kernel-fxtec-pro1x/drivers/clk/pxa/clk-pxa.c
Robert Jarzmik bda0030366 clk: add pxa clocks infrastructure
Add a the common code used by all PXA variants.

This is the first step in the transition from architecture defined
clocks (in arch/arm/mach-pxa) towards clock framework. The goal is to
have the same features (and not all the features) of the existing
clocks, and enable the transition of PXA to device-tree.

All PXA rely on a "CKEN" type clock, which :
 - has a gate (bit in CKEN register)
 - is generated from a PLL, generally divided
 - has an alternate low power clock

Each variant will specialize the CKEN clock :
 - pxa25x have no low power clock
 - pxa27x in low power use always the 13 MHz ring oscillator
 - pxa3xx in low power have specific dividers for each clock

The device-tree provides a list of CLK_* (ex: CLK_USB or CLK_I2C) to get
a handle on the clock. While pxa-clock.h will describe all the clocks of
all the variants, each variant will only use a subset of it.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-09-30 12:31:30 -07:00

97 lines
2.4 KiB
C

/*
* Marvell PXA family clocks
*
* Copyright (C) 2014 Robert Jarzmik
*
* Common clock code for PXA clocks ("CKEN" type clocks + DT)
*
* 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; version 2 of the License.
*
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/of.h>
#include <dt-bindings/clock/pxa-clock.h>
#include "clk-pxa.h"
DEFINE_SPINLOCK(lock);
static struct clk *pxa_clocks[CLK_MAX];
static struct clk_onecell_data onecell_data = {
.clks = pxa_clocks,
.clk_num = CLK_MAX,
};
#define to_pxa_clk(_hw) container_of(_hw, struct pxa_clk_cken, hw)
static unsigned long cken_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct pxa_clk_cken *pclk = to_pxa_clk(hw);
struct clk_fixed_factor *fix;
if (!pclk->is_in_low_power || pclk->is_in_low_power())
fix = &pclk->lp;
else
fix = &pclk->hp;
fix->hw.clk = hw->clk;
return clk_fixed_factor_ops.recalc_rate(&fix->hw, parent_rate);
}
static struct clk_ops cken_rate_ops = {
.recalc_rate = cken_recalc_rate,
};
static u8 cken_get_parent(struct clk_hw *hw)
{
struct pxa_clk_cken *pclk = to_pxa_clk(hw);
if (!pclk->is_in_low_power)
return 0;
return pclk->is_in_low_power() ? 0 : 1;
}
static struct clk_ops cken_mux_ops = {
.get_parent = cken_get_parent,
.set_parent = dummy_clk_set_parent,
};
void __init clkdev_pxa_register(int ckid, const char *con_id,
const char *dev_id, struct clk *clk)
{
if (!IS_ERR(clk) && (ckid != CLK_NONE))
pxa_clocks[ckid] = clk;
if (!IS_ERR(clk))
clk_register_clkdev(clk, con_id, dev_id);
}
int __init clk_pxa_cken_init(struct pxa_clk_cken *clks, int nb_clks)
{
int i;
struct pxa_clk_cken *pclk;
struct clk *clk;
for (i = 0; i < nb_clks; i++) {
pclk = clks + i;
pclk->gate.lock = &lock;
clk = clk_register_composite(NULL, pclk->name,
pclk->parent_names, 2,
&pclk->hw, &cken_mux_ops,
&pclk->hw, &cken_rate_ops,
&pclk->gate.hw, &clk_gate_ops,
pclk->flags);
clkdev_pxa_register(pclk->ckid, pclk->con_id, pclk->dev_id,
clk);
}
return 0;
}
static void __init pxa_dt_clocks_init(struct device_node *np)
{
of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data);
}
CLK_OF_DECLARE(pxa_clks, "marvell,pxa-clocks", pxa_dt_clocks_init);