clk: ux500: Add support for sysctrl clocks

The abx500 sysctrl clocks are using the ab8500 sysctrl driver to
modify the clock hardware. Sysctrl clocks are represented by a
ab8500 sysctrl register and with a corresponding bitmask.

The sysctrl clocks are slow path clocks, which means clk_prepare
and clk_unprepare will be used to gate|ungate these clocks.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

diff --git a/drivers/clk/ux500/Makefile b/drivers/clk/ux500/Makefile
index bcc0c11..c6a806e 100644 (file)
--- a/drivers/clk/ux500/Makefile
+++ b/drivers/clk/ux500/Makefile
@@ -5,6 +5,7 @@
 # Clock types
 obj-y += clk-prcc.o
 obj-y += clk-prcmu.o
+obj-y += clk-sysctrl.o
 
 # Clock definitions
 obj-y += u8500_clk.o

diff --git a/drivers/clk/ux500/clk-sysctrl.c b/drivers/clk/ux500/clk-sysctrl.c
new file mode 100644 (file)
index 0000000..bc7e9bd
--- /dev/null
+++ b/drivers/clk/ux500/clk-sysctrl.c
@@ -0,0 +1,221 @@
+/*
+ * Sysctrl clock implementation for ux500 platform.
+ *
+ * Copyright (C) 2013 ST-Ericsson SA
+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/mfd/abx500/ab8500-sysctrl.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include "clk.h"
+
+#define SYSCTRL_MAX_NUM_PARENTS 4
+
+#define to_clk_sysctrl(_hw) container_of(_hw, struct clk_sysctrl, hw)
+
+struct clk_sysctrl {
+       struct clk_hw hw;
+       struct device *dev;
+       u8 parent_index;
+       u16 reg_sel[SYSCTRL_MAX_NUM_PARENTS];
+       u8 reg_mask[SYSCTRL_MAX_NUM_PARENTS];
+       u8 reg_bits[SYSCTRL_MAX_NUM_PARENTS];
+       unsigned long rate;
+       unsigned long enable_delay_us;
+};
+
+/* Sysctrl clock operations. */
+
+static int clk_sysctrl_prepare(struct clk_hw *hw)
+{
+       int ret;
+       struct clk_sysctrl *clk = to_clk_sysctrl(hw);
+
+       ret = ab8500_sysctrl_write(clk->reg_sel[0], clk->reg_mask[0],
+                               clk->reg_bits[0]);
+
+       if (!ret && clk->enable_delay_us)
+               usleep_range(clk->enable_delay_us, clk->enable_delay_us);
+
+       return ret;
+}
+
+static void clk_sysctrl_unprepare(struct clk_hw *hw)
+{
+       struct clk_sysctrl *clk = to_clk_sysctrl(hw);
+       if (ab8500_sysctrl_clear(clk->reg_sel[0], clk->reg_mask[0]))
+               dev_err(clk->dev, "clk_sysctrl: %s fail to clear %s.\n",
+                       __func__, __clk_get_name(hw->clk));
+}
+
+static unsigned long clk_sysctrl_recalc_rate(struct clk_hw *hw,
+                                       unsigned long parent_rate)
+{
+       struct clk_sysctrl *clk = to_clk_sysctrl(hw);
+       return clk->rate;
+}
+
+static int clk_sysctrl_set_parent(struct clk_hw *hw, u8 index)
+{
+       struct clk_sysctrl *clk = to_clk_sysctrl(hw);
+       u8 old_index = clk->parent_index;
+       int ret = 0;
+
+       if (clk->reg_sel[old_index]) {
+               ret = ab8500_sysctrl_clear(clk->reg_sel[old_index],
+                                       clk->reg_mask[old_index]);
+               if (ret)
+                       return ret;
+       }
+
+       if (clk->reg_sel[index]) {
+               ret = ab8500_sysctrl_write(clk->reg_sel[index],
+                                       clk->reg_mask[index],
+                                       clk->reg_bits[index]);
+               if (ret) {
+                       if (clk->reg_sel[old_index])
+                               ab8500_sysctrl_write(clk->reg_sel[old_index],
+                                               clk->reg_mask[old_index],
+                                               clk->reg_bits[old_index]);
+                       return ret;
+               }
+       }
+       clk->parent_index = index;
+
+       return ret;
+}
+
+static u8 clk_sysctrl_get_parent(struct clk_hw *hw)
+{
+       struct clk_sysctrl *clk = to_clk_sysctrl(hw);
+       return clk->parent_index;
+}
+
+static struct clk_ops clk_sysctrl_gate_ops = {
+       .prepare = clk_sysctrl_prepare,
+       .unprepare = clk_sysctrl_unprepare,
+};
+
+static struct clk_ops clk_sysctrl_gate_fixed_rate_ops = {
+       .prepare = clk_sysctrl_prepare,
+       .unprepare = clk_sysctrl_unprepare,
+       .recalc_rate = clk_sysctrl_recalc_rate,
+};
+
+static struct clk_ops clk_sysctrl_set_parent_ops = {
+       .set_parent = clk_sysctrl_set_parent,
+       .get_parent = clk_sysctrl_get_parent,
+};
+
+static struct clk *clk_reg_sysctrl(struct device *dev,
+                               const char *name,
+                               const char **parent_names,
+                               u8 num_parents,
+                               u16 *reg_sel,
+                               u8 *reg_mask,
+                               u8 *reg_bits,
+                               unsigned long rate,
+                               unsigned long enable_delay_us,
+                               unsigned long flags,
+                               struct clk_ops *clk_sysctrl_ops)
+{
+       struct clk_sysctrl *clk;
+       struct clk_init_data clk_sysctrl_init;
+       struct clk *clk_reg;
+       int i;
+
+       if (!dev)
+               return ERR_PTR(-EINVAL);
+
+       if (!name || (num_parents > SYSCTRL_MAX_NUM_PARENTS)) {
+               dev_err(dev, "clk_sysctrl: invalid arguments passed\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       clk = devm_kzalloc(dev, sizeof(struct clk_sysctrl), GFP_KERNEL);
+       if (!clk) {
+               dev_err(dev, "clk_sysctrl: could not allocate clk\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       for (i = 0; i < num_parents; i++) {
+               clk->reg_sel[i] = reg_sel[i];
+               clk->reg_bits[i] = reg_bits[i];
+               clk->reg_mask[i] = reg_mask[i];
+       }
+
+       clk->parent_index = 0;
+       clk->rate = rate;
+       clk->enable_delay_us = enable_delay_us;
+       clk->dev = dev;
+
+       clk_sysctrl_init.name = name;
+       clk_sysctrl_init.ops = clk_sysctrl_ops;
+       clk_sysctrl_init.flags = flags;
+       clk_sysctrl_init.parent_names = parent_names;
+       clk_sysctrl_init.num_parents = num_parents;
+       clk->hw.init = &clk_sysctrl_init;
+
+       clk_reg = devm_clk_register(clk->dev, &clk->hw);
+       if (IS_ERR(clk_reg))
+               dev_err(dev, "clk_sysctrl: clk_register failed\n");
+
+       return clk_reg;
+}
+
+struct clk *clk_reg_sysctrl_gate(struct device *dev,
+                               const char *name,
+                               const char *parent_name,
+                               u16 reg_sel,
+                               u8 reg_mask,
+                               u8 reg_bits,
+                               unsigned long enable_delay_us,
+                               unsigned long flags)
+{
+       const char **parent_names = (parent_name ? &parent_name : NULL);
+       u8 num_parents = (parent_name ? 1 : 0);
+
+       return clk_reg_sysctrl(dev, name, parent_names, num_parents,
+                       &reg_sel, &reg_mask, &reg_bits, 0, enable_delay_us,
+                       flags, &clk_sysctrl_gate_ops);
+}
+
+struct clk *clk_reg_sysctrl_gate_fixed_rate(struct device *dev,
+                                       const char *name,
+                                       const char *parent_name,
+                                       u16 reg_sel,
+                                       u8 reg_mask,
+                                       u8 reg_bits,
+                                       unsigned long rate,
+                                       unsigned long enable_delay_us,
+                                       unsigned long flags)
+{
+       const char **parent_names = (parent_name ? &parent_name : NULL);
+       u8 num_parents = (parent_name ? 1 : 0);
+
+       return clk_reg_sysctrl(dev, name, parent_names, num_parents,
+                       &reg_sel, &reg_mask, &reg_bits,
+                       rate, enable_delay_us, flags,
+                       &clk_sysctrl_gate_fixed_rate_ops);
+}
+
+struct clk *clk_reg_sysctrl_set_parent(struct device *dev,
+                               const char *name,
+                               const char **parent_names,
+                               u8 num_parents,
+                               u16 *reg_sel,
+                               u8 *reg_mask,
+                               u8 *reg_bits,
+                               unsigned long flags)
+{
+       return clk_reg_sysctrl(dev, name, parent_names, num_parents,
+                       reg_sel, reg_mask, reg_bits, 0, 0, flags,
+                       &clk_sysctrl_set_parent_ops);
+}

diff --git a/drivers/clk/ux500/clk.h b/drivers/clk/ux500/clk.h
index c3e4491..3d2dfdc 100644 (file)
--- a/drivers/clk/ux500/clk.h
+++ b/drivers/clk/ux500/clk.h
@@ -11,6 +11,7 @@
 #define __UX500_CLK_H
 
 #include <linux/clk.h>
+#include <linux/device.h>
 
 struct clk *clk_reg_prcc_pclk(const char *name,
                              const char *parent_name,
@@ -57,4 +58,32 @@ struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
                                            unsigned long rate,
                                            unsigned long flags);
 
+struct clk *clk_reg_sysctrl_gate(struct device *dev,
+                                const char *name,
+                                const char *parent_name,
+                                u16 reg_sel,
+                                u8 reg_mask,
+                                u8 reg_bits,
+                                unsigned long enable_delay_us,
+                                unsigned long flags);
+
+struct clk *clk_reg_sysctrl_gate_fixed_rate(struct device *dev,
+                                           const char *name,
+                                           const char *parent_name,
+                                           u16 reg_sel,
+                                           u8 reg_mask,
+                                           u8 reg_bits,
+                                           unsigned long rate,
+                                           unsigned long enable_delay_us,
+                                           unsigned long flags);
+
+struct clk *clk_reg_sysctrl_set_parent(struct device *dev,
+                                      const char *name,
+                                      const char **parent_names,
+                                      u8 num_parents,
+                                      u16 *reg_sel,
+                                      u8 *reg_mask,
+                                      u8 *reg_bits,
+                                      unsigned long flags);
+
 #endif /* __UX500_CLK_H */