OpenCloudOS-Kernel/drivers/clk/sunxi/clk-mod0.c

285 lines
6.6 KiB
C

/*
* Copyright 2013 Emilio López
*
* Emilio López <emilio@elopez.com.ar>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/of_address.h>
#include "clk-factors.h"
/**
* sun4i_get_mod0_factors() - calculates m, n factors for MOD0-style clocks
* MOD0 rate is calculated as follows
* rate = (parent_rate >> p) / (m + 1);
*/
static void sun4i_a10_get_mod0_factors(u32 *freq, u32 parent_rate,
u8 *n, u8 *k, u8 *m, u8 *p)
{
u8 div, calcm, calcp;
/* These clocks can only divide, so we will never be able to achieve
* frequencies higher than the parent frequency */
if (*freq > parent_rate)
*freq = parent_rate;
div = DIV_ROUND_UP(parent_rate, *freq);
if (div < 16)
calcp = 0;
else if (div / 2 < 16)
calcp = 1;
else if (div / 4 < 16)
calcp = 2;
else
calcp = 3;
calcm = DIV_ROUND_UP(div, 1 << calcp);
*freq = (parent_rate >> calcp) / calcm;
/* we were called to round the frequency, we can now return */
if (n == NULL)
return;
*m = calcm - 1;
*p = calcp;
}
/* user manual says "n" but it's really "p" */
static struct clk_factors_config sun4i_a10_mod0_config = {
.mshift = 0,
.mwidth = 4,
.pshift = 16,
.pwidth = 2,
};
static const struct factors_data sun4i_a10_mod0_data __initconst = {
.enable = 31,
.mux = 24,
.muxmask = BIT(1) | BIT(0),
.table = &sun4i_a10_mod0_config,
.getter = sun4i_a10_get_mod0_factors,
};
static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
static void __init sun4i_a10_mod0_setup(struct device_node *node)
{
sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
}
CLK_OF_DECLARE(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk", sun4i_a10_mod0_setup);
static DEFINE_SPINLOCK(sun5i_a13_mbus_lock);
static void __init sun5i_a13_mbus_setup(struct device_node *node)
{
struct clk *mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun5i_a13_mbus_lock);
/* The MBUS clocks needs to be always enabled */
__clk_get(mbus);
clk_prepare_enable(mbus);
}
CLK_OF_DECLARE(sun5i_a13_mbus, "allwinner,sun5i-a13-mbus-clk", sun5i_a13_mbus_setup);
struct mmc_phase_data {
u8 offset;
};
struct mmc_phase {
struct clk_hw hw;
void __iomem *reg;
struct mmc_phase_data *data;
spinlock_t *lock;
};
#define to_mmc_phase(_hw) container_of(_hw, struct mmc_phase, hw)
static int mmc_get_phase(struct clk_hw *hw)
{
struct clk *mmc, *mmc_parent, *clk = hw->clk;
struct mmc_phase *phase = to_mmc_phase(hw);
unsigned int mmc_rate, mmc_parent_rate;
u16 step, mmc_div;
u32 value;
u8 delay;
value = readl(phase->reg);
delay = (value >> phase->data->offset) & 0x3;
if (!delay)
return 180;
/* Get the main MMC clock */
mmc = clk_get_parent(clk);
if (!mmc)
return -EINVAL;
/* And its rate */
mmc_rate = clk_get_rate(mmc);
if (!mmc_rate)
return -EINVAL;
/* Now, get the MMC parent (most likely some PLL) */
mmc_parent = clk_get_parent(mmc);
if (!mmc_parent)
return -EINVAL;
/* And its rate */
mmc_parent_rate = clk_get_rate(mmc_parent);
if (!mmc_parent_rate)
return -EINVAL;
/* Get MMC clock divider */
mmc_div = mmc_parent_rate / mmc_rate;
step = DIV_ROUND_CLOSEST(360, mmc_div);
return delay * step;
}
static int mmc_set_phase(struct clk_hw *hw, int degrees)
{
struct clk *mmc, *mmc_parent, *clk = hw->clk;
struct mmc_phase *phase = to_mmc_phase(hw);
unsigned int mmc_rate, mmc_parent_rate;
unsigned long flags;
u32 value;
u8 delay;
/* Get the main MMC clock */
mmc = clk_get_parent(clk);
if (!mmc)
return -EINVAL;
/* And its rate */
mmc_rate = clk_get_rate(mmc);
if (!mmc_rate)
return -EINVAL;
/* Now, get the MMC parent (most likely some PLL) */
mmc_parent = clk_get_parent(mmc);
if (!mmc_parent)
return -EINVAL;
/* And its rate */
mmc_parent_rate = clk_get_rate(mmc_parent);
if (!mmc_parent_rate)
return -EINVAL;
if (degrees != 180) {
u16 step, mmc_div;
/* Get MMC clock divider */
mmc_div = mmc_parent_rate / mmc_rate;
/*
* We can only outphase the clocks by multiple of the
* PLL's period.
*
* Since the MMC clock in only a divider, and the
* formula to get the outphasing in degrees is deg =
* 360 * delta / period
*
* If we simplify this formula, we can see that the
* only thing that we're concerned about is the number
* of period we want to outphase our clock from, and
* the divider set by the MMC clock.
*/
step = DIV_ROUND_CLOSEST(360, mmc_div);
delay = DIV_ROUND_CLOSEST(degrees, step);
} else {
delay = 0;
}
spin_lock_irqsave(phase->lock, flags);
value = readl(phase->reg);
value &= ~GENMASK(phase->data->offset + 3, phase->data->offset);
value |= delay << phase->data->offset;
writel(value, phase->reg);
spin_unlock_irqrestore(phase->lock, flags);
return 0;
}
static const struct clk_ops mmc_clk_ops = {
.get_phase = mmc_get_phase,
.set_phase = mmc_set_phase,
};
static void __init sun4i_a10_mmc_phase_setup(struct device_node *node,
struct mmc_phase_data *data)
{
const char *parent_names[1] = { of_clk_get_parent_name(node, 0) };
struct clk_init_data init = {
.num_parents = 1,
.parent_names = parent_names,
.ops = &mmc_clk_ops,
};
struct mmc_phase *phase;
struct clk *clk;
phase = kmalloc(sizeof(*phase), GFP_KERNEL);
if (!phase)
return;
phase->hw.init = &init;
phase->reg = of_iomap(node, 0);
if (!phase->reg)
goto err_free;
phase->data = data;
phase->lock = &sun4i_a10_mod0_lock;
if (of_property_read_string(node, "clock-output-names", &init.name))
init.name = node->name;
clk = clk_register(NULL, &phase->hw);
if (IS_ERR(clk))
goto err_unmap;
of_clk_add_provider(node, of_clk_src_simple_get, clk);
return;
err_unmap:
iounmap(phase->reg);
err_free:
kfree(phase);
}
static struct mmc_phase_data mmc_output_clk = {
.offset = 8,
};
static struct mmc_phase_data mmc_sample_clk = {
.offset = 20,
};
static void __init sun4i_a10_mmc_output_setup(struct device_node *node)
{
sun4i_a10_mmc_phase_setup(node, &mmc_output_clk);
}
CLK_OF_DECLARE(sun4i_a10_mmc_output, "allwinner,sun4i-a10-mmc-output-clk", sun4i_a10_mmc_output_setup);
static void __init sun4i_a10_mmc_sample_setup(struct device_node *node)
{
sun4i_a10_mmc_phase_setup(node, &mmc_sample_clk);
}
CLK_OF_DECLARE(sun4i_a10_mmc_sample, "allwinner,sun4i-a10-mmc-sample-clk", sun4i_a10_mmc_sample_setup);