linux/drivers/clk/at91/clk-usb.c
Boris BREZILLON c84a61d872 clk: at91: add PMC usb clock
This patch adds new at91 usb clock implementation using common clk framework.
This clock is used to clock usb ports (ohci, ehci and udc).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2013-12-02 15:31:25 +01:00

399 lines
9.4 KiB
C

/*
* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include "pmc.h"
#define USB_SOURCE_MAX 2
#define SAM9X5_USB_DIV_SHIFT 8
#define SAM9X5_USB_MAX_DIV 0xf
#define RM9200_USB_DIV_SHIFT 28
#define RM9200_USB_DIV_TAB_SIZE 4
struct at91sam9x5_clk_usb {
struct clk_hw hw;
struct at91_pmc *pmc;
};
#define to_at91sam9x5_clk_usb(hw) \
container_of(hw, struct at91sam9x5_clk_usb, hw)
struct at91rm9200_clk_usb {
struct clk_hw hw;
struct at91_pmc *pmc;
u32 divisors[4];
};
#define to_at91rm9200_clk_usb(hw) \
container_of(hw, struct at91rm9200_clk_usb, hw)
static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
u32 tmp;
u8 usbdiv;
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
tmp = pmc_read(pmc, AT91_PMC_USB);
usbdiv = (tmp & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
return parent_rate / (usbdiv + 1);
}
static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
unsigned long div;
unsigned long bestrate;
unsigned long tmp;
if (rate >= *parent_rate)
return *parent_rate;
div = *parent_rate / rate;
if (div >= SAM9X5_USB_MAX_DIV)
return *parent_rate / (SAM9X5_USB_MAX_DIV + 1);
bestrate = *parent_rate / div;
tmp = *parent_rate / (div + 1);
if (bestrate - rate > rate - tmp)
bestrate = tmp;
return bestrate;
}
static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
{
u32 tmp;
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
if (index > 1)
return -EINVAL;
tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS;
if (index)
tmp |= AT91_PMC_USBS;
pmc_write(pmc, AT91_PMC_USB, tmp);
return 0;
}
static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
{
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
return pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS;
}
static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
u32 tmp;
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
unsigned long div = parent_rate / rate;
if (parent_rate % rate || div < 1 || div >= SAM9X5_USB_MAX_DIV)
return -EINVAL;
tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;
tmp |= (div - 1) << SAM9X5_USB_DIV_SHIFT;
pmc_write(pmc, AT91_PMC_USB, tmp);
return 0;
}
static const struct clk_ops at91sam9x5_usb_ops = {
.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
.round_rate = at91sam9x5_clk_usb_round_rate,
.get_parent = at91sam9x5_clk_usb_get_parent,
.set_parent = at91sam9x5_clk_usb_set_parent,
.set_rate = at91sam9x5_clk_usb_set_rate,
};
static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
{
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
pmc_write(pmc, AT91_PMC_USB,
pmc_read(pmc, AT91_PMC_USB) | AT91_PMC_USBS);
return 0;
}
static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
{
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
pmc_write(pmc, AT91_PMC_USB,
pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS);
}
static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
{
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
return !!(pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS);
}
static const struct clk_ops at91sam9n12_usb_ops = {
.enable = at91sam9n12_clk_usb_enable,
.disable = at91sam9n12_clk_usb_disable,
.is_enabled = at91sam9n12_clk_usb_is_enabled,
.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
.round_rate = at91sam9x5_clk_usb_round_rate,
.set_rate = at91sam9x5_clk_usb_set_rate,
};
static struct clk * __init
at91sam9x5_clk_register_usb(struct at91_pmc *pmc, const char *name,
const char **parent_names, u8 num_parents)
{
struct at91sam9x5_clk_usb *usb;
struct clk *clk = NULL;
struct clk_init_data init;
usb = kzalloc(sizeof(*usb), GFP_KERNEL);
if (!usb)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &at91sam9x5_usb_ops;
init.parent_names = parent_names;
init.num_parents = num_parents;
init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
usb->hw.init = &init;
usb->pmc = pmc;
clk = clk_register(NULL, &usb->hw);
if (IS_ERR(clk))
kfree(usb);
return clk;
}
static struct clk * __init
at91sam9n12_clk_register_usb(struct at91_pmc *pmc, const char *name,
const char *parent_name)
{
struct at91sam9x5_clk_usb *usb;
struct clk *clk = NULL;
struct clk_init_data init;
usb = kzalloc(sizeof(*usb), GFP_KERNEL);
if (!usb)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &at91sam9n12_usb_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = CLK_SET_RATE_GATE;
usb->hw.init = &init;
usb->pmc = pmc;
clk = clk_register(NULL, &usb->hw);
if (IS_ERR(clk))
kfree(usb);
return clk;
}
static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
u32 tmp;
u8 usbdiv;
tmp = pmc_read(pmc, AT91_CKGR_PLLBR);
usbdiv = (tmp & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
if (usb->divisors[usbdiv])
return parent_rate / usb->divisors[usbdiv];
return 0;
}
static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
unsigned long bestrate = 0;
int bestdiff = -1;
unsigned long tmprate;
int tmpdiff;
int i = 0;
for (i = 0; i < 4; i++) {
if (!usb->divisors[i])
continue;
tmprate = *parent_rate / usb->divisors[i];
if (tmprate < rate)
tmpdiff = rate - tmprate;
else
tmpdiff = tmprate - rate;
if (bestdiff < 0 || bestdiff > tmpdiff) {
bestrate = tmprate;
bestdiff = tmpdiff;
}
if (!bestdiff)
break;
}
return bestrate;
}
static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
u32 tmp;
int i;
struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
unsigned long div = parent_rate / rate;
if (parent_rate % rate)
return -EINVAL;
for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
if (usb->divisors[i] == div) {
tmp = pmc_read(pmc, AT91_CKGR_PLLBR) &
~AT91_PMC_USBDIV;
tmp |= i << RM9200_USB_DIV_SHIFT;
pmc_write(pmc, AT91_CKGR_PLLBR, tmp);
return 0;
}
}
return -EINVAL;
}
static const struct clk_ops at91rm9200_usb_ops = {
.recalc_rate = at91rm9200_clk_usb_recalc_rate,
.round_rate = at91rm9200_clk_usb_round_rate,
.set_rate = at91rm9200_clk_usb_set_rate,
};
static struct clk * __init
at91rm9200_clk_register_usb(struct at91_pmc *pmc, const char *name,
const char *parent_name, const u32 *divisors)
{
struct at91rm9200_clk_usb *usb;
struct clk *clk = NULL;
struct clk_init_data init;
usb = kzalloc(sizeof(*usb), GFP_KERNEL);
if (!usb)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &at91rm9200_usb_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = 0;
usb->hw.init = &init;
usb->pmc = pmc;
memcpy(usb->divisors, divisors, sizeof(usb->divisors));
clk = clk_register(NULL, &usb->hw);
if (IS_ERR(clk))
kfree(usb);
return clk;
}
void __init of_at91sam9x5_clk_usb_setup(struct device_node *np,
struct at91_pmc *pmc)
{
struct clk *clk;
int i;
int num_parents;
const char *parent_names[USB_SOURCE_MAX];
const char *name = np->name;
num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
if (num_parents <= 0 || num_parents > USB_SOURCE_MAX)
return;
for (i = 0; i < num_parents; i++) {
parent_names[i] = of_clk_get_parent_name(np, i);
if (!parent_names[i])
return;
}
of_property_read_string(np, "clock-output-names", &name);
clk = at91sam9x5_clk_register_usb(pmc, name, parent_names, num_parents);
if (IS_ERR(clk))
return;
of_clk_add_provider(np, of_clk_src_simple_get, clk);
}
void __init of_at91sam9n12_clk_usb_setup(struct device_node *np,
struct at91_pmc *pmc)
{
struct clk *clk;
const char *parent_name;
const char *name = np->name;
parent_name = of_clk_get_parent_name(np, 0);
if (!parent_name)
return;
of_property_read_string(np, "clock-output-names", &name);
clk = at91sam9n12_clk_register_usb(pmc, name, parent_name);
if (IS_ERR(clk))
return;
of_clk_add_provider(np, of_clk_src_simple_get, clk);
}
void __init of_at91rm9200_clk_usb_setup(struct device_node *np,
struct at91_pmc *pmc)
{
struct clk *clk;
const char *parent_name;
const char *name = np->name;
u32 divisors[4] = {0, 0, 0, 0};
parent_name = of_clk_get_parent_name(np, 0);
if (!parent_name)
return;
of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
if (!divisors[0])
return;
of_property_read_string(np, "clock-output-names", &name);
clk = at91rm9200_clk_register_usb(pmc, name, parent_name, divisors);
if (IS_ERR(clk))
return;
of_clk_add_provider(np, of_clk_src_simple_get, clk);
}