clk: add pxa25x clock drivers

Move pxa25x clock drivers from arch/arm/mach-pxa to driver/clk.
In the move :
 - convert to new clock framework legacy clocks
 - provide clocks as before for platform data based boards
 - provide clocks through devicetree with clk-pxa-dt

This is the preliminary step in the conversion. The remaining steps are
:
 - pxa3xx
 - once PXA is fully converted to device tree, if that happens,
   clk-pxa2* and clk-pxa3* should only hold the core clocks which cannot
   be described in devicetree.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Tested-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

drivers/clk/pxa/Makefile

@@ -1,2 +1,3 @@
 obj-y				+= clk-pxa.o
+obj-$(CONFIG_PXA25x)		+= clk-pxa25x.o
 obj-$(CONFIG_PXA27x)		+= clk-pxa27x.o

drivers/clk/pxa/clk-pxa25x.c

@@ -0,0 +1,273 @@
+/*
+ * Marvell PXA25x family clocks
+ *
+ * Copyright (C) 2014 Robert Jarzmik
+ *
+ * Heavily inspired from former arch/arm/mach-pxa/pxa25x.c.
+ *
+ * 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.
+ *
+ * For non-devicetree platforms. Once pxa is fully converted to devicetree, this
+ * should go away.
+ */
+#include <linux/clk-provider.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <mach/pxa25x.h>
+#include <mach/pxa2xx-regs.h>
+
+#include <dt-bindings/clock/pxa-clock.h>
+#include "clk-pxa.h"
+
+#define KHz 1000
+#define MHz (1000 * 1000)
+
+enum {
+	PXA_CORE_RUN = 0,
+	PXA_CORE_TURBO,
+};
+
+/*
+ * Various clock factors driven by the CCCR register.
+ */
+
+/* Crystal Frequency to Memory Frequency Multiplier (L) */
+static unsigned char L_clk_mult[32] = { 0, 27, 32, 36, 40, 45, 0, };
+
+/* Memory Frequency to Run Mode Frequency Multiplier (M) */
+static unsigned char M_clk_mult[4] = { 0, 1, 2, 4 };
+
+/* Run Mode Frequency to Turbo Mode Frequency Multiplier (N) */
+/* Note: we store the value N * 2 here. */
+static unsigned char N2_clk_mult[8] = { 0, 0, 2, 3, 4, 0, 6, 0 };
+
+static const char * const get_freq_khz[] = {
+	"core", "run", "cpll", "memory"
+};
+
+/*
+ * Get the clock frequency as reflected by CCCR and the turbo flag.
+ * We assume these values have been applied via a fcs.
+ * If info is not 0 we also display the current settings.
+ */
+unsigned int pxa25x_get_clk_frequency_khz(int info)
+{
+	struct clk *clk;
+	unsigned long clks[5];
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(get_freq_khz); i++) {
+		clk = clk_get(NULL, get_freq_khz[i]);
+		if (IS_ERR(clk)) {
+			clks[i] = 0;
+		} else {
+			clks[i] = clk_get_rate(clk);
+			clk_put(clk);
+		}
+	}
+
+	if (info) {
+		pr_info("Run Mode clock: %ld.%02ldMHz\n",
+			clks[1] / 1000000, (clks[1] % 1000000) / 10000);
+		pr_info("Turbo Mode clock: %ld.%02ldMHz\n",
+			clks[2] / 1000000, (clks[2] % 1000000) / 10000);
+		pr_info("Memory clock: %ld.%02ldMHz\n",
+			clks[3] / 1000000, (clks[3] % 1000000) / 10000);
+	}
+
+	return (unsigned int)clks[0];
+}
+
+static unsigned long clk_pxa25x_memory_get_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	unsigned long cccr = CCCR;
+	unsigned int m = M_clk_mult[(cccr >> 5) & 0x03];
+
+	return parent_rate / m;
+}
+PARENTS(clk_pxa25x_memory) = { "run" };
+RATE_RO_OPS(clk_pxa25x_memory, "memory");
+
+PARENTS(pxa25x_pbus95) = { "ppll_95_85mhz", "ppll_95_85mhz" };
+PARENTS(pxa25x_pbus147) = { "ppll_147_46mhz", "ppll_147_46mhz" };
+PARENTS(pxa25x_osc3) = { "osc_3_6864mhz", "osc_3_6864mhz" };
+
+#define PXA25X_CKEN(dev_id, con_id, parents, mult, div,			\
+		    bit, is_lp, flags)					\
+	PXA_CKEN(dev_id, con_id, bit, parents, mult, div, mult, div,	\
+		 is_lp,  &CKEN, CKEN_ ## bit, flags)
+#define PXA25X_PBUS95_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)	\
+	PXA25X_CKEN(dev_id, con_id, pxa25x_pbus95_parents, mult_hp,	\
+		    div_hp, bit, NULL, 0)
+#define PXA25X_PBUS147_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)\
+	PXA25X_CKEN(dev_id, con_id, pxa25x_pbus147_parents, mult_hp,	\
+		    div_hp, bit, NULL, 0)
+#define PXA25X_OSC3_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)	\
+	PXA25X_CKEN(dev_id, con_id, pxa25x_osc3_parents, mult_hp,	\
+		    div_hp, bit, NULL, 0)
+
+#define PXA25X_CKEN_1RATE(dev_id, con_id, bit, parents, delay)		\
+	PXA_CKEN_1RATE(dev_id, con_id, bit, parents,			\
+		       &CKEN, CKEN_ ## bit, 0)
+#define PXA25X_CKEN_1RATE_AO(dev_id, con_id, bit, parents, delay)	\
+	PXA_CKEN_1RATE(dev_id, con_id, bit, parents,			\
+		       &CKEN, CKEN_ ## bit, CLK_IGNORE_UNUSED)
+
+static struct desc_clk_cken pxa25x_clocks[] __initdata = {
+	PXA25X_PBUS95_CKEN("pxa2xx-mci.0", NULL, MMC, 1, 5, 0),
+	PXA25X_PBUS95_CKEN("pxa2xx-i2c.0", NULL, I2C, 1, 3, 0),
+	PXA25X_PBUS95_CKEN("pxa2xx-ir", "FICPCLK", FICP, 1, 2, 0),
+	PXA25X_PBUS95_CKEN("pxa25x-udc", NULL, USB, 1, 2, 5),
+	PXA25X_PBUS147_CKEN("pxa2xx-uart.0", NULL, FFUART, 1, 10, 1),
+	PXA25X_PBUS147_CKEN("pxa2xx-uart.1", NULL, BTUART, 1, 10, 1),
+	PXA25X_PBUS147_CKEN("pxa2xx-uart.2", NULL, STUART, 1, 10, 1),
+	PXA25X_PBUS147_CKEN("pxa2xx-uart.3", NULL, HWUART, 1, 10, 1),
+	PXA25X_PBUS147_CKEN("pxa2xx-i2s", NULL, I2S, 1, 10, 0),
+	PXA25X_PBUS147_CKEN(NULL, "AC97CLK", AC97, 1, 12, 0),
+	PXA25X_OSC3_CKEN("pxa25x-ssp.0", NULL, SSP, 1, 1, 0),
+	PXA25X_OSC3_CKEN("pxa25x-nssp.1", NULL, NSSP, 1, 1, 0),
+	PXA25X_OSC3_CKEN("pxa25x-nssp.2", NULL, ASSP, 1, 1, 0),
+	PXA25X_OSC3_CKEN("pxa25x-pwm.0", NULL, PWM0, 1, 1, 0),
+	PXA25X_OSC3_CKEN("pxa25x-pwm.1", NULL, PWM1, 1, 1, 0),
+
+	PXA25X_CKEN_1RATE("pxa2xx-fb", NULL, LCD, clk_pxa25x_memory_parents, 0),
+	PXA25X_CKEN_1RATE_AO("pxa2xx-pcmcia", NULL, MEMC,
+			     clk_pxa25x_memory_parents, 0),
+};
+
+static u8 clk_pxa25x_core_get_parent(struct clk_hw *hw)
+{
+	unsigned long clkcfg;
+	unsigned int t;
+
+	asm("mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
+	t  = clkcfg & (1 << 0);
+	if (t)
+		return PXA_CORE_TURBO;
+	return PXA_CORE_RUN;
+}
+
+static unsigned long clk_pxa25x_core_get_rate(struct clk_hw *hw,
+					      unsigned long parent_rate)
+{
+	return parent_rate;
+}
+PARENTS(clk_pxa25x_core) = { "run", "cpll" };
+MUX_RO_RATE_RO_OPS(clk_pxa25x_core, "core");
+
+static unsigned long clk_pxa25x_run_get_rate(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	unsigned long cccr = CCCR;
+	unsigned int n2 = N2_clk_mult[(cccr >> 7) & 0x07];
+
+	return (parent_rate / n2) * 2;
+}
+PARENTS(clk_pxa25x_run) = { "cpll" };
+RATE_RO_OPS(clk_pxa25x_run, "run");
+
+static unsigned long clk_pxa25x_cpll_get_rate(struct clk_hw *hw,
+	unsigned long parent_rate)
+{
+	unsigned long clkcfg, cccr = CCCR;
+	unsigned int l, m, n2, t;
+
+	asm("mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
+	t = clkcfg & (1 << 0);
+	l  =  L_clk_mult[(cccr >> 0) & 0x1f];
+	m = M_clk_mult[(cccr >> 5) & 0x03];
+	n2 = N2_clk_mult[(cccr >> 7) & 0x07];
+
+	if (t)
+		return m * l * n2 * parent_rate / 2;
+	return m * l * parent_rate;
+}
+PARENTS(clk_pxa25x_cpll) = { "osc_3_6864mhz" };
+RATE_RO_OPS(clk_pxa25x_cpll, "cpll");
+
+static void __init pxa25x_register_core(void)
+{
+	clk_register_clk_pxa25x_cpll();
+	clk_register_clk_pxa25x_run();
+	clkdev_pxa_register(CLK_CORE, "core", NULL,
+			    clk_register_clk_pxa25x_core());
+}
+
+static void __init pxa25x_register_plls(void)
+{
+	clk_register_fixed_rate(NULL, "osc_3_6864mhz", NULL,
+				CLK_GET_RATE_NOCACHE | CLK_IS_ROOT,
+				3686400);
+	clk_register_fixed_rate(NULL, "osc_32_768khz", NULL,
+				CLK_GET_RATE_NOCACHE | CLK_IS_ROOT,
+				32768);
+	clk_register_fixed_rate(NULL, "clk_dummy", NULL, CLK_IS_ROOT, 0);
+	clk_register_fixed_factor(NULL, "ppll_95_85mhz", "osc_3_6864mhz",
+				  0, 26, 1);
+	clk_register_fixed_factor(NULL, "ppll_147_46mhz", "osc_3_6864mhz",
+				  0, 40, 1);
+}
+
+static void __init pxa25x_base_clocks_init(void)
+{
+	pxa25x_register_plls();
+	pxa25x_register_core();
+	clk_register_clk_pxa25x_memory();
+}
+
+#define DUMMY_CLK(_con_id, _dev_id, _parent) \
+	{ .con_id = _con_id, .dev_id = _dev_id, .parent = _parent }
+struct dummy_clk {
+	const char *con_id;
+	const char *dev_id;
+	const char *parent;
+};
+static struct dummy_clk dummy_clks[] __initdata = {
+	DUMMY_CLK(NULL, "pxa25x-gpio", "osc_32_768khz"),
+	DUMMY_CLK(NULL, "pxa26x-gpio", "osc_32_768khz"),
+	DUMMY_CLK("GPIO11_CLK", NULL, "osc_3_6864mhz"),
+	DUMMY_CLK("GPIO12_CLK", NULL, "osc_32_768khz"),
+	DUMMY_CLK(NULL, "sa1100-rtc", "osc_32_768khz"),
+	DUMMY_CLK("OSTIMER0", NULL, "osc_32_768khz"),
+	DUMMY_CLK("UARTCLK", "pxa2xx-ir", "STUART"),
+};
+
+static void __init pxa25x_dummy_clocks_init(void)
+{
+	struct clk *clk;
+	struct dummy_clk *d;
+	const char *name;
+	int i;
+
+	/*
+	 * All pinctrl logic has been wiped out of the clock driver, especially
+	 * for gpio11 and gpio12 outputs. Machine code should ensure proper pin
+	 * control (ie. pxa2xx_mfp_config() invocation).
+	 */
+	for (i = 0; i < ARRAY_SIZE(dummy_clks); i++) {
+		d = &dummy_clks[i];
+		name = d->dev_id ? d->dev_id : d->con_id;
+		clk = clk_register_fixed_factor(NULL, name, d->parent, 0, 1, 1);
+		clk_register_clkdev(clk, d->con_id, d->dev_id);
+	}
+}
+
+int __init pxa25x_clocks_init(void)
+{
+	pxa25x_base_clocks_init();
+	pxa25x_dummy_clocks_init();
+	return clk_pxa_cken_init(pxa25x_clocks, ARRAY_SIZE(pxa25x_clocks));
+}
+
+static void __init pxa25x_dt_clocks_init(struct device_node *np)
+{
+	pxa25x_clocks_init();
+	clk_pxa_dt_common_init(np);
+}
+CLK_OF_DECLARE(pxa25x_clks, "marvell,pxa250-core-clocks",
+	       pxa25x_dt_clocks_init);