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authorRobert Jarzmik <robert.jarzmik@free.fr>2014-07-31 00:50:59 +0400
committerMike Turquette <mturquette@linaro.org>2014-09-30 23:31:30 +0400
commitbda003036684b9779fca2b3d457621eaff9bcd0a (patch)
treeab1b69b8d74b6baa63c0dd021fbbf562f36c56e2 /drivers/clk/pxa
parent7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9 (diff)
downloadlinux-bda003036684b9779fca2b3d457621eaff9bcd0a.tar.xz
clk: add pxa clocks infrastructure
Add a the common code used by all PXA variants. This is the first step in the transition from architecture defined clocks (in arch/arm/mach-pxa) towards clock framework. The goal is to have the same features (and not all the features) of the existing clocks, and enable the transition of PXA to device-tree. All PXA rely on a "CKEN" type clock, which : - has a gate (bit in CKEN register) - is generated from a PLL, generally divided - has an alternate low power clock Each variant will specialize the CKEN clock : - pxa25x have no low power clock - pxa27x in low power use always the 13 MHz ring oscillator - pxa3xx in low power have specific dividers for each clock The device-tree provides a list of CLK_* (ex: CLK_USB or CLK_I2C) to get a handle on the clock. While pxa-clock.h will describe all the clocks of all the variants, each variant will only use a subset of it. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/pxa')
-rw-r--r--drivers/clk/pxa/Makefile1
-rw-r--r--drivers/clk/pxa/clk-pxa.c97
-rw-r--r--drivers/clk/pxa/clk-pxa.h107
3 files changed, 205 insertions, 0 deletions
diff --git a/drivers/clk/pxa/Makefile b/drivers/clk/pxa/Makefile
new file mode 100644
index 000000000000..cb2bd8ff53da
--- /dev/null
+++ b/drivers/clk/pxa/Makefile
@@ -0,0 +1 @@
+obj-y += clk-pxa.o
diff --git a/drivers/clk/pxa/clk-pxa.c b/drivers/clk/pxa/clk-pxa.c
new file mode 100644
index 000000000000..ef3c05389c0a
--- /dev/null
+++ b/drivers/clk/pxa/clk-pxa.c
@@ -0,0 +1,97 @@
+/*
+ * Marvell PXA family clocks
+ *
+ * Copyright (C) 2014 Robert Jarzmik
+ *
+ * Common clock code for PXA clocks ("CKEN" type clocks + DT)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ */
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/of.h>
+
+#include <dt-bindings/clock/pxa-clock.h>
+#include "clk-pxa.h"
+
+DEFINE_SPINLOCK(lock);
+
+static struct clk *pxa_clocks[CLK_MAX];
+static struct clk_onecell_data onecell_data = {
+ .clks = pxa_clocks,
+ .clk_num = CLK_MAX,
+};
+
+#define to_pxa_clk(_hw) container_of(_hw, struct pxa_clk_cken, hw)
+
+static unsigned long cken_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct pxa_clk_cken *pclk = to_pxa_clk(hw);
+ struct clk_fixed_factor *fix;
+
+ if (!pclk->is_in_low_power || pclk->is_in_low_power())
+ fix = &pclk->lp;
+ else
+ fix = &pclk->hp;
+ fix->hw.clk = hw->clk;
+ return clk_fixed_factor_ops.recalc_rate(&fix->hw, parent_rate);
+}
+
+static struct clk_ops cken_rate_ops = {
+ .recalc_rate = cken_recalc_rate,
+};
+
+static u8 cken_get_parent(struct clk_hw *hw)
+{
+ struct pxa_clk_cken *pclk = to_pxa_clk(hw);
+
+ if (!pclk->is_in_low_power)
+ return 0;
+ return pclk->is_in_low_power() ? 0 : 1;
+}
+
+static struct clk_ops cken_mux_ops = {
+ .get_parent = cken_get_parent,
+ .set_parent = dummy_clk_set_parent,
+};
+
+void __init clkdev_pxa_register(int ckid, const char *con_id,
+ const char *dev_id, struct clk *clk)
+{
+ if (!IS_ERR(clk) && (ckid != CLK_NONE))
+ pxa_clocks[ckid] = clk;
+ if (!IS_ERR(clk))
+ clk_register_clkdev(clk, con_id, dev_id);
+}
+
+int __init clk_pxa_cken_init(struct pxa_clk_cken *clks, int nb_clks)
+{
+ int i;
+ struct pxa_clk_cken *pclk;
+ struct clk *clk;
+
+ for (i = 0; i < nb_clks; i++) {
+ pclk = clks + i;
+ pclk->gate.lock = &lock;
+ clk = clk_register_composite(NULL, pclk->name,
+ pclk->parent_names, 2,
+ &pclk->hw, &cken_mux_ops,
+ &pclk->hw, &cken_rate_ops,
+ &pclk->gate.hw, &clk_gate_ops,
+ pclk->flags);
+ clkdev_pxa_register(pclk->ckid, pclk->con_id, pclk->dev_id,
+ clk);
+ }
+ return 0;
+}
+
+static void __init pxa_dt_clocks_init(struct device_node *np)
+{
+ of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data);
+}
+CLK_OF_DECLARE(pxa_clks, "marvell,pxa-clocks", pxa_dt_clocks_init);
diff --git a/drivers/clk/pxa/clk-pxa.h b/drivers/clk/pxa/clk-pxa.h
new file mode 100644
index 000000000000..5fe219d06b49
--- /dev/null
+++ b/drivers/clk/pxa/clk-pxa.h
@@ -0,0 +1,107 @@
+/*
+ * Marvell PXA family clocks
+ *
+ * Copyright (C) 2014 Robert Jarzmik
+ *
+ * Common clock code for PXA clocks ("CKEN" type clocks + DT)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ */
+#ifndef _CLK_PXA_
+#define _CLK_PXA_
+
+#define PARENTS(name) \
+ static const char *name ## _parents[] __initconst
+#define MUX_RO_RATE_RO_OPS(name, clk_name) \
+ static struct clk_hw name ## _mux_hw; \
+ static struct clk_hw name ## _rate_hw; \
+ static struct clk_ops name ## _mux_ops = { \
+ .get_parent = name ## _get_parent, \
+ .set_parent = dummy_clk_set_parent, \
+ }; \
+ static struct clk_ops name ## _rate_ops = { \
+ .recalc_rate = name ## _get_rate, \
+ }; \
+ static struct clk *clk_register_ ## name(void) \
+ { \
+ return clk_register_composite(NULL, clk_name, \
+ name ## _parents, \
+ ARRAY_SIZE(name ## _parents), \
+ &name ## _mux_hw, &name ## _mux_ops, \
+ &name ## _rate_hw, &name ## _rate_ops, \
+ NULL, NULL, CLK_GET_RATE_NOCACHE); \
+ }
+
+#define RATE_RO_OPS(name, clk_name) \
+ static struct clk_hw name ## _rate_hw; \
+ static struct clk_ops name ## _rate_ops = { \
+ .recalc_rate = name ## _get_rate, \
+ }; \
+ static struct clk *clk_register_ ## name(void) \
+ { \
+ return clk_register_composite(NULL, clk_name, \
+ name ## _parents, \
+ ARRAY_SIZE(name ## _parents), \
+ NULL, NULL, \
+ &name ## _rate_hw, &name ## _rate_ops, \
+ NULL, NULL, CLK_GET_RATE_NOCACHE); \
+ }
+
+/*
+ * CKEN clock type
+ * This clock takes it source from 2 possible parents :
+ * - a low power parent
+ * - a normal parent
+ *
+ * +------------+ +-----------+
+ * | Low Power | --- | x mult_lp |
+ * | Clock | | / div_lp |\
+ * +------------+ +-----------+ \+-----+ +-----------+
+ * | Mux |---| CKEN gate |
+ * +------------+ +-----------+ /+-----+ +-----------+
+ * | High Power | | x mult_hp |/
+ * | Clock | --- | / div_hp |
+ * +------------+ +-----------+
+ */
+struct pxa_clk_cken {
+ struct clk_hw hw;
+ int ckid;
+ const char *name;
+ const char *dev_id;
+ const char *con_id;
+ const char **parent_names;
+ struct clk_fixed_factor lp;
+ struct clk_fixed_factor hp;
+ struct clk_gate gate;
+ bool (*is_in_low_power)(void);
+ const unsigned long flags;
+};
+
+#define PXA_CKEN(_dev_id, _con_id, _name, parents, _mult_lp, _div_lp, \
+ _mult_hp, _div_hp, is_lp, _cken_reg, _cken_bit, flag) \
+ { .ckid = CLK_ ## _name, .name = #_name, \
+ .dev_id = _dev_id, .con_id = _con_id, .parent_names = parents,\
+ .lp = { .mult = _mult_lp, .div = _div_lp }, \
+ .hp = { .mult = _mult_hp, .div = _div_hp }, \
+ .is_in_low_power = is_lp, \
+ .gate = { .reg = (void __iomem *)_cken_reg, .bit_idx = _cken_bit }, \
+ .flags = flag, \
+ }
+#define PXA_CKEN_1RATE(dev_id, con_id, name, parents, cken_reg, \
+ cken_bit, flag) \
+ PXA_CKEN(dev_id, con_id, name, parents, 1, 1, 1, 1, \
+ NULL, cken_reg, cken_bit, flag)
+
+static int dummy_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+ return 0;
+}
+
+extern void clkdev_pxa_register(int ckid, const char *con_id,
+ const char *dev_id, struct clk *clk);
+extern int clk_pxa_cken_init(struct pxa_clk_cken *clks, int nb_clks);
+
+#endif