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path: root/drivers/media/platform/atmel/atmel-isc-clk.c
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-rw-r--r--drivers/media/platform/atmel/atmel-isc-clk.c311
1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/media/platform/atmel/atmel-isc-clk.c b/drivers/media/platform/atmel/atmel-isc-clk.c
new file mode 100644
index 000000000..2059fe376
--- /dev/null
+++ b/drivers/media/platform/atmel/atmel-isc-clk.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Microchip Image Sensor Controller (ISC) common clock driver setup
+ *
+ * Copyright (C) 2016 Microchip Technology, Inc.
+ *
+ * Author: Songjun Wu
+ * Author: Eugen Hristev <eugen.hristev@microchip.com>
+ *
+ */
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include "atmel-isc-regs.h"
+#include "atmel-isc.h"
+
+static int isc_wait_clk_stable(struct clk_hw *hw)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+ struct regmap *regmap = isc_clk->regmap;
+ unsigned long timeout = jiffies + usecs_to_jiffies(1000);
+ unsigned int status;
+
+ while (time_before(jiffies, timeout)) {
+ regmap_read(regmap, ISC_CLKSR, &status);
+ if (!(status & ISC_CLKSR_SIP))
+ return 0;
+
+ usleep_range(10, 250);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int isc_clk_prepare(struct clk_hw *hw)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+ int ret;
+
+ ret = pm_runtime_resume_and_get(isc_clk->dev);
+ if (ret < 0)
+ return ret;
+
+ return isc_wait_clk_stable(hw);
+}
+
+static void isc_clk_unprepare(struct clk_hw *hw)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+
+ isc_wait_clk_stable(hw);
+
+ pm_runtime_put_sync(isc_clk->dev);
+}
+
+static int isc_clk_enable(struct clk_hw *hw)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+ u32 id = isc_clk->id;
+ struct regmap *regmap = isc_clk->regmap;
+ unsigned long flags;
+ unsigned int status;
+
+ dev_dbg(isc_clk->dev, "ISC CLK: %s, id = %d, div = %d, parent id = %d\n",
+ __func__, id, isc_clk->div, isc_clk->parent_id);
+
+ spin_lock_irqsave(&isc_clk->lock, flags);
+ regmap_update_bits(regmap, ISC_CLKCFG,
+ ISC_CLKCFG_DIV_MASK(id) | ISC_CLKCFG_SEL_MASK(id),
+ (isc_clk->div << ISC_CLKCFG_DIV_SHIFT(id)) |
+ (isc_clk->parent_id << ISC_CLKCFG_SEL_SHIFT(id)));
+
+ regmap_write(regmap, ISC_CLKEN, ISC_CLK(id));
+ spin_unlock_irqrestore(&isc_clk->lock, flags);
+
+ regmap_read(regmap, ISC_CLKSR, &status);
+ if (status & ISC_CLK(id))
+ return 0;
+ else
+ return -EINVAL;
+}
+
+static void isc_clk_disable(struct clk_hw *hw)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+ u32 id = isc_clk->id;
+ unsigned long flags;
+
+ spin_lock_irqsave(&isc_clk->lock, flags);
+ regmap_write(isc_clk->regmap, ISC_CLKDIS, ISC_CLK(id));
+ spin_unlock_irqrestore(&isc_clk->lock, flags);
+}
+
+static int isc_clk_is_enabled(struct clk_hw *hw)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+ u32 status;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(isc_clk->dev);
+ if (ret < 0)
+ return 0;
+
+ regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
+
+ pm_runtime_put_sync(isc_clk->dev);
+
+ return status & ISC_CLK(isc_clk->id) ? 1 : 0;
+}
+
+static unsigned long
+isc_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+
+ return DIV_ROUND_CLOSEST(parent_rate, isc_clk->div + 1);
+}
+
+static int isc_clk_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+ long best_rate = -EINVAL;
+ int best_diff = -1;
+ unsigned int i, div;
+
+ for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+ struct clk_hw *parent;
+ unsigned long parent_rate;
+
+ parent = clk_hw_get_parent_by_index(hw, i);
+ if (!parent)
+ continue;
+
+ parent_rate = clk_hw_get_rate(parent);
+ if (!parent_rate)
+ continue;
+
+ for (div = 1; div < ISC_CLK_MAX_DIV + 2; div++) {
+ unsigned long rate;
+ int diff;
+
+ rate = DIV_ROUND_CLOSEST(parent_rate, div);
+ diff = abs(req->rate - rate);
+
+ if (best_diff < 0 || best_diff > diff) {
+ best_rate = rate;
+ best_diff = diff;
+ req->best_parent_rate = parent_rate;
+ req->best_parent_hw = parent;
+ }
+
+ if (!best_diff || rate < req->rate)
+ break;
+ }
+
+ if (!best_diff)
+ break;
+ }
+
+ dev_dbg(isc_clk->dev,
+ "ISC CLK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
+ __func__, best_rate,
+ __clk_get_name((req->best_parent_hw)->clk),
+ req->best_parent_rate);
+
+ if (best_rate < 0)
+ return best_rate;
+
+ req->rate = best_rate;
+
+ return 0;
+}
+
+static int isc_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+
+ if (index >= clk_hw_get_num_parents(hw))
+ return -EINVAL;
+
+ isc_clk->parent_id = index;
+
+ return 0;
+}
+
+static u8 isc_clk_get_parent(struct clk_hw *hw)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+
+ return isc_clk->parent_id;
+}
+
+static int isc_clk_set_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct isc_clk *isc_clk = to_isc_clk(hw);
+ u32 div;
+
+ if (!rate)
+ return -EINVAL;
+
+ div = DIV_ROUND_CLOSEST(parent_rate, rate);
+ if (div > (ISC_CLK_MAX_DIV + 1) || !div)
+ return -EINVAL;
+
+ isc_clk->div = div - 1;
+
+ return 0;
+}
+
+static const struct clk_ops isc_clk_ops = {
+ .prepare = isc_clk_prepare,
+ .unprepare = isc_clk_unprepare,
+ .enable = isc_clk_enable,
+ .disable = isc_clk_disable,
+ .is_enabled = isc_clk_is_enabled,
+ .recalc_rate = isc_clk_recalc_rate,
+ .determine_rate = isc_clk_determine_rate,
+ .set_parent = isc_clk_set_parent,
+ .get_parent = isc_clk_get_parent,
+ .set_rate = isc_clk_set_rate,
+};
+
+static int isc_clk_register(struct isc_device *isc, unsigned int id)
+{
+ struct regmap *regmap = isc->regmap;
+ struct device_node *np = isc->dev->of_node;
+ struct isc_clk *isc_clk;
+ struct clk_init_data init;
+ const char *clk_name = np->name;
+ const char *parent_names[3];
+ int num_parents;
+
+ if (id == ISC_ISPCK && !isc->ispck_required)
+ return 0;
+
+ num_parents = of_clk_get_parent_count(np);
+ if (num_parents < 1 || num_parents > 3)
+ return -EINVAL;
+
+ if (num_parents > 2 && id == ISC_ISPCK)
+ num_parents = 2;
+
+ of_clk_parent_fill(np, parent_names, num_parents);
+
+ if (id == ISC_MCK)
+ of_property_read_string(np, "clock-output-names", &clk_name);
+ else
+ clk_name = "isc-ispck";
+
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+ init.name = clk_name;
+ init.ops = &isc_clk_ops;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+
+ isc_clk = &isc->isc_clks[id];
+ isc_clk->hw.init = &init;
+ isc_clk->regmap = regmap;
+ isc_clk->id = id;
+ isc_clk->dev = isc->dev;
+ spin_lock_init(&isc_clk->lock);
+
+ isc_clk->clk = clk_register(isc->dev, &isc_clk->hw);
+ if (IS_ERR(isc_clk->clk)) {
+ dev_err(isc->dev, "%s: clock register fail\n", clk_name);
+ return PTR_ERR(isc_clk->clk);
+ } else if (id == ISC_MCK) {
+ of_clk_add_provider(np, of_clk_src_simple_get, isc_clk->clk);
+ }
+
+ return 0;
+}
+
+int isc_clk_init(struct isc_device *isc)
+{
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++)
+ isc->isc_clks[i].clk = ERR_PTR(-EINVAL);
+
+ for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) {
+ ret = isc_clk_register(isc, i);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(isc_clk_init);
+
+void isc_clk_cleanup(struct isc_device *isc)
+{
+ unsigned int i;
+
+ of_clk_del_provider(isc->dev->of_node);
+
+ for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) {
+ struct isc_clk *isc_clk = &isc->isc_clks[i];
+
+ if (!IS_ERR(isc_clk->clk))
+ clk_unregister(isc_clk->clk);
+ }
+}
+EXPORT_SYMBOL_GPL(isc_clk_cleanup);