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clk: stm32f4: Add LSI & LSE clocks 

This patch introduces the support of the LSI & LSE clocks.
The clock drivers needs to disable the power domain write protection
using syscon/regmap to enable these clocks.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
hifive-unleashed-5.1
Gabriel Fernandez 2016-10-21 11:23:28 +02:00 committed by Stephen Boyd
parent 82a8e59e88
commit 861adc44d2
1 changed files with 126 additions and 5 deletions
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131
drivers/clk/clk-stm32f4.c
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@ -19,10 +19,14 @@
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#define STM32F4_RCC_PLLCFGR 0x04
#define STM32F4_RCC_CFGR 0x08
@ -31,6 +35,8 @@
#define STM32F4_RCC_AHB3ENR 0x38
#define STM32F4_RCC_APB1ENR 0x40
#define STM32F4_RCC_APB2ENR 0x44
#define STM32F4_RCC_BDCR 0x70
#define STM32F4_RCC_CSR 0x74
struct stm32f4_gate_data {
u8 offset;
@ -120,13 +126,12 @@ static const struct stm32f4_gate_data stm32f4_gates[] __initconst = {
{ STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div" },
};
enum { SYSTICK, FCLK, CLK_LSI, CLK_LSE, END_PRIMARY_CLK };
/*
* MAX_CLKS is the maximum value in the enumeration below plus the combined
* hweight of stm32f42xx_gate_map (plus one).
*/
#define MAX_CLKS 74
enum { SYSTICK, FCLK };
#define MAX_CLKS (71 + END_PRIMARY_CLK + 1)
/*
* This bitmask tells us which bit offsets (0..192) on STM32F4[23]xxx
@ -140,6 +145,8 @@ static struct clk_hw *clks[MAX_CLKS];
static DEFINE_SPINLOCK(stm32f4_clk_lock);
static void __iomem *base;
static struct regmap *pdrm;
/*
* "Multiplier" device for APBx clocks.
*
@ -259,7 +266,7 @@ static int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary)
u64 table[ARRAY_SIZE(stm32f42xx_gate_map)];
if (primary == 1) {
if (WARN_ON(secondary > FCLK))
if (WARN_ON(secondary >= END_PRIMARY_CLK))
return -EINVAL;
return secondary;
}
@ -276,7 +283,7 @@ static int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary)
table[BIT_ULL_WORD(secondary)] &=
GENMASK_ULL(secondary % BITS_PER_LONG_LONG, 0);
return FCLK + hweight64(table[0]) +
return END_PRIMARY_CLK - 1 + hweight64(table[0]) +
(BIT_ULL_WORD(secondary) >= 1 ? hweight64(table[1]) : 0) +
(BIT_ULL_WORD(secondary) >= 2 ? hweight64(table[2]) : 0);
}
@ -292,6 +299,98 @@ stm32f4_rcc_lookup_clk(struct of_phandle_args *clkspec, void *data)
return clks[i];
}
#define to_rgclk(_rgate) container_of(_rgate, struct stm32_rgate, gate)
static inline void disable_power_domain_write_protection(void)
{
if (pdrm)
regmap_update_bits(pdrm, 0x00, (1 << 8), (1 << 8));
}
static inline void enable_power_domain_write_protection(void)
{
if (pdrm)
regmap_update_bits(pdrm, 0x00, (1 << 8), (0 << 8));
}
struct stm32_rgate {
struct clk_gate gate;
u8 bit_rdy_idx;
};
#define RTC_TIMEOUT 1000000
static int rgclk_enable(struct clk_hw *hw)
{
struct clk_gate *gate = to_clk_gate(hw);
struct stm32_rgate *rgate = to_rgclk(gate);
u32 reg;
int ret;
disable_power_domain_write_protection();
clk_gate_ops.enable(hw);
ret = readl_relaxed_poll_timeout_atomic(gate->reg, reg,
reg & rgate->bit_rdy_idx, 1000, RTC_TIMEOUT);
enable_power_domain_write_protection();
return ret;
}
static void rgclk_disable(struct clk_hw *hw)
{
clk_gate_ops.disable(hw);
}
static int rgclk_is_enabled(struct clk_hw *hw)
{
return clk_gate_ops.is_enabled(hw);
}
static const struct clk_ops rgclk_ops = {
.enable = rgclk_enable,
.disable = rgclk_disable,
.is_enabled = rgclk_is_enabled,
};
static struct clk_hw *clk_register_rgate(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
void __iomem *reg, u8 bit_idx, u8 bit_rdy_idx,
u8 clk_gate_flags, spinlock_t *lock)
{
struct stm32_rgate *rgate;
struct clk_init_data init = { NULL };
struct clk_hw *hw;
int ret;
rgate = kzalloc(sizeof(*rgate), GFP_KERNEL);
if (!rgate)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &rgclk_ops;
init.flags = flags;
init.parent_names = &parent_name;
init.num_parents = 1;
rgate->bit_rdy_idx = bit_rdy_idx;
rgate->gate.lock = lock;
rgate->gate.reg = reg;
rgate->gate.bit_idx = bit_idx;
rgate->gate.hw.init = &init;
hw = &rgate->gate.hw;
ret = clk_hw_register(dev, hw);
if (ret) {
kfree(rgate);
hw = ERR_PTR(ret);
}
return hw;
}
static const char *sys_parents[] __initdata = { "hsi", NULL, "pll" };
static const struct clk_div_table ahb_div_table[] = {
@ -319,6 +418,12 @@ static void __init stm32f4_rcc_init(struct device_node *np)
return;
}
pdrm = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
if (IS_ERR(pdrm)) {
pdrm = NULL;
pr_warn("%s: Unable to get syscfg\n", __func__);
}
hse_clk = of_clk_get_parent_name(np, 0);
clk_register_fixed_rate_with_accuracy(NULL, "hsi", NULL, 0,
@ -371,6 +476,22 @@ static void __init stm32f4_rcc_init(struct device_node *np)
}
}
clks[CLK_LSI] = clk_register_rgate(NULL, "lsi", "clk-lsi", 0,
base + STM32F4_RCC_CSR, 0, 2, 0, &stm32f4_clk_lock);
if (IS_ERR(clks[CLK_LSI])) {
pr_err("Unable to register lsi clock\n");
goto fail;
}
clks[CLK_LSE] = clk_register_rgate(NULL, "lse", "clk-lse", 0,
base + STM32F4_RCC_BDCR, 0, 2, 0, &stm32f4_clk_lock);
if (IS_ERR(clks[CLK_LSE])) {
pr_err("Unable to register lse clock\n");
goto fail;
}
of_clk_add_hw_provider(np, stm32f4_rcc_lookup_clk, NULL);
return;
fail: