clk: pxa: transfer CPU clock setting from pxa2xx-cpufreq

This is the initial stage to transfer the pxa25x and pxa27x CPU clocks
handling from cpufreq to the clock API. More precisely, the clocks
transferred are :
 - cpll : core pll, known also as the CPU core turbo frequency
 - core : core, known also as the CPU actual frequency, being either the
          CPU core turbo frequency or the CPU core run frequency

This transfer is a prequel to shrink the code in pxa2xx-cpufreq.c, so
that it can become, at least in devicetree builds, the casual cpufreq-dt
driver.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This commit is contained in:
Robert Jarzmik 2016-11-02 22:33:06 +01:00 committed by Stephen Boyd
parent 3bd31cdc4a
commit 9fe6942950
4 changed files with 415 additions and 28 deletions

View File

@ -18,6 +18,26 @@
#include <dt-bindings/clock/pxa-clock.h>
#include "clk-pxa.h"
#define KHz 1000
#define MHz (1000 * 1000)
#define MDREFR_K0DB4 (1 << 29) /* SDCLK0 Divide by 4 Control/Status */
#define MDREFR_K2FREE (1 << 25) /* SDRAM Free-Running Control */
#define MDREFR_K1FREE (1 << 24) /* SDRAM Free-Running Control */
#define MDREFR_K0FREE (1 << 23) /* SDRAM Free-Running Control */
#define MDREFR_SLFRSH (1 << 22) /* SDRAM Self-Refresh Control/Status */
#define MDREFR_APD (1 << 20) /* SDRAM/SSRAM Auto-Power-Down Enable */
#define MDREFR_K2DB2 (1 << 19) /* SDCLK2 Divide by 2 Control/Status */
#define MDREFR_K2RUN (1 << 18) /* SDCLK2 Run Control/Status */
#define MDREFR_K1DB2 (1 << 17) /* SDCLK1 Divide by 2 Control/Status */
#define MDREFR_K1RUN (1 << 16) /* SDCLK1 Run Control/Status */
#define MDREFR_E1PIN (1 << 15) /* SDCKE1 Level Control/Status */
#define MDREFR_K0DB2 (1 << 14) /* SDCLK0 Divide by 2 Control/Status */
#define MDREFR_K0RUN (1 << 13) /* SDCLK0 Run Control/Status */
#define MDREFR_E0PIN (1 << 12) /* SDCKE0 Level Control/Status */
#define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2)
#define MDREFR_DRI_MASK 0xFFF
DEFINE_SPINLOCK(lock);
static struct clk *pxa_clocks[CLK_MAX];
@ -106,3 +126,122 @@ void __init clk_pxa_dt_common_init(struct device_node *np)
{
of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data);
}
void pxa2xx_core_turbo_switch(bool on)
{
unsigned long flags;
unsigned int unused, clkcfg;
local_irq_save(flags);
asm("mrc p14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
clkcfg &= ~CLKCFG_TURBO & ~CLKCFG_HALFTURBO;
if (on)
clkcfg |= CLKCFG_TURBO;
clkcfg |= CLKCFG_FCS;
asm volatile(
" b 2f\n"
" .align 5\n"
"1: mcr p14, 0, %1, c6, c0, 0\n"
" b 3f\n"
"2: b 1b\n"
"3: nop\n"
: "=&r" (unused)
: "r" (clkcfg)
: );
local_irq_restore(flags);
}
void pxa2xx_cpll_change(struct pxa2xx_freq *freq,
u32 (*mdrefr_dri)(unsigned int), u32 *mdrefr, u32 *cccr)
{
unsigned int clkcfg = freq->clkcfg;
unsigned int unused, preset_mdrefr, postset_mdrefr;
unsigned long flags;
local_irq_save(flags);
/* Calculate the next MDREFR. If we're slowing down the SDRAM clock
* we need to preset the smaller DRI before the change. If we're
* speeding up we need to set the larger DRI value after the change.
*/
preset_mdrefr = postset_mdrefr = readl(mdrefr);
if ((preset_mdrefr & MDREFR_DRI_MASK) > mdrefr_dri(freq->membus_khz)) {
preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK);
preset_mdrefr |= mdrefr_dri(freq->membus_khz);
}
postset_mdrefr =
(postset_mdrefr & ~MDREFR_DRI_MASK) |
mdrefr_dri(freq->membus_khz);
/* If we're dividing the memory clock by two for the SDRAM clock, this
* must be set prior to the change. Clearing the divide must be done
* after the change.
*/
if (freq->div2) {
preset_mdrefr |= MDREFR_DB2_MASK;
postset_mdrefr |= MDREFR_DB2_MASK;
} else {
postset_mdrefr &= ~MDREFR_DB2_MASK;
}
/* Set new the CCCR and prepare CLKCFG */
writel(freq->cccr, cccr);
asm volatile(
" ldr r4, [%1]\n"
" b 2f\n"
" .align 5\n"
"1: str %3, [%1] /* preset the MDREFR */\n"
" mcr p14, 0, %2, c6, c0, 0 /* set CLKCFG[FCS] */\n"
" str %4, [%1] /* postset the MDREFR */\n"
" b 3f\n"
"2: b 1b\n"
"3: nop\n"
: "=&r" (unused)
: "r" (mdrefr), "r" (clkcfg), "r" (preset_mdrefr),
"r" (postset_mdrefr)
: "r4", "r5");
local_irq_restore(flags);
}
int pxa2xx_determine_rate(struct clk_rate_request *req,
struct pxa2xx_freq *freqs, int nb_freqs)
{
int i, closest_below = -1, closest_above = -1, ret = 0;
unsigned long rate;
for (i = 0; i < nb_freqs; i++) {
rate = freqs[i].cpll;
if (rate == req->rate)
break;
if (rate < req->min_rate)
continue;
if (rate > req->max_rate)
continue;
if (rate <= req->rate)
closest_below = i;
if ((rate >= req->rate) && (closest_above == -1))
closest_above = i;
}
req->best_parent_hw = NULL;
if (i < nb_freqs)
ret = 0;
else if (closest_below >= 0)
rate = freqs[closest_below].cpll;
else if (closest_above >= 0)
rate = freqs[closest_above].cpll;
else
ret = -EINVAL;
pr_debug("%s(rate=%lu) rate=%lu: %d\n", __func__, req->rate, rate, ret);
if (!rate)
req->rate = rate;
return ret;
}

View File

@ -13,6 +13,11 @@
#ifndef _CLK_PXA_
#define _CLK_PXA_
#define CLKCFG_TURBO 0x1
#define CLKCFG_FCS 0x2
#define CLKCFG_HALFTURBO 0x4
#define CLKCFG_FASTBUS 0x8
#define PARENTS(name) \
static const char *const name ## _parents[] __initconst
#define MUX_RO_RATE_RO_OPS(name, clk_name) \
@ -37,7 +42,7 @@
#define RATE_RO_OPS(name, clk_name) \
static struct clk_hw name ## _rate_hw; \
static struct clk_ops name ## _rate_ops = { \
static const struct clk_ops name ## _rate_ops = { \
.recalc_rate = name ## _get_rate, \
}; \
static struct clk * __init clk_register_ ## name(void) \
@ -50,6 +55,41 @@
NULL, NULL, CLK_GET_RATE_NOCACHE); \
}
#define RATE_OPS(name, clk_name) \
static struct clk_hw name ## _rate_hw; \
static struct clk_ops name ## _rate_ops = { \
.recalc_rate = name ## _get_rate, \
.set_rate = name ## _set_rate, \
.determine_rate = name ## _determine_rate, \
}; \
static struct clk * __init clk_register_ ## name(void) \
{ \
return clk_register_composite(NULL, clk_name, \
name ## _parents, \
ARRAY_SIZE(name ## _parents), \
NULL, NULL, \
&name ## _rate_hw, &name ## _rate_ops, \
NULL, NULL, CLK_GET_RATE_NOCACHE); \
}
#define MUX_OPS(name, clk_name, flags) \
static struct clk_hw name ## _mux_hw; \
static const struct clk_ops name ## _mux_ops = { \
.get_parent = name ## _get_parent, \
.set_parent = name ## _set_parent, \
.determine_rate = name ## _determine_rate, \
}; \
static struct clk * __init clk_register_ ## name(void) \
{ \
return clk_register_composite(NULL, clk_name, \
name ## _parents, \
ARRAY_SIZE(name ## _parents), \
&name ## _mux_hw, &name ## _mux_ops, \
NULL, NULL, \
NULL, NULL, \
CLK_GET_RATE_NOCACHE | flags); \
}
/*
* CKEN clock type
* This clock takes it source from 2 possible parents :
@ -95,6 +135,14 @@ struct desc_clk_cken {
PXA_CKEN(dev_id, con_id, name, parents, 1, 1, 1, 1, \
NULL, cken_reg, cken_bit, flag)
struct pxa2xx_freq {
unsigned long cpll;
unsigned int membus_khz;
unsigned int cccr;
unsigned int div2;
unsigned int clkcfg;
};
static int dummy_clk_set_parent(struct clk_hw *hw, u8 index)
{
return 0;
@ -105,4 +153,11 @@ extern void clkdev_pxa_register(int ckid, const char *con_id,
extern int clk_pxa_cken_init(const struct desc_clk_cken *clks, int nb_clks);
void clk_pxa_dt_common_init(struct device_node *np);
void pxa2xx_core_turbo_switch(bool on);
void pxa2xx_cpll_change(struct pxa2xx_freq *freq,
u32 (*mdrefr_dri)(unsigned int), u32 *mdrefr,
u32 *cccr);
int pxa2xx_determine_rate(struct clk_rate_request *req,
struct pxa2xx_freq *freqs, int nb_freqs);
#endif

View File

@ -18,6 +18,7 @@
#include <linux/io.h>
#include <linux/of.h>
#include <mach/pxa2xx-regs.h>
#include <mach/smemc.h>
#include <dt-bindings/clock/pxa-clock.h>
#include "clk-pxa.h"
@ -30,6 +31,17 @@ enum {
PXA_CORE_TURBO,
};
#define PXA25x_CLKCFG(T) \
(CLKCFG_FCS | \
((T) ? CLKCFG_TURBO : 0))
#define PXA25x_CCCR(N2, M, L) (N2 << 7 | M << 5 | L)
#define MDCNFG_DRAC2(mdcnfg) (((mdcnfg) >> 21) & 0x3)
#define MDCNFG_DRAC0(mdcnfg) (((mdcnfg) >> 5) & 0x3)
/* Define the refresh period in mSec for the SDRAM and the number of rows */
#define SDRAM_TREF 64 /* standard 64ms SDRAM */
/*
* Various clock factors driven by the CCCR register.
*/
@ -48,6 +60,34 @@ static const char * const get_freq_khz[] = {
"core", "run", "cpll", "memory"
};
static int get_sdram_rows(void)
{
static int sdram_rows;
unsigned int drac2 = 0, drac0 = 0;
u32 mdcnfg;
if (sdram_rows)
return sdram_rows;
mdcnfg = readl_relaxed(MDCNFG);
if (mdcnfg & (MDCNFG_DE2 | MDCNFG_DE3))
drac2 = MDCNFG_DRAC2(mdcnfg);
if (mdcnfg & (MDCNFG_DE0 | MDCNFG_DE1))
drac0 = MDCNFG_DRAC0(mdcnfg);
sdram_rows = 1 << (11 + max(drac0, drac2));
return sdram_rows;
}
static u32 mdrefr_dri(unsigned int freq_khz)
{
u32 interval = freq_khz * SDRAM_TREF / get_sdram_rows();
return interval / 32;
}
/*
* Get the clock frequency as reflected by CCCR and the turbo flag.
* We assume these values have been applied via a fcs.
@ -139,6 +179,21 @@ static struct desc_clk_cken pxa25x_clocks[] __initdata = {
clk_pxa25x_memory_parents, 0),
};
/*
* In this table, PXA25x_CCCR(N2, M, L) has the following meaning, where :
* - freq_cpll = n * m * L * 3.6864 MHz
* - n = N2 / 2
* - m = 2^(M - 1), where 1 <= M <= 3
* - l = L_clk_mult[L], ie. { 0, 27, 32, 36, 40, 45, 0, }[L]
*/
static struct pxa2xx_freq pxa25x_freqs[] = {
/* CPU MEMBUS CCCR DIV2 CCLKCFG */
{ 99532800, 99500, PXA25x_CCCR(2, 1, 1), 1, PXA25x_CLKCFG(1)},
{199065600, 99500, PXA25x_CCCR(4, 1, 1), 0, PXA25x_CLKCFG(1)},
{298598400, 99500, PXA25x_CCCR(3, 2, 1), 0, PXA25x_CLKCFG(1)},
{398131200, 99500, PXA25x_CCCR(4, 2, 1), 0, PXA25x_CLKCFG(1)},
};
static u8 clk_pxa25x_core_get_parent(struct clk_hw *hw)
{
unsigned long clkcfg;
@ -151,13 +206,24 @@ static u8 clk_pxa25x_core_get_parent(struct clk_hw *hw)
return PXA_CORE_RUN;
}
static unsigned long clk_pxa25x_core_get_rate(struct clk_hw *hw,
unsigned long parent_rate)
static int clk_pxa25x_core_set_parent(struct clk_hw *hw, u8 index)
{
return parent_rate;
if (index > PXA_CORE_TURBO)
return -EINVAL;
pxa2xx_core_turbo_switch(index == PXA_CORE_TURBO);
return 0;
}
static int clk_pxa25x_core_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
return __clk_mux_determine_rate(hw, req);
}
PARENTS(clk_pxa25x_core) = { "run", "cpll" };
MUX_RO_RATE_RO_OPS(clk_pxa25x_core, "core");
MUX_OPS(clk_pxa25x_core, "core", CLK_SET_RATE_PARENT);
static unsigned long clk_pxa25x_run_get_rate(struct clk_hw *hw,
unsigned long parent_rate)
@ -184,8 +250,33 @@ static unsigned long clk_pxa25x_cpll_get_rate(struct clk_hw *hw,
return m * l * n2 * parent_rate / 2;
}
static int clk_pxa25x_cpll_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
return pxa2xx_determine_rate(req, pxa25x_freqs,
ARRAY_SIZE(pxa25x_freqs));
}
static int clk_pxa25x_cpll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
int i;
pr_debug("%s(rate=%lu parent_rate=%lu)\n", __func__, rate, parent_rate);
for (i = 0; i < ARRAY_SIZE(pxa25x_freqs); i++)
if (pxa25x_freqs[i].cpll == rate)
break;
if (i >= ARRAY_SIZE(pxa25x_freqs))
return -EINVAL;
pxa2xx_cpll_change(&pxa25x_freqs[i], mdrefr_dri, MDREFR, CCCR);
return 0;
}
PARENTS(clk_pxa25x_cpll) = { "osc_3_6864mhz" };
RATE_RO_OPS(clk_pxa25x_cpll, "cpll");
RATE_OPS(clk_pxa25x_cpll, "cpll");
static void __init pxa25x_register_core(void)
{

View File

@ -17,6 +17,8 @@
#include <linux/clkdev.h>
#include <linux/of.h>
#include <mach/smemc.h>
#include <dt-bindings/clock/pxa-clock.h>
#include "clk-pxa.h"
@ -45,11 +47,52 @@ enum {
PXA_MEM_RUN,
};
#define PXA27x_CLKCFG(B, HT, T) \
(CLKCFG_FCS | \
((B) ? CLKCFG_FASTBUS : 0) | \
((HT) ? CLKCFG_HALFTURBO : 0) | \
((T) ? CLKCFG_TURBO : 0))
#define PXA27x_CCCR(A, L, N2) (A << 25 | N2 << 7 | L)
#define MDCNFG_DRAC2(mdcnfg) (((mdcnfg) >> 21) & 0x3)
#define MDCNFG_DRAC0(mdcnfg) (((mdcnfg) >> 5) & 0x3)
/* Define the refresh period in mSec for the SDRAM and the number of rows */
#define SDRAM_TREF 64 /* standard 64ms SDRAM */
static const char * const get_freq_khz[] = {
"core", "run", "cpll", "memory",
"system_bus"
};
static int get_sdram_rows(void)
{
static int sdram_rows;
unsigned int drac2 = 0, drac0 = 0;
u32 mdcnfg;
if (sdram_rows)
return sdram_rows;
mdcnfg = readl_relaxed(MDCNFG);
if (mdcnfg & (MDCNFG_DE2 | MDCNFG_DE3))
drac2 = MDCNFG_DRAC2(mdcnfg);
if (mdcnfg & (MDCNFG_DE0 | MDCNFG_DE1))
drac0 = MDCNFG_DRAC0(mdcnfg);
sdram_rows = 1 << (11 + max(drac0, drac2));
return sdram_rows;
}
static u32 mdrefr_dri(unsigned int freq_khz)
{
u32 interval = freq_khz * SDRAM_TREF / get_sdram_rows();
return (interval - 31) / 32;
}
/*
* Get the clock frequency as reflected by CCSR and the turbo flag.
* We assume these values have been applied via a fcs.
@ -145,6 +188,42 @@ static struct desc_clk_cken pxa27x_clocks[] __initdata = {
};
/*
* PXA270 definitions
*
* For the PXA27x:
* Control variables are A, L, 2N for CCCR; B, HT, T for CLKCFG.
*
* A = 0 => memory controller clock from table 3-7,
* A = 1 => memory controller clock = system bus clock
* Run mode frequency = 13 MHz * L
* Turbo mode frequency = 13 MHz * L * N
* System bus frequency = 13 MHz * L / (B + 1)
*
* In CCCR:
* A = 1
* L = 16 oscillator to run mode ratio
* 2N = 6 2 * (turbo mode to run mode ratio)
*
* In CCLKCFG:
* B = 1 Fast bus mode
* HT = 0 Half-Turbo mode
* T = 1 Turbo mode
*
* For now, just support some of the combinations in table 3-7 of
* PXA27x Processor Family Developer's Manual to simplify frequency
* change sequences.
*/
static struct pxa2xx_freq pxa27x_freqs[] = {
{104000000, 104000, PXA27x_CCCR(1, 8, 2), 0, PXA27x_CLKCFG(1, 0, 1) },
{156000000, 104000, PXA27x_CCCR(1, 8, 3), 0, PXA27x_CLKCFG(1, 0, 1) },
{208000000, 208000, PXA27x_CCCR(0, 16, 2), 1, PXA27x_CLKCFG(0, 0, 1) },
{312000000, 208000, PXA27x_CCCR(1, 16, 3), 1, PXA27x_CLKCFG(1, 0, 1) },
{416000000, 208000, PXA27x_CCCR(1, 16, 4), 1, PXA27x_CLKCFG(1, 0, 1) },
{520000000, 208000, PXA27x_CCCR(1, 16, 5), 1, PXA27x_CLKCFG(1, 0, 1) },
{624000000, 208000, PXA27x_CCCR(1, 16, 6), 1, PXA27x_CLKCFG(1, 0, 1) },
};
static unsigned long clk_pxa27x_cpll_get_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
@ -164,8 +243,33 @@ static unsigned long clk_pxa27x_cpll_get_rate(struct clk_hw *hw,
return N;
}
static int clk_pxa27x_cpll_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
return pxa2xx_determine_rate(req, pxa27x_freqs,
ARRAY_SIZE(pxa27x_freqs));
}
static int clk_pxa27x_cpll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
int i;
pr_debug("%s(rate=%lu parent_rate=%lu)\n", __func__, rate, parent_rate);
for (i = 0; i < ARRAY_SIZE(pxa27x_freqs); i++)
if (pxa27x_freqs[i].cpll == rate)
break;
if (i >= ARRAY_SIZE(pxa27x_freqs))
return -EINVAL;
pxa2xx_cpll_change(&pxa27x_freqs[i], mdrefr_dri, MDREFR, CCCR);
return 0;
}
PARENTS(clk_pxa27x_cpll) = { "osc_13mhz" };
RATE_RO_OPS(clk_pxa27x_cpll, "cpll");
RATE_OPS(clk_pxa27x_cpll, "cpll");
static unsigned long clk_pxa27x_lcd_base_get_rate(struct clk_hw *hw,
unsigned long parent_rate)
@ -217,25 +321,6 @@ static void __init pxa27x_register_plls(void)
clk_register_fixed_factor(NULL, "ppll_312mhz", "osc_13mhz", 0, 24, 1);
}
static unsigned long clk_pxa27x_core_get_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
unsigned long clkcfg;
unsigned int ht, osc_forced;
unsigned long ccsr = readl(CCSR);
osc_forced = ccsr & (1 << CCCR_CPDIS_BIT);
asm("mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
ht = clkcfg & (1 << 2);
if (osc_forced)
return parent_rate;
if (ht)
return parent_rate / 2;
else
return parent_rate;
}
static u8 clk_pxa27x_core_get_parent(struct clk_hw *hw)
{
unsigned long clkcfg;
@ -254,8 +339,25 @@ static u8 clk_pxa27x_core_get_parent(struct clk_hw *hw)
return PXA_CORE_TURBO;
return PXA_CORE_RUN;
}
static int clk_pxa27x_core_set_parent(struct clk_hw *hw, u8 index)
{
if (index > PXA_CORE_TURBO)
return -EINVAL;
pxa2xx_core_turbo_switch(index == PXA_CORE_TURBO);
return 0;
}
static int clk_pxa27x_core_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
return __clk_mux_determine_rate(hw, req);
}
PARENTS(clk_pxa27x_core) = { "osc_13mhz", "run", "cpll" };
MUX_RO_RATE_RO_OPS(clk_pxa27x_core, "core");
MUX_OPS(clk_pxa27x_core, "core", CLK_SET_RATE_PARENT);
static unsigned long clk_pxa27x_run_get_rate(struct clk_hw *hw,
unsigned long parent_rate)