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clk: versatile/icst: add Integrator core module clocks

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The Integrator/AP and Integrator/CP have special derivatives
of the ICST525 control registers, where some bits have been
hardwired but others are possible to adjust, resulting in a
control register that makes it possible to set an even,
desired megahertz value.

The Integrator/AP and Integrator/CP have slightly different
layout so we support them using different compatible
strings.

After adding these clocks, the Integrator-specific cpufreq
driver can be switched over to use the generic operating
point device tree cpufreq driver.

Instead of simply writing a value to the oscillator control
register we switch to the more elaborate method of providing
a bitmask and use regmap_update_bits() to poke the right bits
for the desired frequency, this is needed since these control
registers sometimes control more than one clock.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This commit is contained in:
Linus Walleij 2016-08-22 11:19:33 +02:00 committed by Stephen Boyd
parent 50581cc4f1
commit 5e23c59305
1 changed files with 160 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

174
drivers/clk/versatile/clk-icst.c
View File

@ -27,6 +27,21 @@
/* Magic unlocking token used on all Versatile boards */
#define VERSATILE_LOCK_VAL 0xA05F
#define VERSATILE_AUX_OSC_BITS 0x7FFFF
#define INTEGRATOR_AP_CM_BITS 0xFF
#define INTEGRATOR_CP_CM_CORE_BITS 0x7FF
#define INTEGRATOR_CP_CM_MEM_BITS 0x7FF000
/**
* enum icst_control_type - the type of ICST control register
*/
enum icst_control_type {
ICST_VERSATILE, /* The standard type, all control bits available */
ICST_INTEGRATOR_AP_CM, /* Only 8 bits of VDW available */
ICST_INTEGRATOR_CP_CM_CORE, /* Only 8 bits of VDW and 3 bits of OD */
ICST_INTEGRATOR_CP_CM_MEM, /* Only 8 bits of VDW and 3 bits of OD */
};
/**
* struct clk_icst - ICST VCO clock wrapper
* @hw: corresponding clock hardware entry
@ -34,6 +49,7 @@
* @lockreg: VCO lock register address
* @params: parameters for this ICST instance
* @rate: current rate
* @ctype: the type of control register for the ICST
*/
struct clk_icst {
struct clk_hw hw;
@ -42,6 +58,7 @@ struct clk_icst {
u32 lockreg_off;
struct icst_params *params;
unsigned long rate;
enum icst_control_type ctype;
};
#define to_icst(_hw) container_of(_hw, struct clk_icst, hw)
@ -59,6 +76,44 @@ static int vco_get(struct clk_icst *icst, struct icst_vco *vco)
ret = regmap_read(icst->map, icst->vcoreg_off, &val);
if (ret)
return ret;
/*
* The Integrator/AP core clock can only access the low eight
* bits of the v PLL divider. Bit 8 is tied low and always zero,
* r is hardwired to 22 and output divider s is hardwired to 1
* (divide by 2) according to the document
* "Integrator CM926EJ-S, CM946E-S, CM966E-S, CM1026EJ-S and
* CM1136JF-S User Guide" ARM DUI 0138E, page 3-13 thru 3-14.
*/
if (icst->ctype == ICST_INTEGRATOR_AP_CM) {
vco->v = val & INTEGRATOR_AP_CM_BITS;
vco->r = 22;
vco->s = 1;
return 0;
}
/*
* The Integrator/CP core clock can access the low eight bits
* of the v PLL divider. Bit 8 is tied low and always zero,
* r is hardwired to 22 and the output divider s is accessible
* in bits 8 thru 10 according to the document
* "Integrator/CM940T, CM920T, CM740T, and CM720T User Guide"
* ARM DUI 0157A, page 3-20 thru 3-23 and 4-10.
*/
if (icst->ctype == ICST_INTEGRATOR_CP_CM_CORE) {
vco->v = val & 0xFF;
vco->r = 22;
vco->s = (val >> 8) & 7;
return 0;
}
if (icst->ctype == ICST_INTEGRATOR_CP_CM_MEM) {
vco->v = (val >> 12) & 0xFF;
vco->r = 22;
vco->s = (val >> 20) & 7;
return 0;
}
vco->v = val & 0x1ff;
vco->r = (val >> 9) & 0x7f;
vco->s = (val >> 16) & 03;
@ -72,22 +127,52 @@ static int vco_get(struct clk_icst *icst, struct icst_vco *vco)
*/
static int vco_set(struct clk_icst *icst, struct icst_vco vco)
{
u32 mask;
u32 val;
int ret;
ret = regmap_read(icst->map, icst->vcoreg_off, &val);
if (ret)
return ret;
/* Mask the bits used by the VCO */
switch (icst->ctype) {
case ICST_INTEGRATOR_AP_CM:
mask = INTEGRATOR_AP_CM_BITS;
val = vco.v & 0xFF;
if (vco.v & 0x100)
pr_err("ICST error: tried to set bit 8 of VDW\n");
if (vco.s != 1)
pr_err("ICST error: tried to use VOD != 1\n");
if (vco.r != 22)
pr_err("ICST error: tried to use RDW != 22\n");
break;
case ICST_INTEGRATOR_CP_CM_CORE:
mask = INTEGRATOR_CP_CM_CORE_BITS; /* Uses 12 bits */
val = (vco.v & 0xFF) | vco.s << 8;
if (vco.v & 0x100)
pr_err("ICST error: tried to set bit 8 of VDW\n");
if (vco.r != 22)
pr_err("ICST error: tried to use RDW != 22\n");
break;
case ICST_INTEGRATOR_CP_CM_MEM:
mask = INTEGRATOR_CP_CM_MEM_BITS; /* Uses 12 bits */
val = ((vco.v & 0xFF) << 12) | (vco.s << 20);
if (vco.v & 0x100)
pr_err("ICST error: tried to set bit 8 of VDW\n");
if (vco.r != 22)
pr_err("ICST error: tried to use RDW != 22\n");
break;
default:
/* Regular auxilary oscillator */
mask = VERSATILE_AUX_OSC_BITS;
val = vco.v | (vco.r << 9) | (vco.s << 16);
break;
}
/* Mask the 18 bits used by the VCO */
val &= ~0x7ffff;
val |= vco.v | (vco.r << 9) | (vco.s << 16);
pr_debug("ICST: new val = 0x%08x\n", val);
/* This magic unlocks the VCO so it can be controlled */
ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL);
if (ret)
return ret;
ret = regmap_write(icst->map, icst->vcoreg_off, val);
ret = regmap_update_bits(icst->map, icst->vcoreg_off, mask, val);
if (ret)
return ret;
/* This locks the VCO again */
@ -121,6 +206,25 @@ static long icst_round_rate(struct clk_hw *hw, unsigned long rate,
struct clk_icst *icst = to_icst(hw);
struct icst_vco vco;
if (icst->ctype == ICST_INTEGRATOR_AP_CM ||
icst->ctype == ICST_INTEGRATOR_CP_CM_CORE) {
if (rate <= 12000000)
return 12000000;
if (rate >= 160000000)
return 160000000;
/* Slam to closest megahertz */
return DIV_ROUND_CLOSEST(rate, 1000000) * 1000000;
}
if (icst->ctype == ICST_INTEGRATOR_CP_CM_MEM) {
if (rate <= 6000000)
return 6000000;
if (rate >= 66000000)
return 66000000;
/* Slam to closest 0.5 megahertz */
return DIV_ROUND_CLOSEST(rate, 500000) * 500000;
}
vco = icst_hz_to_vco(icst->params, rate);
return icst_hz(icst->params, vco);
}
@ -148,7 +252,8 @@ static struct clk *icst_clk_setup(struct device *dev,
const struct clk_icst_desc *desc,
const char *name,
const char *parent_name,
struct regmap *map)
struct regmap *map,
enum icst_control_type ctype)
{
struct clk *clk;
struct clk_icst *icst;
@ -178,6 +283,7 @@ static struct clk *icst_clk_setup(struct device *dev,
icst->params = pclone;
icst->vcoreg_off = desc->vco_offset;
icst->lockreg_off = desc->lock_offset;
icst->ctype = ctype;
clk = clk_register(dev, &icst->hw);
if (IS_ERR(clk)) {
@ -206,7 +312,8 @@ struct clk *icst_clk_register(struct device *dev,
pr_err("could not initialize ICST regmap\n");
return ERR_CAST(map);
}
return icst_clk_setup(dev, desc, name, parent_name, map);
return icst_clk_setup(dev, desc, name, parent_name, map,
ICST_VERSATILE);
}
EXPORT_SYMBOL_GPL(icst_clk_register);
@ -239,6 +346,28 @@ static const struct icst_params icst307_params = {
.idx2s = icst307_idx2s,
};
/**
* The core modules on the Integrator/AP and Integrator/CP have
* especially crippled ICST525 control.
*/
static const struct icst_params icst525_apcp_cm_params = {
.vco_max = ICST525_VCO_MAX_5V,
.vco_min = ICST525_VCO_MIN,
/* Minimum 12 MHz, VDW = 4 */
.vd_min = 12,
/*
* Maximum 160 MHz, VDW = 152 for all core modules, but
* CM926EJ-S, CM1026EJ-S and CM1136JF-S can actually
* go to 200 MHz (max VDW = 192).
*/
.vd_max = 192,
/* r is hardcoded to 22 and this is the actual divisor, +2 */
.rd_min = 24,
.rd_max = 24,
.s2div = icst525_s2div,
.idx2s = icst525_idx2s,
};
static void __init of_syscon_icst_setup(struct device_node *np)
{
struct device_node *parent;
@ -247,6 +376,7 @@ static void __init of_syscon_icst_setup(struct device_node *np)
const char *name = np->name;
const char *parent_name;
struct clk *regclk;
enum icst_control_type ctype;
/* We do not release this reference, we are using it perpetually */
parent = of_get_parent(np);
@ -269,11 +399,22 @@ static void __init of_syscon_icst_setup(struct device_node *np)
return;
}
if (of_device_is_compatible(np, "arm,syscon-icst525"))
if (of_device_is_compatible(np, "arm,syscon-icst525")) {
icst_desc.params = &icst525_params;
else if (of_device_is_compatible(np, "arm,syscon-icst307"))
ctype = ICST_VERSATILE;
} else if (of_device_is_compatible(np, "arm,syscon-icst307")) {
icst_desc.params = &icst307_params;
else {
ctype = ICST_VERSATILE;
} else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-cm")) {
icst_desc.params = &icst525_apcp_cm_params;
ctype = ICST_INTEGRATOR_AP_CM;
} else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorcp-cm-core")) {
icst_desc.params = &icst525_apcp_cm_params;
ctype = ICST_INTEGRATOR_CP_CM_CORE;
} else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorcp-cm-mem")) {
icst_desc.params = &icst525_apcp_cm_params;
ctype = ICST_INTEGRATOR_CP_CM_MEM;
} else {
pr_err("unknown ICST clock %s\n", name);
return;
}
@ -281,7 +422,7 @@ static void __init of_syscon_icst_setup(struct device_node *np)
/* Parent clock name is not the same as node parent */
parent_name = of_clk_get_parent_name(np, 0);
regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map);
regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map, ctype);
if (IS_ERR(regclk)) {
pr_err("error setting up syscon ICST clock %s\n", name);
return;
@ -294,5 +435,10 @@ CLK_OF_DECLARE(arm_syscon_icst525_clk,
"arm,syscon-icst525", of_syscon_icst_setup);
CLK_OF_DECLARE(arm_syscon_icst307_clk,
"arm,syscon-icst307", of_syscon_icst_setup);
CLK_OF_DECLARE(arm_syscon_integratorap_cm_clk,
"arm,syscon-icst525-integratorap-cm", of_syscon_icst_setup);
CLK_OF_DECLARE(arm_syscon_integratorcp_cm_core_clk,
"arm,syscon-icst525-integratorcp-cm-core", of_syscon_icst_setup);
CLK_OF_DECLARE(arm_syscon_integratorcp_cm_mem_clk,
"arm,syscon-icst525-integratorcp-cm-mem", of_syscon_icst_setup);
#endif