linux/drivers/clk/bcm/clk-iproc-pll.c
Ray Jui 5fe225c105 clk: iproc: add initial common clock support
This adds basic and generic support for various iProc PLLs and clocks
including the ARMPLL, GENPLL, LCPLL, MIPIPLL, and ASIU clocks.

SoCs under the iProc architecture can define their specific register
offsets and clock parameters for their PLL and clock controllers. These
parameters can be passed as arugments into the generic iProc PLL and
clock setup functions

Derived from code originally provided by Jonathan Richardson
<jonathar@broadcom.com>

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-06-18 12:36:38 -07:00

717 lines
18 KiB
C

/*
* Copyright (C) 2014 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/clkdev.h>
#include <linux/of_address.h>
#include <linux/delay.h>
#include "clk-iproc.h"
#define PLL_VCO_HIGH_SHIFT 19
#define PLL_VCO_LOW_SHIFT 30
/* number of delay loops waiting for PLL to lock */
#define LOCK_DELAY 100
/* number of VCO frequency bands */
#define NUM_FREQ_BANDS 8
#define NUM_KP_BANDS 3
enum kp_band {
KP_BAND_MID = 0,
KP_BAND_HIGH,
KP_BAND_HIGH_HIGH
};
static const unsigned int kp_table[NUM_KP_BANDS][NUM_FREQ_BANDS] = {
{ 5, 6, 6, 7, 7, 8, 9, 10 },
{ 4, 4, 5, 5, 6, 7, 8, 9 },
{ 4, 5, 5, 6, 7, 8, 9, 10 },
};
static const unsigned long ref_freq_table[NUM_FREQ_BANDS][2] = {
{ 10000000, 12500000 },
{ 12500000, 15000000 },
{ 15000000, 20000000 },
{ 20000000, 25000000 },
{ 25000000, 50000000 },
{ 50000000, 75000000 },
{ 75000000, 100000000 },
{ 100000000, 125000000 },
};
enum vco_freq_range {
VCO_LOW = 700000000U,
VCO_MID = 1200000000U,
VCO_HIGH = 2200000000U,
VCO_HIGH_HIGH = 3100000000U,
VCO_MAX = 4000000000U,
};
struct iproc_pll;
struct iproc_clk {
struct clk_hw hw;
const char *name;
struct iproc_pll *pll;
unsigned long rate;
const struct iproc_clk_ctrl *ctrl;
};
struct iproc_pll {
void __iomem *pll_base;
void __iomem *pwr_base;
void __iomem *asiu_base;
const struct iproc_pll_ctrl *ctrl;
const struct iproc_pll_vco_param *vco_param;
unsigned int num_vco_entries;
struct clk_onecell_data clk_data;
struct iproc_clk *clks;
};
#define to_iproc_clk(hw) container_of(hw, struct iproc_clk, hw)
/*
* Based on the target frequency, find a match from the VCO frequency parameter
* table and return its index
*/
static int pll_get_rate_index(struct iproc_pll *pll, unsigned int target_rate)
{
int i;
for (i = 0; i < pll->num_vco_entries; i++)
if (target_rate == pll->vco_param[i].rate)
break;
if (i >= pll->num_vco_entries)
return -EINVAL;
return i;
}
static int get_kp(unsigned long ref_freq, enum kp_band kp_index)
{
int i;
if (ref_freq < ref_freq_table[0][0])
return -EINVAL;
for (i = 0; i < NUM_FREQ_BANDS; i++) {
if (ref_freq >= ref_freq_table[i][0] &&
ref_freq < ref_freq_table[i][1])
return kp_table[kp_index][i];
}
return -EINVAL;
}
static int pll_wait_for_lock(struct iproc_pll *pll)
{
int i;
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
for (i = 0; i < LOCK_DELAY; i++) {
u32 val = readl(pll->pll_base + ctrl->status.offset);
if (val & (1 << ctrl->status.shift))
return 0;
udelay(10);
}
return -EIO;
}
static void __pll_disable(struct iproc_pll *pll)
{
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
u32 val;
if (ctrl->flags & IPROC_CLK_PLL_ASIU) {
val = readl(pll->asiu_base + ctrl->asiu.offset);
val &= ~(1 << ctrl->asiu.en_shift);
writel(val, pll->asiu_base + ctrl->asiu.offset);
}
/* latch input value so core power can be shut down */
val = readl(pll->pwr_base + ctrl->aon.offset);
val |= (1 << ctrl->aon.iso_shift);
writel(val, pll->pwr_base + ctrl->aon.offset);
/* power down the core */
val &= ~(bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift);
writel(val, pll->pwr_base + ctrl->aon.offset);
}
static int __pll_enable(struct iproc_pll *pll)
{
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
u32 val;
/* power up the PLL and make sure it's not latched */
val = readl(pll->pwr_base + ctrl->aon.offset);
val |= bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift;
val &= ~(1 << ctrl->aon.iso_shift);
writel(val, pll->pwr_base + ctrl->aon.offset);
/* certain PLLs also need to be ungated from the ASIU top level */
if (ctrl->flags & IPROC_CLK_PLL_ASIU) {
val = readl(pll->asiu_base + ctrl->asiu.offset);
val |= (1 << ctrl->asiu.en_shift);
writel(val, pll->asiu_base + ctrl->asiu.offset);
}
return 0;
}
static void __pll_put_in_reset(struct iproc_pll *pll)
{
u32 val;
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
const struct iproc_pll_reset_ctrl *reset = &ctrl->reset;
val = readl(pll->pll_base + reset->offset);
val &= ~(1 << reset->reset_shift | 1 << reset->p_reset_shift);
writel(val, pll->pll_base + reset->offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + reset->offset);
}
static void __pll_bring_out_reset(struct iproc_pll *pll, unsigned int kp,
unsigned int ka, unsigned int ki)
{
u32 val;
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
const struct iproc_pll_reset_ctrl *reset = &ctrl->reset;
val = readl(pll->pll_base + reset->offset);
val &= ~(bit_mask(reset->ki_width) << reset->ki_shift |
bit_mask(reset->kp_width) << reset->kp_shift |
bit_mask(reset->ka_width) << reset->ka_shift);
val |= ki << reset->ki_shift | kp << reset->kp_shift |
ka << reset->ka_shift;
val |= 1 << reset->reset_shift | 1 << reset->p_reset_shift;
writel(val, pll->pll_base + reset->offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + reset->offset);
}
static int pll_set_rate(struct iproc_clk *clk, unsigned int rate_index,
unsigned long parent_rate)
{
struct iproc_pll *pll = clk->pll;
const struct iproc_pll_vco_param *vco = &pll->vco_param[rate_index];
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
int ka = 0, ki, kp, ret;
unsigned long rate = vco->rate;
u32 val;
enum kp_band kp_index;
unsigned long ref_freq;
/*
* reference frequency = parent frequency / PDIV
* If PDIV = 0, then it becomes a multiplier (x2)
*/
if (vco->pdiv == 0)
ref_freq = parent_rate * 2;
else
ref_freq = parent_rate / vco->pdiv;
/* determine Ki and Kp index based on target VCO frequency */
if (rate >= VCO_LOW && rate < VCO_HIGH) {
ki = 4;
kp_index = KP_BAND_MID;
} else if (rate >= VCO_HIGH && rate && rate < VCO_HIGH_HIGH) {
ki = 3;
kp_index = KP_BAND_HIGH;
} else if (rate >= VCO_HIGH_HIGH && rate < VCO_MAX) {
ki = 3;
kp_index = KP_BAND_HIGH_HIGH;
} else {
pr_err("%s: pll: %s has invalid rate: %lu\n", __func__,
clk->name, rate);
return -EINVAL;
}
kp = get_kp(ref_freq, kp_index);
if (kp < 0) {
pr_err("%s: pll: %s has invalid kp\n", __func__, clk->name);
return kp;
}
ret = __pll_enable(pll);
if (ret) {
pr_err("%s: pll: %s fails to enable\n", __func__, clk->name);
return ret;
}
/* put PLL in reset */
__pll_put_in_reset(pll);
writel(0, pll->pll_base + ctrl->vco_ctrl.u_offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->vco_ctrl.u_offset);
val = readl(pll->pll_base + ctrl->vco_ctrl.l_offset);
if (rate >= VCO_LOW && rate < VCO_MID)
val |= (1 << PLL_VCO_LOW_SHIFT);
if (rate < VCO_HIGH)
val &= ~(1 << PLL_VCO_HIGH_SHIFT);
else
val |= (1 << PLL_VCO_HIGH_SHIFT);
writel(val, pll->pll_base + ctrl->vco_ctrl.l_offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->vco_ctrl.l_offset);
/* program integer part of NDIV */
val = readl(pll->pll_base + ctrl->ndiv_int.offset);
val &= ~(bit_mask(ctrl->ndiv_int.width) << ctrl->ndiv_int.shift);
val |= vco->ndiv_int << ctrl->ndiv_int.shift;
writel(val, pll->pll_base + ctrl->ndiv_int.offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->ndiv_int.offset);
/* program fractional part of NDIV */
if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) {
val = readl(pll->pll_base + ctrl->ndiv_frac.offset);
val &= ~(bit_mask(ctrl->ndiv_frac.width) <<
ctrl->ndiv_frac.shift);
val |= vco->ndiv_frac << ctrl->ndiv_frac.shift;
writel(val, pll->pll_base + ctrl->ndiv_frac.offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->ndiv_frac.offset);
}
/* program PDIV */
val = readl(pll->pll_base + ctrl->pdiv.offset);
val &= ~(bit_mask(ctrl->pdiv.width) << ctrl->pdiv.shift);
val |= vco->pdiv << ctrl->pdiv.shift;
writel(val, pll->pll_base + ctrl->pdiv.offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->pdiv.offset);
__pll_bring_out_reset(pll, kp, ka, ki);
ret = pll_wait_for_lock(pll);
if (ret < 0) {
pr_err("%s: pll: %s failed to lock\n", __func__, clk->name);
return ret;
}
return 0;
}
static int iproc_pll_enable(struct clk_hw *hw)
{
struct iproc_clk *clk = to_iproc_clk(hw);
struct iproc_pll *pll = clk->pll;
return __pll_enable(pll);
}
static void iproc_pll_disable(struct clk_hw *hw)
{
struct iproc_clk *clk = to_iproc_clk(hw);
struct iproc_pll *pll = clk->pll;
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
if (ctrl->flags & IPROC_CLK_AON)
return;
__pll_disable(pll);
}
static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct iproc_clk *clk = to_iproc_clk(hw);
struct iproc_pll *pll = clk->pll;
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
u32 val;
u64 ndiv;
unsigned int ndiv_int, ndiv_frac, pdiv;
if (parent_rate == 0)
return 0;
/* PLL needs to be locked */
val = readl(pll->pll_base + ctrl->status.offset);
if ((val & (1 << ctrl->status.shift)) == 0) {
clk->rate = 0;
return 0;
}
/*
* PLL output frequency =
*
* ((ndiv_int + ndiv_frac / 2^20) * (parent clock rate / pdiv)
*/
val = readl(pll->pll_base + ctrl->ndiv_int.offset);
ndiv_int = (val >> ctrl->ndiv_int.shift) &
bit_mask(ctrl->ndiv_int.width);
ndiv = ndiv_int << ctrl->ndiv_int.shift;
if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) {
val = readl(pll->pll_base + ctrl->ndiv_frac.offset);
ndiv_frac = (val >> ctrl->ndiv_frac.shift) &
bit_mask(ctrl->ndiv_frac.width);
if (ndiv_frac != 0)
ndiv = (ndiv_int << ctrl->ndiv_int.shift) | ndiv_frac;
}
val = readl(pll->pll_base + ctrl->pdiv.offset);
pdiv = (val >> ctrl->pdiv.shift) & bit_mask(ctrl->pdiv.width);
clk->rate = (ndiv * parent_rate) >> ctrl->ndiv_int.shift;
if (pdiv == 0)
clk->rate *= 2;
else
clk->rate /= pdiv;
return clk->rate;
}
static long iproc_pll_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
unsigned i;
struct iproc_clk *clk = to_iproc_clk(hw);
struct iproc_pll *pll = clk->pll;
if (rate == 0 || *parent_rate == 0 || !pll->vco_param)
return -EINVAL;
for (i = 0; i < pll->num_vco_entries; i++) {
if (rate <= pll->vco_param[i].rate)
break;
}
if (i == pll->num_vco_entries)
i--;
return pll->vco_param[i].rate;
}
static int iproc_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct iproc_clk *clk = to_iproc_clk(hw);
struct iproc_pll *pll = clk->pll;
int rate_index, ret;
rate_index = pll_get_rate_index(pll, rate);
if (rate_index < 0)
return rate_index;
ret = pll_set_rate(clk, rate_index, parent_rate);
return ret;
}
static const struct clk_ops iproc_pll_ops = {
.enable = iproc_pll_enable,
.disable = iproc_pll_disable,
.recalc_rate = iproc_pll_recalc_rate,
.round_rate = iproc_pll_round_rate,
.set_rate = iproc_pll_set_rate,
};
static int iproc_clk_enable(struct clk_hw *hw)
{
struct iproc_clk *clk = to_iproc_clk(hw);
const struct iproc_clk_ctrl *ctrl = clk->ctrl;
struct iproc_pll *pll = clk->pll;
u32 val;
/* channel enable is active low */
val = readl(pll->pll_base + ctrl->enable.offset);
val &= ~(1 << ctrl->enable.enable_shift);
writel(val, pll->pll_base + ctrl->enable.offset);
/* also make sure channel is not held */
val = readl(pll->pll_base + ctrl->enable.offset);
val &= ~(1 << ctrl->enable.hold_shift);
writel(val, pll->pll_base + ctrl->enable.offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->enable.offset);
return 0;
}
static void iproc_clk_disable(struct clk_hw *hw)
{
struct iproc_clk *clk = to_iproc_clk(hw);
const struct iproc_clk_ctrl *ctrl = clk->ctrl;
struct iproc_pll *pll = clk->pll;
u32 val;
if (ctrl->flags & IPROC_CLK_AON)
return;
val = readl(pll->pll_base + ctrl->enable.offset);
val |= 1 << ctrl->enable.enable_shift;
writel(val, pll->pll_base + ctrl->enable.offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->enable.offset);
}
static unsigned long iproc_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct iproc_clk *clk = to_iproc_clk(hw);
const struct iproc_clk_ctrl *ctrl = clk->ctrl;
struct iproc_pll *pll = clk->pll;
u32 val;
unsigned int mdiv;
if (parent_rate == 0)
return 0;
val = readl(pll->pll_base + ctrl->mdiv.offset);
mdiv = (val >> ctrl->mdiv.shift) & bit_mask(ctrl->mdiv.width);
if (mdiv == 0)
mdiv = 256;
clk->rate = parent_rate / mdiv;
return clk->rate;
}
static long iproc_clk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
unsigned int div;
if (rate == 0 || *parent_rate == 0)
return -EINVAL;
if (rate == *parent_rate)
return *parent_rate;
div = DIV_ROUND_UP(*parent_rate, rate);
if (div < 2)
return *parent_rate;
if (div > 256)
div = 256;
return *parent_rate / div;
}
static int iproc_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct iproc_clk *clk = to_iproc_clk(hw);
const struct iproc_clk_ctrl *ctrl = clk->ctrl;
struct iproc_pll *pll = clk->pll;
u32 val;
unsigned int div;
if (rate == 0 || parent_rate == 0)
return -EINVAL;
div = DIV_ROUND_UP(parent_rate, rate);
if (div > 256)
return -EINVAL;
val = readl(pll->pll_base + ctrl->mdiv.offset);
if (div == 256) {
val &= ~(bit_mask(ctrl->mdiv.width) << ctrl->mdiv.shift);
} else {
val &= ~(bit_mask(ctrl->mdiv.width) << ctrl->mdiv.shift);
val |= div << ctrl->mdiv.shift;
}
writel(val, pll->pll_base + ctrl->mdiv.offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->mdiv.offset);
clk->rate = parent_rate / div;
return 0;
}
static const struct clk_ops iproc_clk_ops = {
.enable = iproc_clk_enable,
.disable = iproc_clk_disable,
.recalc_rate = iproc_clk_recalc_rate,
.round_rate = iproc_clk_round_rate,
.set_rate = iproc_clk_set_rate,
};
/**
* Some PLLs require the PLL SW override bit to be set before changes can be
* applied to the PLL
*/
static void iproc_pll_sw_cfg(struct iproc_pll *pll)
{
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
if (ctrl->flags & IPROC_CLK_PLL_NEEDS_SW_CFG) {
u32 val;
val = readl(pll->pll_base + ctrl->sw_ctrl.offset);
val |= BIT(ctrl->sw_ctrl.shift);
writel(val, pll->pll_base + ctrl->sw_ctrl.offset);
if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK))
readl(pll->pll_base + ctrl->sw_ctrl.offset);
}
}
void __init iproc_pll_clk_setup(struct device_node *node,
const struct iproc_pll_ctrl *pll_ctrl,
const struct iproc_pll_vco_param *vco,
unsigned int num_vco_entries,
const struct iproc_clk_ctrl *clk_ctrl,
unsigned int num_clks)
{
int i, ret;
struct clk *clk;
struct iproc_pll *pll;
struct iproc_clk *iclk;
struct clk_init_data init;
const char *parent_name;
if (WARN_ON(!pll_ctrl) || WARN_ON(!clk_ctrl))
return;
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (WARN_ON(!pll))
return;
pll->clk_data.clk_num = num_clks;
pll->clk_data.clks = kcalloc(num_clks, sizeof(*pll->clk_data.clks),
GFP_KERNEL);
if (WARN_ON(!pll->clk_data.clks))
goto err_clk_data;
pll->clks = kcalloc(num_clks, sizeof(*pll->clks), GFP_KERNEL);
if (WARN_ON(!pll->clks))
goto err_clks;
pll->pll_base = of_iomap(node, 0);
if (WARN_ON(!pll->pll_base))
goto err_pll_iomap;
pll->pwr_base = of_iomap(node, 1);
if (WARN_ON(!pll->pwr_base))
goto err_pwr_iomap;
/* some PLLs require gating control at the top ASIU level */
if (pll_ctrl->flags & IPROC_CLK_PLL_ASIU) {
pll->asiu_base = of_iomap(node, 2);
if (WARN_ON(!pll->asiu_base))
goto err_asiu_iomap;
}
/* initialize and register the PLL itself */
pll->ctrl = pll_ctrl;
iclk = &pll->clks[0];
iclk->pll = pll;
iclk->name = node->name;
init.name = node->name;
init.ops = &iproc_pll_ops;
init.flags = 0;
parent_name = of_clk_get_parent_name(node, 0);
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
iclk->hw.init = &init;
if (vco) {
pll->num_vco_entries = num_vco_entries;
pll->vco_param = vco;
}
iproc_pll_sw_cfg(pll);
clk = clk_register(NULL, &iclk->hw);
if (WARN_ON(IS_ERR(clk)))
goto err_pll_register;
pll->clk_data.clks[0] = clk;
/* now initialize and register all leaf clocks */
for (i = 1; i < num_clks; i++) {
const char *clk_name;
memset(&init, 0, sizeof(init));
parent_name = node->name;
clk_name = kzalloc(IPROC_CLK_NAME_LEN, GFP_KERNEL);
if (WARN_ON(!clk_name))
goto err_clk_register;
ret = of_property_read_string_index(node, "clock-output-names",
i, &clk_name);
if (WARN_ON(ret))
goto err_clk_register;
iclk = &pll->clks[i];
iclk->name = clk_name;
iclk->pll = pll;
iclk->ctrl = &clk_ctrl[i];
init.name = clk_name;
init.ops = &iproc_clk_ops;
init.flags = 0;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
iclk->hw.init = &init;
clk = clk_register(NULL, &iclk->hw);
if (WARN_ON(IS_ERR(clk)))
goto err_clk_register;
pll->clk_data.clks[i] = clk;
}
ret = of_clk_add_provider(node, of_clk_src_onecell_get, &pll->clk_data);
if (WARN_ON(ret))
goto err_clk_register;
return;
err_clk_register:
for (i = 0; i < num_clks; i++) {
kfree(pll->clks[i].name);
clk_unregister(pll->clk_data.clks[i]);
}
err_pll_register:
if (pll->asiu_base)
iounmap(pll->asiu_base);
err_asiu_iomap:
iounmap(pll->pwr_base);
err_pwr_iomap:
iounmap(pll->pll_base);
err_pll_iomap:
kfree(pll->clks);
err_clks:
kfree(pll->clk_data.clks);
err_clk_data:
kfree(pll);
}