/*
* Driver for the ICST307 VCO clock found in the ARM Reference designs.
* We wrap the custom interface from <asm/hardware/icst.h> into the generic
* clock framework.
*
* Copyright (C) 2012-2015 Linus Walleij
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* TODO: when all ARM reference designs are migrated to generic clocks, the
* ICST clock code from the ARM tree should probably be merged into this
* file.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include "icst.h"
#include "clk-icst.h"
/* 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_AP_SYS_BITS 0xFF
#define INTEGRATOR_CP_CM_CORE_BITS 0x7FF
#define INTEGRATOR_CP_CM_MEM_BITS 0x7FF000
#define INTEGRATOR_AP_PCI_25_33_MHZ BIT(8)
/**
* 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_AP_SYS, /* Only 8 bits of VDW available */
ICST_INTEGRATOR_AP_PCI, /* Odd bit pattern storage */
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
* @vcoreg: VCO register address
* @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;
struct regmap *map;
u32 vcoreg_off;
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)
/**
* vco_get() - get ICST VCO settings from a certain ICST
* @icst: the ICST clock to get
* @vco: the VCO struct to return the value in
*/
static int vco_get(struct clk_icst *icst, struct icst_vco *vco)
{
u32 val;
int ret;
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/AP system clock on the base board can only
* access the low eight bits of the v PLL divider. Bit 8 is tied low
* and always zero, r is hardwired to 46, and the output divider is
* hardwired to 3 (divide by 4) according to the document
* "Integrator AP ASIC Development Motherboard" ARM DUI 0098B,
* page 3-16.
*/
if (icst->ctype == ICST_INTEGRATOR_AP_SYS) {
vco->v = val & INTEGRATOR_AP_SYS_BITS;
vco->r = 46;
vco->s = 3;
return 0;
}
/*
* The Integrator/AP PCI clock is using an odd pattern to create
* the child clock, basically a single bit called DIVX/Y is used
* to select between two different hardwired values: setting the
* bit to 0 yields v = 17, r = 22 and OD = 1, whereas setting the
* bit to 1 yields v = 14, r = 14 and OD = 1 giving the frequencies
* 33 or 25 MHz respectively.
*/
if (icst->ctype == ICST_INTEGRATOR_AP_PCI) {
bool divxy = !!(val & INTEGRATOR_AP_PCI_25_33_MHZ);
vco->v = divxy ? 17 : 14;
vco->r = divxy ? 22 : 14;
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;
return 0;
}
/**
* vco_set() - commit changes to an ICST VCO
* @icst: the ICST clock to set
* @vco: the VCO struct to set the changes from
*/
static int vco_set(struct clk_icst *icst, struct icst_vco vco)
{
u32 mask;
u32 val;
int 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_AP_SYS:
mask = INTEGRATOR_AP_SYS_BITS;
val = vco.v & 0xFF;
if (vco.v & 0x100)
pr_err("ICST error: tried to set bit 8 of VDW\n");
if (vco.s != 3)
pr_err("ICST error: tried to use VOD != 1\n");
if (vco.r != 46)
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;
}
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_update_bits(icst->map, icst->vcoreg_off, mask, val);
if (ret)
return ret;
/* This locks the VCO again */
ret = regmap_write(icst->map, icst->lockreg_off, 0);
if (ret)
return ret;
return 0;
}
static unsigned long icst_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_icst *icst = to_icst(hw);
struct icst_vco vco;
int ret;
if (parent_rate)
icst->params->ref = parent_rate;
ret = vco_get(icst, &vco);
if (ret) {
pr_err("ICST: could not get VCO setting\n");
return 0;
}
icst->rate = icst_hz(icst->params, vco);
return icst->rate;
}
static long icst_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
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;
}
if (icst->ctype == ICST_INTEGRATOR_AP_SYS) {
/* Divides between 3 and 50 MHz in steps of 0.25 MHz */
if (rate <= 3000000)
return 3000000;
if (rate >= 50000000)
return 5000000;
/* Slam to closest 0.25 MHz */
return DIV_ROUND_CLOSEST(rate, 250000) * 250000;
}
if (icst->ctype == ICST_INTEGRATOR_AP_PCI) {
/*
* If we're below or less than halfway from 25 to 33 MHz
* select 25 MHz
*/
if (rate <= 25000000 || rate < 29000000)
return 25000000;
/* Else just return the default frequency */
return 33000000;
}
vco = icst_hz_to_vco(icst->params, rate);
return icst_hz(icst->params, vco);
}
static int icst_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_icst *icst = to_icst(hw);
struct icst_vco vco;
if (icst->ctype == ICST_INTEGRATOR_AP_PCI) {
/* This clock is especially primitive */
unsigned int val;
int ret;
if (rate == 25000000) {
val = 0;
} else if (rate == 33000000) {
val = INTEGRATOR_AP_PCI_25_33_MHZ;
} else {
pr_err("ICST: cannot set PCI frequency %lu\n",
rate);
return -EINVAL;
}
ret = regmap_write(icst->map, icst->lockreg_off,
VERSATILE_LOCK_VAL);
if (ret)
return ret;
ret = regmap_update_bits(icst->map, icst->vcoreg_off,
INTEGRATOR_AP_PCI_25_33_MHZ,
val);
if (ret)
return ret;
/* This locks the VCO again */
ret = regmap_write(icst->map, icst->lockreg_off, 0);
if (ret)
return ret;
return 0;
}
if (parent_rate)
icst->params->ref = parent_rate;
vco = icst_hz_to_vco(icst->params, rate);
icst->rate = icst_hz(icst->params, vco);
return vco_set(icst, vco);
}
static const struct clk_ops icst_ops = {
.recalc_rate = icst_recalc_rate,
.round_rate = icst_round_rate,
.set_rate = icst_set_rate,
};
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,
enum icst_control_type ctype)
{
struct clk *clk;
struct clk_icst *icst;
struct clk_init_data init;
struct icst_params *pclone;
icst = kzalloc(sizeof(*icst), GFP_KERNEL);
if (!icst)
return ERR_PTR(-ENOMEM);
pclone = kmemdup(desc->params, sizeof(*pclone), GFP_KERNEL);
if (!pclone) {
kfree(icst);
return ERR_PTR(-ENOMEM);
}
init.name = name;
init.ops = &icst_ops;
init.flags = 0;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
icst->map = map;
icst->hw.init = &init;
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)) {
kfree(pclone);
kfree(icst);
}
return clk;
}
struct clk *icst_clk_register(struct device *dev,
const struct clk_icst_desc *desc,
const char *name,
const char *parent_name,
void __iomem *base)
{
struct regmap_config icst_regmap_conf = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};
struct regmap *map;
map = regmap_init_mmio(dev, base, &icst_regmap_conf);
if (IS_ERR(map)) {
pr_err("could not initialize ICST regmap\n");
return ERR_CAST(map);
}
return icst_clk_setup(dev, desc, name, parent_name, map,
ICST_VERSATILE);
}
EXPORT_SYMBOL_GPL(icst_clk_register);
#ifdef CONFIG_OF
/*
* In a device tree, an memory-mapped ICST clock appear as a child
* of a syscon node. Assume this and probe it only as a child of a
* syscon.
*/
static const struct icst_params icst525_params = {
.vco_max = ICST525_VCO_MAX_5V,
.vco_min = ICST525_VCO_MIN,
.vd_min = 8,
.vd_max = 263,
.rd_min = 3,
.rd_max = 65,
.s2div = icst525_s2div,
.idx2s = icst525_idx2s,
};
static const struct icst_params icst307_params = {
.vco_max = ICST307_VCO_MAX,
.vco_min = ICST307_VCO_MIN,
.vd_min = 4 + 8,
.vd_max = 511 + 8,
.rd_min = 1 + 2,
.rd_max = 127 + 2,
.s2div = icst307_s2div,
.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 const struct icst_params icst525_ap_sys_params = {
.vco_max = ICST525_VCO_MAX_5V,
.vco_min = ICST525_VCO_MIN,
/* Minimum 3 MHz, VDW = 4 */
.vd_min = 3,
/* Maximum 50 MHz, VDW = 192 */
.vd_max = 50,
/* r is hardcoded to 46 and this is the actual divisor, +2 */
.rd_min = 48,
.rd_max = 48,
.s2div = icst525_s2div,
.idx2s = icst525_idx2s,
};
static const struct icst_params icst525_ap_pci_params = {
.vco_max = ICST525_VCO_MAX_5V,
.vco_min = ICST525_VCO_MIN,
/* Minimum 25 MHz */
.vd_min = 25,
/* Maximum 33 MHz */
.vd_max = 33,
/* r is hardcoded to 14 or 22 and this is the actual divisors +2 */
.rd_min = 16,
.rd_max = 24,
.s2div = icst525_s2div,
.idx2s = icst525_idx2s,
};
static void __init of_syscon_icst_setup(struct device_node *np)
{
struct device_node *parent;
struct regmap *map;
struct clk_icst_desc icst_desc;
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);
if (!parent) {
pr_err("no parent node for syscon ICST clock\n");
return;
}
map = syscon_node_to_regmap(parent);
if (IS_ERR(map)) {
pr_err("no regmap for syscon ICST clock parent\n");
return;
}
if (of_property_read_u32(np, "vco-offset", &icst_desc.vco_offset)) {
pr_err("no VCO register offset for ICST clock\n");
return;
}
if (of_property_read_u32(np, "lock-offset", &icst_desc.lock_offset)) {
pr_err("no lock register offset for ICST clock\n");
return;
}
if (of_device_is_compatible(np, "arm,syscon-icst525")) {
icst_desc.params = &icst525_params;
ctype = ICST_VERSATILE;
} else if (of_device_is_compatible(np, "arm,syscon-icst307")) {
icst_desc.params = &icst307_params;
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-integratorap-sys")) {
icst_desc.params = &icst525_ap_sys_params;
ctype = ICST_INTEGRATOR_AP_SYS;
} else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-pci")) {
icst_desc.params = &icst525_ap_pci_params;
ctype = ICST_INTEGRATOR_AP_PCI;
} 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;
}
/* 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, ctype);
if (IS_ERR(regclk)) {
pr_err("error setting up syscon ICST clock %s\n", name);
return;
}
of_clk_add_provider(np, of_clk_src_simple_get, regclk);
pr_debug("registered syscon ICST clock %s\n", name);
}
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_integratorap_sys_clk,
"arm,syscon-icst525-integratorap-sys", of_syscon_icst_setup);
CLK_OF_DECLARE(arm_syscon_integratorap_pci_clk,
"arm,syscon-icst525-integratorap-pci", 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
