[PATCH 1/6] clk: stm32f4: Add LSI & LSE clocks
From: gabriel.fernandez
Date: Fri Sep 30 2016 - 10:26:59 EST
From: Gabriel Fernandez <gabriel.fernandez@xxxxxx>
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@xxxxxx>
---
drivers/clk/clk-stm32f4.c | 146 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 142 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
index 02d6810..f57e73c 100644
--- a/drivers/clk/clk-stm32f4.c
+++ b/drivers/clk/clk-stm32f4.c
@@ -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;
@@ -39,6 +45,14 @@ struct stm32f4_gate_data {
const char *parent_name;
unsigned long flags;
};
+struct stm32f4_rgate_data {
+ u8 offset;
+ u8 bit_idx;
+ u8 bit_rdy_idx;
+ const char *name;
+ const char *parent_name;
+ unsigned long flags;
+};
static const struct stm32f4_gate_data stm32f4_gates[] __initconst = {
{ STM32F4_RCC_AHB1ENR, 0, "gpioa", "ahb_div" },
@@ -120,13 +134,13 @@ 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
+#define MAX_CLKS (71 + END_PRIMARY_CLK + 1)
-enum { SYSTICK, FCLK };
/*
* This bitmask tells us which bit offsets (0..192) on STM32F4[23]xxx
@@ -259,7 +273,7 @@ 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 +290,7 @@ 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);
}
@@ -292,8 +306,110 @@ stm32f4_rcc_lookup_clk(struct of_phandle_args *clkspec, void *data)
return clks[i];
}
+static struct regmap *pdrm;
+
+static inline void disable_power_domain_write_protection(void)
+{
+ regmap_update_bits(pdrm, 0x00, (1 << 8), (1 << 8));
+}
+
+static inline void enable_power_domain_write_protection(void)
+{
+ regmap_update_bits(pdrm, 0x00, (1 << 8), (0 << 8));
+}
+
+struct stm32_rgate {
+ struct clk_hw hw;
+ struct clk_gate gate;
+ u8 bit_rdy_idx;
+};
+
+#define RTC_TIMEOUT 1000000
+
+#define to_rgclk(_hw) container_of(_hw, struct stm32_rgate, hw)
+
+static int rgclk_enable(struct clk_hw *hw)
+{
+ struct stm32_rgate *rgate = to_rgclk(hw);
+ struct clk_hw *gate_hw = &rgate->gate.hw;
+ struct clk_gate *gate = to_clk_gate(gate_hw);
+ u32 reg;
+ int ret;
+
+ __clk_hw_set_clk(gate_hw, hw);
+
+ disable_power_domain_write_protection();
+
+ clk_gate_ops.enable(gate_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 | CLK_IS_BASIC;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ rgate->hw.init = &init;
+ rgate->bit_rdy_idx = bit_rdy_idx;
+
+ rgate->gate.lock = lock;
+ rgate->gate.reg = reg;
+ rgate->gate.bit_idx = bit_idx;
+
+ hw = &rgate->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" };
+const char *rtc_parents[4] = {
+ "no-clock", "lse", "lsi", "hse-rtc"
+};
+
static const struct clk_div_table ahb_div_table[] = {
{ 0x0, 1 }, { 0x1, 1 }, { 0x2, 1 }, { 0x3, 1 },
{ 0x4, 1 }, { 0x5, 1 }, { 0x6, 1 }, { 0x7, 1 },
@@ -319,6 +435,12 @@ static void __init stm32f4_rcc_init(struct device_node *np)
return;
}
+ pdrm = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+ if (IS_ERR(pdrm)) {
+ pr_err("%s: Unable to get syscfg\n", __func__);
+ goto fail;
+ }
+
hse_clk = of_clk_get_parent_name(np, 0);
clk_register_fixed_rate_with_accuracy(NULL, "hsi", NULL, 0,
@@ -371,6 +493,22 @@ 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:
--
1.9.1