(val, pll->base + PLL_CFG2);
return clk_pll_wait_lock(pll);
}
static int clk_pll1_prepare(struct clk_hw *hw)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
val = readl_relaxed(pll->base + PLL_CFG0);
val &= ~PLL_PD_MASK;
writel_relaxed(val, pll->base + PLL_CFG0);
return clk_pll_wait_lock(pll);
}
static void clk_pll1_unprepare(struct clk_hw *hw)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val;
val = readl_relaxed(pll->base + PLL_CFG0);
val |= PLL_PD_MASK;
writel_relaxed(val, pll->base + PLL_CFG0);
}
static unsigned long clk_pll2_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
u32 val, ref, divr1, divf1, divr2, divf2;
u64 temp64;
val = readl_relaxed(pll->base + PLL_CFG0);
switch (FIELD_GET(PLL_REF_MASK, val)) {
case 0:
ref = OSC_25M;
break;
case 1:
ref = OSC_27M;
break;
default:
ref = OSC_25M;
break;
}
val = readl_relaxed(pll->base + PLL_CFG2);
divr1 = FIELD_GET(PLL_DIVR1_MASK, val);
divr2 = FIELD_GET(PLL_DIVR2_MASK, val);
divf1 = FIELD_GET(PLL_DIVF1_MASK, val);
divf2 = FIELD_GET(PLL_DIVF2_MASK, val);
temp64 = ref * 2;
temp64 *= (divf1 + 1) * (divf2 + 1);
do_div(temp64, (divr1 + 1) * (divr2 + 1));
return temp64;
}
static long clk_pll2_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
u32 div;
unsigned long parent_rate = *prate;
if (!parent_rate)
return 0;
div = rate / parent_rate;
return parent_rate * div;
}
static int clk_pll2_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
u32 val;
u32 divf;
struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
if (!parent_rate)
return -EINVAL;
divf = rate / parent_rate;
val = readl_relaxed(pll->base + PLL_CFG2);
val &= ~PLL_DIVF2_MASK;
val |= FIELD_PREP(PLL_DIVF2_MASK, divf - 1);
writel_relaxed(val, pll->base + PLL_CFG2);
return clk_pll_wait_lock(pll);
}
static const struct clk_ops clk_sccg_pll1_ops = {
.is_prepared = clk_pll1_is_prepared,
.recalc_rate = clk_pll1_recalc_rate,
.round_rate = clk_pll1_round_rate,
.set_rate = clk_pll1_set_rate,
};
static const struct clk_ops clk_sccg_pll2_ops = {
.prepare = clk_pll1_prepare,
.unprepare = clk_pll1_unprepare,
.recalc_rate = clk_pll2_recalc_rate,
.round_rate = clk_pll2_round_rate,
.set_rate = clk_pll2_set_rate,
};
struct clk *imx_clk_sccg_pll(const char *name,
const char *parent_name,
void __iomem *base,
enum imx_sccg_pll_type pll_type)
{
struct clk_sccg_pll *pll;
struct clk_init_data init;
struct clk_hw *hw;
int ret;
switch (pll_type) {
case SCCG_PLL1:
init.ops = &clk_sccg_pll1_ops;
break;
case SCCG_PLL2:
init.ops = &clk_sccg_pll2_ops;
break;
default:
return ERR_PTR(-EINVAL);
}
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
init.name = name;
init.flags = 0;
init.parent_names = &parent_name;
init.num_parents = 1;
pll->base = base;
pll->hw.init = &init;
hw = &pll->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(pll);
return ERR_PTR(ret);
}
return hw->clk;
}