clk: qcom: Add support for branches/gate clocks
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/qcom/clk-branch.c b/drivers/clk/qcom/clk-branch.c
new file mode 100644
index 0000000..6b4d2bc
--- /dev/null
+++ b/drivers/clk/qcom/clk-branch.c
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/kernel.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+
+#include "clk-branch.h"
+
+static bool clk_branch_in_hwcg_mode(const struct clk_branch *br)
+{
+ u32 val;
+
+ if (!br->hwcg_reg)
+ return 0;
+
+ regmap_read(br->clkr.regmap, br->hwcg_reg, &val);
+
+ return !!(val & BIT(br->hwcg_bit));
+}
+
+static bool clk_branch_check_halt(const struct clk_branch *br, bool enabling)
+{
+ bool invert = (br->halt_check == BRANCH_HALT_ENABLE);
+ u32 val;
+
+ regmap_read(br->clkr.regmap, br->halt_reg, &val);
+
+ val &= BIT(br->halt_bit);
+ if (invert)
+ val = !val;
+
+ return !!val == !enabling;
+}
+
+#define BRANCH_CLK_OFF BIT(31)
+#define BRANCH_NOC_FSM_STATUS_SHIFT 28
+#define BRANCH_NOC_FSM_STATUS_MASK 0x7
+#define BRANCH_NOC_FSM_STATUS_ON (0x2 << BRANCH_NOC_FSM_STATUS_SHIFT)
+
+static bool clk_branch2_check_halt(const struct clk_branch *br, bool enabling)
+{
+ u32 val;
+ u32 mask;
+
+ mask = BRANCH_NOC_FSM_STATUS_MASK << BRANCH_NOC_FSM_STATUS_SHIFT;
+ mask |= BRANCH_CLK_OFF;
+
+ regmap_read(br->clkr.regmap, br->halt_reg, &val);
+
+ if (enabling) {
+ val &= mask;
+ return (val & BRANCH_CLK_OFF) == 0 ||
+ val == BRANCH_NOC_FSM_STATUS_ON;
+ } else {
+ return val & BRANCH_CLK_OFF;
+ }
+}
+
+static int clk_branch_wait(const struct clk_branch *br, bool enabling,
+ bool (check_halt)(const struct clk_branch *, bool))
+{
+ bool voted = br->halt_check & BRANCH_VOTED;
+ const char *name = __clk_get_name(br->clkr.hw.clk);
+
+ /* Skip checking halt bit if the clock is in hardware gated mode */
+ if (clk_branch_in_hwcg_mode(br))
+ return 0;
+
+ if (br->halt_check == BRANCH_HALT_DELAY || (!enabling && voted)) {
+ udelay(10);
+ } else if (br->halt_check == BRANCH_HALT_ENABLE ||
+ br->halt_check == BRANCH_HALT ||
+ (enabling && voted)) {
+ int count = 200;
+
+ while (count-- > 0) {
+ if (check_halt(br, enabling))
+ return 0;
+ udelay(1);
+ }
+ WARN(1, "%s status stuck at 'o%s'", name,
+ enabling ? "ff" : "n");
+ return -EBUSY;
+ }
+ return 0;
+}
+
+static int clk_branch_toggle(struct clk_hw *hw, bool en,
+ bool (check_halt)(const struct clk_branch *, bool))
+{
+ struct clk_branch *br = to_clk_branch(hw);
+ int ret;
+
+ if (en) {
+ ret = clk_enable_regmap(hw);
+ if (ret)
+ return ret;
+ } else {
+ clk_disable_regmap(hw);
+ }
+
+ return clk_branch_wait(br, en, check_halt);
+}
+
+static int clk_branch_enable(struct clk_hw *hw)
+{
+ return clk_branch_toggle(hw, true, clk_branch_check_halt);
+}
+
+static void clk_branch_disable(struct clk_hw *hw)
+{
+ clk_branch_toggle(hw, false, clk_branch_check_halt);
+}
+
+const struct clk_ops clk_branch_ops = {
+ .enable = clk_branch_enable,
+ .disable = clk_branch_disable,
+ .is_enabled = clk_is_enabled_regmap,
+};
+EXPORT_SYMBOL_GPL(clk_branch_ops);
+
+static int clk_branch2_enable(struct clk_hw *hw)
+{
+ return clk_branch_toggle(hw, true, clk_branch2_check_halt);
+}
+
+static void clk_branch2_disable(struct clk_hw *hw)
+{
+ clk_branch_toggle(hw, false, clk_branch2_check_halt);
+}
+
+const struct clk_ops clk_branch2_ops = {
+ .enable = clk_branch2_enable,
+ .disable = clk_branch2_disable,
+ .is_enabled = clk_is_enabled_regmap,
+};
+EXPORT_SYMBOL_GPL(clk_branch2_ops);
+
+const struct clk_ops clk_branch_simple_ops = {
+ .enable = clk_enable_regmap,
+ .disable = clk_disable_regmap,
+ .is_enabled = clk_is_enabled_regmap,
+};
+EXPORT_SYMBOL_GPL(clk_branch_simple_ops);