linux/drivers/clk/imx/clk-pllv1.c
Randy Dunlap 71e7623161 clk: imx: pllv1: fix kernel-doc notation for struct clk_pllv1
Convert struct clk_pllv1 comments to kernel-doc notation and move them
below the MFN_* macros.

Fixes this kernel-doc warning:

drivers/clk/imx/clk-pllv1.c:12: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * pll v1

Fixes: 2af9e6db14 ("ARM i.MX: Add common clock support for pllv1")
Fixes: a594790368 ("ARM: imx: pllv1: Fix PLL calculation for i.MX27")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Abel Vesa <abel.vesa@nxp.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-imx@nxp.com
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20211115032607.28970-1-rdunlap@infradead.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-12-02 17:26:40 -08:00

146 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/bits.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include "clk.h"
#define MFN_BITS (10)
#define MFN_SIGN (BIT(MFN_BITS - 1))
#define MFN_MASK (MFN_SIGN - 1)
/**
* struct clk_pllv1 - IMX PLLv1 clock descriptor
*
* @hw: clock source
* @base: base address of pll registers
* @type: type of IMX_PLLV1
*
* PLL clock version 1, found on i.MX1/21/25/27/31/35
*/
struct clk_pllv1 {
struct clk_hw hw;
void __iomem *base;
enum imx_pllv1_type type;
};
#define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk))
static inline bool is_imx1_pllv1(struct clk_pllv1 *pll)
{
return pll->type == IMX_PLLV1_IMX1;
}
static inline bool is_imx21_pllv1(struct clk_pllv1 *pll)
{
return pll->type == IMX_PLLV1_IMX21;
}
static inline bool is_imx27_pllv1(struct clk_pllv1 *pll)
{
return pll->type == IMX_PLLV1_IMX27;
}
static inline bool mfn_is_negative(struct clk_pllv1 *pll, unsigned int mfn)
{
return !is_imx1_pllv1(pll) && !is_imx21_pllv1(pll) && (mfn & MFN_SIGN);
}
static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_pllv1 *pll = to_clk_pllv1(hw);
unsigned long long ull;
int mfn_abs;
unsigned int mfi, mfn, mfd, pd;
u32 reg;
unsigned long rate;
reg = readl(pll->base);
/*
* Get the resulting clock rate from a PLL register value and the input
* frequency. PLLs with this register layout can be found on i.MX1,
* i.MX21, i.MX27 and i,MX31
*
* mfi + mfn / (mfd + 1)
* f = 2 * f_ref * --------------------
* pd + 1
*/
mfi = (reg >> 10) & 0xf;
mfn = reg & 0x3ff;
mfd = (reg >> 16) & 0x3ff;
pd = (reg >> 26) & 0xf;
mfi = mfi <= 5 ? 5 : mfi;
mfn_abs = mfn;
/*
* On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit
* 2's complements number.
* On i.MX27 the bit 9 is the sign bit.
*/
if (mfn_is_negative(pll, mfn)) {
if (is_imx27_pllv1(pll))
mfn_abs = mfn & MFN_MASK;
else
mfn_abs = BIT(MFN_BITS) - mfn;
}
rate = parent_rate * 2;
rate /= pd + 1;
ull = (unsigned long long)rate * mfn_abs;
do_div(ull, mfd + 1);
if (mfn_is_negative(pll, mfn))
ull = (rate * mfi) - ull;
else
ull = (rate * mfi) + ull;
return ull;
}
static const struct clk_ops clk_pllv1_ops = {
.recalc_rate = clk_pllv1_recalc_rate,
};
struct clk_hw *imx_clk_hw_pllv1(enum imx_pllv1_type type, const char *name,
const char *parent, void __iomem *base)
{
struct clk_pllv1 *pll;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
pll = kmalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
pll->base = base;
pll->type = type;
init.name = name;
init.ops = &clk_pllv1_ops;
init.flags = 0;
init.parent_names = &parent;
init.num_parents = 1;
pll->hw.init = &init;
hw = &pll->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(pll);
return ERR_PTR(ret);
}
return hw;
}