linux/drivers/clk/keystone/gate.c
Ivan Khoronzhuk a65e0c6a7f clk: keystone: gate: fix clk_init_data initialization
The clk_init_data struct is allocated in the stack. All members of
this struct should be initialized before using otherwise it will
lead to unpredictable situation as it can contain garbage.

Ultimately the clk->flag field contains garbage. In my case it leads
that flag CLK_IGNORE_UNUSED is set for most of clocks. As result a
bunch of unused clocks cannot be disabled.

So initialize flags in this structure too.

Cc: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
2014-02-10 15:17:43 -05:00

270 lines
6.7 KiB
C

/*
* Clock driver for Keystone 2 based devices
*
* Copyright (C) 2013 Texas Instruments.
* Murali Karicheri <m-karicheri2@ti.com>
* Santosh Shilimkar <santosh.shilimkar@ti.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.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of.h>
#include <linux/module.h>
/* PSC register offsets */
#define PTCMD 0x120
#define PTSTAT 0x128
#define PDSTAT 0x200
#define PDCTL 0x300
#define MDSTAT 0x800
#define MDCTL 0xa00
/* PSC module states */
#define PSC_STATE_SWRSTDISABLE 0
#define PSC_STATE_SYNCRST 1
#define PSC_STATE_DISABLE 2
#define PSC_STATE_ENABLE 3
#define MDSTAT_STATE_MASK 0x3f
#define MDSTAT_MCKOUT BIT(12)
#define PDSTAT_STATE_MASK 0x1f
#define MDCTL_FORCE BIT(31)
#define MDCTL_LRESET BIT(8)
#define PDCTL_NEXT BIT(0)
/* Maximum timeout to bail out state transition for module */
#define STATE_TRANS_MAX_COUNT 0xffff
static void __iomem *domain_transition_base;
/**
* struct clk_psc_data - PSC data
* @control_base: Base address for a PSC control
* @domain_base: Base address for a PSC domain
* @domain_id: PSC domain id number
*/
struct clk_psc_data {
void __iomem *control_base;
void __iomem *domain_base;
u32 domain_id;
};
/**
* struct clk_psc - PSC clock structure
* @hw: clk_hw for the psc
* @psc_data: PSC driver specific data
* @lock: Spinlock used by the driver
*/
struct clk_psc {
struct clk_hw hw;
struct clk_psc_data *psc_data;
spinlock_t *lock;
};
static DEFINE_SPINLOCK(psc_lock);
#define to_clk_psc(_hw) container_of(_hw, struct clk_psc, hw)
static void psc_config(void __iomem *control_base, void __iomem *domain_base,
u32 next_state, u32 domain_id)
{
u32 ptcmd, pdstat, pdctl, mdstat, mdctl, ptstat;
u32 count = STATE_TRANS_MAX_COUNT;
mdctl = readl(control_base + MDCTL);
mdctl &= ~MDSTAT_STATE_MASK;
mdctl |= next_state;
/* For disable, we always put the module in local reset */
if (next_state == PSC_STATE_DISABLE)
mdctl &= ~MDCTL_LRESET;
writel(mdctl, control_base + MDCTL);
pdstat = readl(domain_base + PDSTAT);
if (!(pdstat & PDSTAT_STATE_MASK)) {
pdctl = readl(domain_base + PDCTL);
pdctl |= PDCTL_NEXT;
writel(pdctl, domain_base + PDCTL);
}
ptcmd = 1 << domain_id;
writel(ptcmd, domain_transition_base + PTCMD);
do {
ptstat = readl(domain_transition_base + PTSTAT);
} while (((ptstat >> domain_id) & 1) && count--);
count = STATE_TRANS_MAX_COUNT;
do {
mdstat = readl(control_base + MDSTAT);
} while (!((mdstat & MDSTAT_STATE_MASK) == next_state) && count--);
}
static int keystone_clk_is_enabled(struct clk_hw *hw)
{
struct clk_psc *psc = to_clk_psc(hw);
struct clk_psc_data *data = psc->psc_data;
u32 mdstat = readl(data->control_base + MDSTAT);
return (mdstat & MDSTAT_MCKOUT) ? 1 : 0;
}
static int keystone_clk_enable(struct clk_hw *hw)
{
struct clk_psc *psc = to_clk_psc(hw);
struct clk_psc_data *data = psc->psc_data;
unsigned long flags = 0;
if (psc->lock)
spin_lock_irqsave(psc->lock, flags);
psc_config(data->control_base, data->domain_base,
PSC_STATE_ENABLE, data->domain_id);
if (psc->lock)
spin_unlock_irqrestore(psc->lock, flags);
return 0;
}
static void keystone_clk_disable(struct clk_hw *hw)
{
struct clk_psc *psc = to_clk_psc(hw);
struct clk_psc_data *data = psc->psc_data;
unsigned long flags = 0;
if (psc->lock)
spin_lock_irqsave(psc->lock, flags);
psc_config(data->control_base, data->domain_base,
PSC_STATE_DISABLE, data->domain_id);
if (psc->lock)
spin_unlock_irqrestore(psc->lock, flags);
}
static const struct clk_ops clk_psc_ops = {
.enable = keystone_clk_enable,
.disable = keystone_clk_disable,
.is_enabled = keystone_clk_is_enabled,
};
/**
* clk_register_psc - register psc clock
* @dev: device that is registering this clock
* @name: name of this clock
* @parent_name: name of clock's parent
* @psc_data: platform data to configure this clock
* @lock: spinlock used by this clock
*/
static struct clk *clk_register_psc(struct device *dev,
const char *name,
const char *parent_name,
struct clk_psc_data *psc_data,
spinlock_t *lock)
{
struct clk_init_data init;
struct clk_psc *psc;
struct clk *clk;
psc = kzalloc(sizeof(*psc), GFP_KERNEL);
if (!psc)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &clk_psc_ops;
init.flags = 0;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
psc->psc_data = psc_data;
psc->lock = lock;
psc->hw.init = &init;
clk = clk_register(NULL, &psc->hw);
if (IS_ERR(clk))
kfree(psc);
return clk;
}
/**
* of_psc_clk_init - initialize psc clock through DT
* @node: device tree node for this clock
* @lock: spinlock used by this clock
*/
static void __init of_psc_clk_init(struct device_node *node, spinlock_t *lock)
{
const char *clk_name = node->name;
const char *parent_name;
struct clk_psc_data *data;
struct clk *clk;
int i;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
pr_err("%s: Out of memory\n", __func__);
return;
}
i = of_property_match_string(node, "reg-names", "control");
data->control_base = of_iomap(node, i);
if (!data->control_base) {
pr_err("%s: control ioremap failed\n", __func__);
goto out;
}
i = of_property_match_string(node, "reg-names", "domain");
data->domain_base = of_iomap(node, i);
if (!data->domain_base) {
pr_err("%s: domain ioremap failed\n", __func__);
goto unmap_ctrl;
}
of_property_read_u32(node, "domain-id", &data->domain_id);
/* Domain transition registers at fixed address space of domain_id 0 */
if (!domain_transition_base && !data->domain_id)
domain_transition_base = data->domain_base;
of_property_read_string(node, "clock-output-names", &clk_name);
parent_name = of_clk_get_parent_name(node, 0);
if (!parent_name) {
pr_err("%s: Parent clock not found\n", __func__);
goto unmap_domain;
}
clk = clk_register_psc(NULL, clk_name, parent_name, data, lock);
if (!IS_ERR(clk)) {
of_clk_add_provider(node, of_clk_src_simple_get, clk);
return;
}
pr_err("%s: error registering clk %s\n", __func__, node->name);
unmap_domain:
iounmap(data->domain_base);
unmap_ctrl:
iounmap(data->control_base);
out:
kfree(data);
return;
}
/**
* of_keystone_psc_clk_init - initialize psc clock through DT
* @node: device tree node for this clock
*/
static void __init of_keystone_psc_clk_init(struct device_node *node)
{
of_psc_clk_init(node, &psc_lock);
}
CLK_OF_DECLARE(keystone_gate_clk, "ti,keystone,psc-clock",
of_keystone_psc_clk_init);