--- /dev/null
+/*
+ * clk-flexgen.c
+ *
+ * Copyright (C) ST-Microelectronics SA 2013
+ * Author: Maxime Coquelin <maxime.coquelin@st.com> for ST-Microelectronics.
+ * License terms: GNU General Public License (GPL), version 2 */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+struct flexgen {
+ struct clk_hw hw;
+
+ /* Crossbar */
+ struct clk_mux mux;
+ /* Pre-divisor's gate */
+ struct clk_gate pgate;
+ /* Pre-divisor */
+ struct clk_divider pdiv;
+ /* Final divisor's gate */
+ struct clk_gate fgate;
+ /* Final divisor */
+ struct clk_divider fdiv;
+};
+
+#define to_flexgen(_hw) container_of(_hw, struct flexgen, hw)
+
+static int flexgen_enable(struct clk_hw *hw)
+{
+ struct flexgen *flexgen = to_flexgen(hw);
+ struct clk_hw *pgate_hw = &flexgen->pgate.hw;
+ struct clk_hw *fgate_hw = &flexgen->fgate.hw;
+
+ __clk_hw_set_clk(pgate_hw, hw);
+ __clk_hw_set_clk(fgate_hw, hw);
+
+ clk_gate_ops.enable(pgate_hw);
+
+ clk_gate_ops.enable(fgate_hw);
+
+ pr_debug("%s: flexgen output enabled\n", __clk_get_name(hw->clk));
+ return 0;
+}
+
+static void flexgen_disable(struct clk_hw *hw)
+{
+ struct flexgen *flexgen = to_flexgen(hw);
+ struct clk_hw *fgate_hw = &flexgen->fgate.hw;
+
+ /* disable only the final gate */
+ __clk_hw_set_clk(fgate_hw, hw);
+
+ clk_gate_ops.disable(fgate_hw);
+
+ pr_debug("%s: flexgen output disabled\n", __clk_get_name(hw->clk));
+}
+
+static int flexgen_is_enabled(struct clk_hw *hw)
+{
+ struct flexgen *flexgen = to_flexgen(hw);
+ struct clk_hw *fgate_hw = &flexgen->fgate.hw;
+
+ __clk_hw_set_clk(fgate_hw, hw);
+
+ if (!clk_gate_ops.is_enabled(fgate_hw))
+ return 0;
+
+ return 1;
+}
+
+static u8 flexgen_get_parent(struct clk_hw *hw)
+{
+ struct flexgen *flexgen = to_flexgen(hw);
+ struct clk_hw *mux_hw = &flexgen->mux.hw;
+
+ __clk_hw_set_clk(mux_hw, hw);
+
+ return clk_mux_ops.get_parent(mux_hw);
+}
+
+static int flexgen_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct flexgen *flexgen = to_flexgen(hw);
+ struct clk_hw *mux_hw = &flexgen->mux.hw;
+
+ __clk_hw_set_clk(mux_hw, hw);
+
+ return clk_mux_ops.set_parent(mux_hw, index);
+}
+
+static inline unsigned long
+clk_best_div(unsigned long parent_rate, unsigned long rate)
+{
+ return parent_rate / rate + ((rate > (2*(parent_rate % rate))) ? 0 : 1);
+}
+
+static long flexgen_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ unsigned long div;
+
+ /* Round div according to exact prate and wished rate */
+ div = clk_best_div(*prate, rate);
+
+ if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
+ *prate = rate * div;
+ return rate;
+ }
+
+ return *prate / div;
+}
+
+unsigned long flexgen_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct flexgen *flexgen = to_flexgen(hw);
+ struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
+ struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
+ unsigned long mid_rate;
+
+ __clk_hw_set_clk(pdiv_hw, hw);
+ __clk_hw_set_clk(fdiv_hw, hw);
+
+ mid_rate = clk_divider_ops.recalc_rate(pdiv_hw, parent_rate);
+
+ return clk_divider_ops.recalc_rate(fdiv_hw, mid_rate);
+}
+
+static int flexgen_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct flexgen *flexgen = to_flexgen(hw);
+ struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
+ struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
+ unsigned long div = 0;
+ int ret = 0;
+
+ __clk_hw_set_clk(pdiv_hw, hw);
+ __clk_hw_set_clk(fdiv_hw, hw);
+
+ div = clk_best_div(parent_rate, rate);
+
+ /*
+ * pdiv is mainly targeted for low freq results, while fdiv
+ * should be used for div <= 64. The other way round can
+ * lead to 'duty cycle' issues.
+ */
+
+ if (div <= 64) {
+ clk_divider_ops.set_rate(pdiv_hw, parent_rate, parent_rate);
+ ret = clk_divider_ops.set_rate(fdiv_hw, rate, rate * div);
+ } else {
+ clk_divider_ops.set_rate(fdiv_hw, parent_rate, parent_rate);
+ ret = clk_divider_ops.set_rate(pdiv_hw, rate, rate * div);
+ }
+
+ return ret;
+}
+
+static const struct clk_ops flexgen_ops = {
+ .enable = flexgen_enable,
+ .disable = flexgen_disable,
+ .is_enabled = flexgen_is_enabled,
+ .get_parent = flexgen_get_parent,
+ .set_parent = flexgen_set_parent,
+ .round_rate = flexgen_round_rate,
+ .recalc_rate = flexgen_recalc_rate,
+ .set_rate = flexgen_set_rate,
+};
+
+struct clk *clk_register_flexgen(const char *name,
+ const char **parent_names, u8 num_parents,
+ void __iomem *reg, spinlock_t *lock, u32 idx,
+ unsigned long flexgen_flags) {
+ struct flexgen *fgxbar;
+ struct clk *clk;
+ struct clk_init_data init;
+ u32 xbar_shift;
+ void __iomem *xbar_reg, *fdiv_reg;
+
+ fgxbar = kzalloc(sizeof(struct flexgen), GFP_KERNEL);
+ if (!fgxbar)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &flexgen_ops;
+ init.flags = CLK_IS_BASIC | flexgen_flags;
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+
+ xbar_reg = reg + 0x18 + (idx & ~0x3);
+ xbar_shift = (idx % 4) * 0x8;
+ fdiv_reg = reg + 0x164 + idx * 4;
+
+ /* Crossbar element config */
+ fgxbar->mux.lock = lock;
+ fgxbar->mux.mask = BIT(6) - 1;
+ fgxbar->mux.reg = xbar_reg;
+ fgxbar->mux.shift = xbar_shift;
+ fgxbar->mux.table = NULL;
+
+
+ /* Pre-divider's gate config (in xbar register)*/
+ fgxbar->pgate.lock = lock;
+ fgxbar->pgate.reg = xbar_reg;
+ fgxbar->pgate.bit_idx = xbar_shift + 6;
+
+ /* Pre-divider config */
+ fgxbar->pdiv.lock = lock;
+ fgxbar->pdiv.reg = reg + 0x58 + idx * 4;
+ fgxbar->pdiv.width = 10;
+
+ /* Final divider's gate config */
+ fgxbar->fgate.lock = lock;
+ fgxbar->fgate.reg = fdiv_reg;
+ fgxbar->fgate.bit_idx = 6;
+
+ /* Final divider config */
+ fgxbar->fdiv.lock = lock;
+ fgxbar->fdiv.reg = fdiv_reg;
+ fgxbar->fdiv.width = 6;
+
+ fgxbar->hw.init = &init;
+
+ clk = clk_register(NULL, &fgxbar->hw);
+ if (IS_ERR(clk))
+ kfree(fgxbar);
+ else
+ pr_debug("%s: parent %s rate %u\n",
+ __clk_get_name(clk),
+ __clk_get_name(clk_get_parent(clk)),
+ (unsigned int)clk_get_rate(clk));
+ return clk;
+}
+
+static const char ** __init flexgen_get_parents(struct device_node *np,
+ int *num_parents)
+{
+ const char **parents;
+ int nparents, i;
+
+ nparents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+ if (WARN_ON(nparents <= 0))
+ return NULL;
+
+ parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);
+ if (!parents)
+ return NULL;
+
+ for (i = 0; i < nparents; i++)
+ parents[i] = of_clk_get_parent_name(np, i);
+
+ *num_parents = nparents;
+ return parents;
+}
+
+void __init st_of_flexgen_setup(struct device_node *np)
+{
+ struct device_node *pnode;
+ void __iomem *reg;
+ struct clk_onecell_data *clk_data;
+ const char **parents;
+ int num_parents, i;
+ spinlock_t *rlock = NULL;
+ unsigned long flex_flags = 0;
+
+ pnode = of_get_parent(np);
+ if (!pnode)
+ return;
+
+ reg = of_iomap(pnode, 0);
+ if (!reg)
+ return;
+
+ parents = flexgen_get_parents(np, &num_parents);
+ if (!parents)
+ return;
+
+ clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+ if (!clk_data)
+ goto err;
+
+ clk_data->clk_num = of_property_count_strings(np ,
+ "clock-output-names");
+ if (clk_data->clk_num <= 0) {
+ pr_err("%s: Failed to get number of output clocks (%d)",
+ __func__, clk_data->clk_num);
+ goto err;
+ }
+
+ clk_data->clks = kcalloc(clk_data->clk_num, sizeof(struct clk *),
+ GFP_KERNEL);
+ if (!clk_data->clks)
+ goto err;
+
+ rlock = kzalloc(sizeof(spinlock_t), GFP_KERNEL);
+ if (!rlock)
+ goto err;
+
+ for (i = 0; i < clk_data->clk_num; i++) {
+ struct clk *clk;
+ const char *clk_name;
+
+ if (of_property_read_string_index(np, "clock-output-names",
+ i, &clk_name)) {
+ break;
+ }
+
+ /*
+ * If we read an empty clock name then the output is unused
+ */
+ if (*clk_name == '\0')
+ continue;
+
+ clk = clk_register_flexgen(clk_name, parents, num_parents,
+ reg, rlock, i, flex_flags);
+
+ if (IS_ERR(clk))
+ goto err;
+
+ clk_data->clks[i] = clk;
+ }
+
+ kfree(parents);
+ of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
+
+ return;
+
+err:
+ if (clk_data)
+ kfree(clk_data->clks);
+ kfree(clk_data);
+ kfree(parents);
+ kfree(rlock);
+}
+CLK_OF_DECLARE(flexgen, "st,flexgen", st_of_flexgen_setup);
Code Review / kvmfornfv.git / blobdiff