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clk: samsung: Add support for EPLL on exynos5410

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This patch adds code instantiating the EPLL, which is used as the
audio subsystem's root clock.
The requirement to specify the external root clock in clocks property
is documented.  Having the consumer 'clocks' property ensures proper
initialization order by explicitly specifying dependencies in DT.
It prevents situations when the SoC's clock controller driver has
initialized, the external oscillator clock is not yet registered
and setting clock frequencies through assigned-clock-rates property
doesn't work properly due to unknown external oscillator frequency.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
This commit is contained in:
Sylwester Nawrocki 2016-09-09 10:09:05 +02:00
parent c17a616364
commit be95d2c7d9
4 changed files with 144 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
Documentation/devicetree/bindings/clock/exynos5410-clock.txt
View File

@ -12,24 +12,29 @@ Required Properties:
- #clock-cells: should be 1.
- clocks: should contain an entry specifying the root clock from external
oscillator supplied through XXTI or XusbXTI pin. This clock should be
defined using standard clock bindings with "fin_pll" clock-output-name.
That clock is being passed internally to the 9 PLLs.
All available clocks are defined as preprocessor macros in
dt-bindings/clock/exynos5410.h header and can be used in device
tree sources.
External clock:
There is clock that is generated outside the SoC. It
is expected that it is defined using standard clock bindings
with following clock-output-name:
- "fin_pll" - PLL input clock from XXTI
Example 1: An example of a clock controller node is listed below.
fin_pll: xxti {
compatible = "fixed-clock";
clock-frequency = <24000000>;
clock-output-names = "fin_pll";
#clock-cells = <0>;
};
clock: clock-controller@0x10010000 {
compatible = "samsung,exynos5410-clock";
reg = <0x10010000 0x30000>;
#clock-cells = <1>;
clocks = <&fin_pll>;
};
Example 2: UART controller node that consumes the clock generated by the clock

30
drivers/clk/samsung/clk-exynos5410.c
View File

@ -14,6 +14,7 @@
#include <linux/clk-provider.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/clk.h>
#include "clk.h"
@ -21,6 +22,8 @@
#define APLL_CON0 0x100
#define CPLL_LOCK 0x10020
#define CPLL_CON0 0x10120
#define EPLL_LOCK 0x10040
#define EPLL_CON0 0x10130
#define MPLL_LOCK 0x4000
#define MPLL_CON0 0x4100
#define BPLL_LOCK 0x20010
@ -58,7 +61,7 @@
/* list of PLLs */
enum exynos5410_plls {
apll, cpll, mpll,
apll, cpll, epll, mpll,
bpll, kpll,
nr_plls /* number of PLLs */
};
@ -67,6 +70,7 @@ enum exynos5410_plls {
PNAME(apll_p) = { "fin_pll", "fout_apll", };
PNAME(bpll_p) = { "fin_pll", "fout_bpll", };
PNAME(cpll_p) = { "fin_pll", "fout_cpll" };
PNAME(epll_p) = { "fin_pll", "fout_epll" };
PNAME(mpll_p) = { "fin_pll", "fout_mpll", };
PNAME(kpll_p) = { "fin_pll", "fout_kpll", };
@ -95,6 +99,8 @@ static const struct samsung_mux_clock exynos5410_mux_clks[] __initconst = {
MUX(0, "sclk_bpll", bpll_p, SRC_CDREX, 0, 1),
MUX(0, "sclk_bpll_muxed", bpll_user_p, SRC_TOP2, 24, 1),
MUX(0, "sclk_epll", epll_p, SRC_TOP2, 12, 1),
MUX(0, "sclk_cpll", cpll_p, SRC_TOP2, 8, 1),
MUX(0, "sclk_mpll_bpll", mpll_bpll_p, SRC_TOP1, 20, 1),
@ -219,11 +225,26 @@ static const struct samsung_gate_clock exynos5410_gate_clks[] __initconst = {
GATE(CLK_USBD301, "usbd301", "aclk200_fsys", GATE_IP_FSYS, 20, 0, 0),
};
static const struct samsung_pll_clock exynos5410_plls[nr_plls] __initconst = {
static const struct samsung_pll_rate_table exynos5410_pll2550x_24mhz_tbl[] __initconst = {
PLL_36XX_RATE(400000000U, 200, 3, 2, 0),
PLL_36XX_RATE(333000000U, 111, 2, 2, 0),
PLL_36XX_RATE(300000000U, 100, 2, 2, 0),
PLL_36XX_RATE(266000000U, 266, 3, 3, 0),
PLL_36XX_RATE(200000000U, 200, 3, 3, 0),
PLL_36XX_RATE(192000000U, 192, 3, 3, 0),
PLL_36XX_RATE(166000000U, 166, 3, 3, 0),
PLL_36XX_RATE(133000000U, 266, 3, 4, 0),
PLL_36XX_RATE(100000000U, 200, 3, 4, 0),
PLL_36XX_RATE(66000000U, 176, 2, 5, 0),
};
static struct samsung_pll_clock exynos5410_plls[nr_plls] __initdata = {
[apll] = PLL(pll_35xx, CLK_FOUT_APLL, "fout_apll", "fin_pll", APLL_LOCK,
APLL_CON0, NULL),
[cpll] = PLL(pll_35xx, CLK_FOUT_CPLL, "fout_cpll", "fin_pll", CPLL_LOCK,
CPLL_CON0, NULL),
[epll] = PLL(pll_2650x, CLK_FOUT_EPLL, "fout_epll", "fin_pll", EPLL_LOCK,
EPLL_CON0, NULL),
[mpll] = PLL(pll_35xx, CLK_FOUT_MPLL, "fout_mpll", "fin_pll", MPLL_LOCK,
MPLL_CON0, NULL),
[bpll] = PLL(pll_35xx, CLK_FOUT_BPLL, "fout_bpll", "fin_pll", BPLL_LOCK,
@ -247,6 +268,11 @@ static const struct samsung_cmu_info cmu __initconst = {
/* register exynos5410 clocks */
static void __init exynos5410_clk_init(struct device_node *np)
{
struct clk *xxti = of_clk_get(np, 0);
if (!IS_ERR(xxti) && clk_get_rate(xxti) == 24 * MHZ)
exynos5410_plls[epll].rate_table = exynos5410_pll2550x_24mhz_tbl;
samsung_cmu_register_one(np, &cmu);
pr_debug("Exynos5410: clock setup completed.\n");

102
drivers/clk/samsung/clk-pll.c
View File

@ -1017,6 +1017,102 @@ static const struct clk_ops samsung_pll2550xx_clk_min_ops = {
.recalc_rate = samsung_pll2550xx_recalc_rate,
};
/*
* PLL2650x Clock Type
*/
/* Maximum lock time can be 3000 * PDIV cycles */
#define PLL2650X_LOCK_FACTOR 3000
#define PLL2650X_M_MASK 0x1ff
#define PLL2650X_P_MASK 0x3f
#define PLL2650X_S_MASK 0x7
#define PLL2650X_K_MASK 0xffff
#define PLL2650X_LOCK_STAT_MASK 0x1
#define PLL2650X_M_SHIFT 16
#define PLL2650X_P_SHIFT 8
#define PLL2650X_S_SHIFT 0
#define PLL2650X_K_SHIFT 0
#define PLL2650X_LOCK_STAT_SHIFT 29
#define PLL2650X_PLL_ENABLE_SHIFT 31
static unsigned long samsung_pll2650x_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct samsung_clk_pll *pll = to_clk_pll(hw);
u64 fout = parent_rate;
u32 mdiv, pdiv, sdiv, pll_con0, pll_con1;
s16 kdiv;
pll_con0 = readl_relaxed(pll->con_reg);
mdiv = (pll_con0 >> PLL2650X_M_SHIFT) & PLL2650X_M_MASK;
pdiv = (pll_con0 >> PLL2650X_P_SHIFT) & PLL2650X_P_MASK;
sdiv = (pll_con0 >> PLL2650X_S_SHIFT) & PLL2650X_S_MASK;
pll_con1 = readl_relaxed(pll->con_reg + 4);
kdiv = (s16)((pll_con1 >> PLL2650X_K_SHIFT) & PLL2650X_K_MASK);
fout *= (mdiv << 16) + kdiv;
do_div(fout, (pdiv << sdiv));
fout >>= 16;
return (unsigned long)fout;
}
static int samsung_pll2650x_set_rate(struct clk_hw *hw, unsigned long drate,
unsigned long prate)
{
struct samsung_clk_pll *pll = to_clk_pll(hw);
const struct samsung_pll_rate_table *rate;
u32 con0, con1;
/* Get required rate settings from table */
rate = samsung_get_pll_settings(pll, drate);
if (!rate) {
pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
drate, clk_hw_get_name(hw));
return -EINVAL;
}
con0 = readl_relaxed(pll->con_reg);
con1 = readl_relaxed(pll->con_reg + 4);
/* Set PLL lock time. */
writel_relaxed(rate->pdiv * PLL2650X_LOCK_FACTOR, pll->lock_reg);
/* Change PLL PMS values */
con0 &= ~((PLL2650X_M_MASK << PLL2650X_M_SHIFT) |
(PLL2650X_P_MASK << PLL2650X_P_SHIFT) |
(PLL2650X_S_MASK << PLL2650X_S_SHIFT));
con0 |= (rate->mdiv << PLL2650X_M_SHIFT) |
(rate->pdiv << PLL2650X_P_SHIFT) |
(rate->sdiv << PLL2650X_S_SHIFT);
con0 |= (1 << PLL2650X_PLL_ENABLE_SHIFT);
writel_relaxed(con0, pll->con_reg);
con1 &= ~(PLL2650X_K_MASK << PLL2650X_K_SHIFT);
con1 |= ((rate->kdiv & PLL2650X_K_MASK) << PLL2650X_K_SHIFT);
writel_relaxed(con1, pll->con_reg + 4);
do {
cpu_relax();
con0 = readl_relaxed(pll->con_reg);
} while (!(con0 & (PLL2650X_LOCK_STAT_MASK
<< PLL2650X_LOCK_STAT_SHIFT)));
return 0;
}
static const struct clk_ops samsung_pll2650x_clk_ops = {
.recalc_rate = samsung_pll2650x_recalc_rate,
.round_rate = samsung_pll_round_rate,
.set_rate = samsung_pll2650x_set_rate,
};
static const struct clk_ops samsung_pll2650x_clk_min_ops = {
.recalc_rate = samsung_pll2650x_recalc_rate,
};
/*
* PLL2650XX Clock Type
*/
@ -1227,6 +1323,12 @@ static void __init _samsung_clk_register_pll(struct samsung_clk_provider *ctx,
else
init.ops = &samsung_pll2550xx_clk_ops;
break;
case pll_2650x:
if (!pll->rate_table)
init.ops = &samsung_pll2650x_clk_min_ops;
else
init.ops = &samsung_pll2650x_clk_ops;
break;
case pll_2650xx:
if (!pll->rate_table)
init.ops = &samsung_pll2650xx_clk_min_ops;

1
drivers/clk/samsung/clk-pll.h
View File

@ -33,6 +33,7 @@ enum samsung_pll_type {
pll_s3c2440_mpll,
pll_2550x,
pll_2550xx,
pll_2650x,
pll_2650xx,
pll_1450x,
pll_1451x,