MIPS: Alchemy: clock framework integration of onchip clocks

This patch introduces common clock framework integration for all
configurable on-chip clocks on Alchemy chips:

- 2 or 3 PLLs which generate integer multiples of the root rate 12MHz,
- 6 dividers which take one of the 3 PLLs as input and divide their
  rate by either multiples of 2 or 1 (Au1300).
- another bank of up to 6 muxes which take either one of the 6
  above dividers or one of the PLLs directly and divide their rate
  further by 1, 2, 3 or 4.
- a few other sources which are used by onchip peripherals and are
  informational.

This implementation will take the clock tree as it was set up
by boot firmware: all in-kernel boards should continue to work
without having to set up the clock tree in board code.

CLK_IGNORE_DISABLED will be removed once all drivers have been
converted.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/7466/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 1098 insertions, 2 deletions

diff --git a/arch/mips/alchemy/common/Makefile b/arch/mips/alchemy/common/Makefile
index cb83d8d21aef..c8dedcb23e8e 100644
--- a/arch/mips/alchemy/common/Makefile
+++ b/arch/mips/alchemy/common/Makefile
@@ -5,8 +5,8 @@
 # Makefile for the Alchemy Au1xx0 CPUs, generic files.
 #
 
-obj-y += prom.o time.o clocks.o platform.o power.o setup.o \
-	sleeper.o dma.o dbdma.o vss.o irq.o usb.o
+obj-y += prom.o time.o clock.o clocks.o platform.o power.o \
+	 setup.o sleeper.o dma.o dbdma.o vss.o irq.o usb.o
 
 # optional gpiolib support
 ifeq ($(CONFIG_ALCHEMY_GPIO_INDIRECT),)
diff --git a/arch/mips/alchemy/common/clock.c b/arch/mips/alchemy/common/clock.c
new file mode 100644
index 000000000000..3cd4118e49fe
--- /dev/null
+++ b/arch/mips/alchemy/common/clock.c
@@ -0,0 +1,1096 @@
+/*
+ * Alchemy clocks.
+ *
+ * Exposes all configurable internal clock sources to the clk framework.
+ *
+ * We have:
+ *  - Root source, usually 12MHz supplied by an external crystal
+ *  - 3 PLLs which generate multiples of root rate [AUX, CPU, AUX2]
+ *
+ * Dividers:
+ *  - 6 clock dividers with:
+ *   * selectable source [one of the PLLs],
+ *   * output divided between [2 .. 512 in steps of 2] (!Au1300)
+ *     or [1 .. 256 in steps of 1] (Au1300),
+ *   * can be enabled individually.
+ *
+ * - up to 6 "internal" (fixed) consumers which:
+ *   * take either AUXPLL or one of the above 6 dividers as input,
+ *   * divide this input by 1, 2, or 4 (and 3 on Au1300).
+ *   * can be disabled separately.
+ *
+ * Misc clocks:
+ * - sysbus clock: CPU core clock (CPUPLL) divided by 2, 3 or 4.
+ *    depends on board design and should be set by bootloader, read-only.
+ * - peripheral clock: half the rate of sysbus clock, source for a lot
+ *    of peripheral blocks, read-only.
+ * - memory clock: clk rate to main memory chips, depends on board
+ *    design and is read-only,
+ * - lrclk: the static bus clock signal for synchronous operation.
+ *    depends on board design, must be set by bootloader,
+ *    but may be required to correctly configure devices attached to
+ *    the static bus. The Au1000/1500/1100 manuals call it LCLK, on
+ *    later models it's called RCLK.
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk-private.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <asm/mach-au1x00/au1000.h>
+
+/* Base clock: 12MHz is the default in all databooks, and I haven't
+ * found any board yet which uses a different rate.
+ */
+#define ALCHEMY_ROOTCLK_RATE	12000000
+
+/*
+ * the internal sources which can be driven by the PLLs and dividers.
+ * Names taken from the databooks, refer to them for more information,
+ * especially which ones are share a clock line.
+ */
+static const char * const alchemy_au1300_intclknames[] = {
+	"lcd_intclk", "gpemgp_clk", "maempe_clk", "maebsa_clk",
+	"EXTCLK0", "EXTCLK1"
+};
+
+static const char * const alchemy_au1200_intclknames[] = {
+	"lcd_intclk", NULL, NULL, NULL, "EXTCLK0", "EXTCLK1"
+};
+
+static const char * const alchemy_au1550_intclknames[] = {
+	"usb_clk", "psc0_intclk", "psc1_intclk", "pci_clko",
+	"EXTCLK0", "EXTCLK1"
+};
+
+static const char * const alchemy_au1100_intclknames[] = {
+	"usb_clk", "lcd_intclk", NULL, "i2s_clk", "EXTCLK0", "EXTCLK1"
+};
+
+static const char * const alchemy_au1500_intclknames[] = {
+	NULL, "usbd_clk", "usbh_clk", "pci_clko", "EXTCLK0", "EXTCLK1"
+};
+
+static const char * const alchemy_au1000_intclknames[] = {
+	"irda_clk", "usbd_clk", "usbh_clk", "i2s_clk", "EXTCLK0",
+	"EXTCLK1"
+};
+
+/* aliases for a few on-chip sources which are either shared
+ * or have gone through name changes.
+ */
+static struct clk_aliastable {
+	char *alias;
+	char *base;
+	int cputype;
+} alchemy_clk_aliases[] __initdata = {
+	{ "usbh_clk", "usb_clk",    ALCHEMY_CPU_AU1100 },
+	{ "usbd_clk", "usb_clk",    ALCHEMY_CPU_AU1100 },
+	{ "irda_clk", "usb_clk",    ALCHEMY_CPU_AU1100 },
+	{ "usbh_clk", "usb_clk",    ALCHEMY_CPU_AU1550 },
+	{ "usbd_clk", "usb_clk",    ALCHEMY_CPU_AU1550 },
+	{ "psc2_intclk", "usb_clk", ALCHEMY_CPU_AU1550 },
+	{ "psc3_intclk", "EXTCLK0", ALCHEMY_CPU_AU1550 },
+	{ "psc0_intclk", "EXTCLK0", ALCHEMY_CPU_AU1200 },
+	{ "psc1_intclk", "EXTCLK1", ALCHEMY_CPU_AU1200 },
+	{ "psc0_intclk", "EXTCLK0", ALCHEMY_CPU_AU1300 },
+	{ "psc2_intclk", "EXTCLK0", ALCHEMY_CPU_AU1300 },
+	{ "psc1_intclk", "EXTCLK1", ALCHEMY_CPU_AU1300 },
+	{ "psc3_intclk", "EXTCLK1", ALCHEMY_CPU_AU1300 },
+
+	{ NULL, NULL, 0 },
+};
+
+#define IOMEM(x)	((void __iomem *)(KSEG1ADDR(CPHYSADDR(x))))
+
+/* access locks to SYS_FREQCTRL0/1 and SYS_CLKSRC registers */
+static spinlock_t alchemy_clk_fg0_lock;
+static spinlock_t alchemy_clk_fg1_lock;
+static spinlock_t alchemy_clk_csrc_lock;
+
+/* CPU Core clock *****************************************************/
+
+static unsigned long alchemy_clk_cpu_recalc(struct clk_hw *hw,
+					    unsigned long parent_rate)
+{
+	unsigned long t;
+
+	/*
+	 * On early Au1000, sys_cpupll was write-only. Since these
+	 * silicon versions of Au1000 are not sold, we don't bend
+	 * over backwards trying to determine the frequency.
+	 */
+	if (unlikely(au1xxx_cpu_has_pll_wo()))
+		t = 396000000;
+	else {
+		t = alchemy_rdsys(AU1000_SYS_CPUPLL) & 0x7f;
+		t *= parent_rate;
+	}
+
+	return t;
+}
+
+static struct clk_ops alchemy_clkops_cpu = {
+	.recalc_rate	= alchemy_clk_cpu_recalc,
+};
+
+static struct clk __init *alchemy_clk_setup_cpu(const char *parent_name,
+						int ctype)
+{
+	struct clk_init_data id;
+	struct clk_hw *h;
+
+	h = kzalloc(sizeof(*h), GFP_KERNEL);
+	if (!h)
+		return ERR_PTR(-ENOMEM);
+
+	id.name = ALCHEMY_CPU_CLK;
+	id.parent_names = &parent_name;
+	id.num_parents = 1;
+	id.flags = CLK_IS_BASIC | CLK_IGNORE_UNUSED;
+	id.ops = &alchemy_clkops_cpu;
+	h->init = &id;
+
+	return clk_register(NULL, h);
+}
+
+/* AUXPLLs ************************************************************/
+
+struct alchemy_auxpll_clk {
+	struct clk_hw hw;
+	unsigned long reg;	/* au1300 has also AUXPLL2 */
+	int maxmult;		/* max multiplier */
+};
+#define to_auxpll_clk(x) container_of(x, struct alchemy_auxpll_clk, hw)
+
+static unsigned long alchemy_clk_aux_recalc(struct clk_hw *hw,
+					    unsigned long parent_rate)
+{
+	struct alchemy_auxpll_clk *a = to_auxpll_clk(hw);
+
+	return (alchemy_rdsys(a->reg) & 0xff) * parent_rate;
+}
+
+static int alchemy_clk_aux_setr(struct clk_hw *hw,
+				unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct alchemy_auxpll_clk *a = to_auxpll_clk(hw);
+	unsigned long d = rate;
+
+	if (rate)
+		d /= parent_rate;
+	else
+		d = 0;
+
+	/* minimum is 84MHz, max is 756-1032 depending on variant */
+	if (((d < 7) && (d != 0)) || (d > a->maxmult))
+		return -EINVAL;
+
+	alchemy_wrsys(d, a->reg);
+	return 0;
+}
+
+static long alchemy_clk_aux_roundr(struct clk_hw *hw,
+					    unsigned long rate,
+					    unsigned long *parent_rate)
+{
+	struct alchemy_auxpll_clk *a = to_auxpll_clk(hw);
+	unsigned long mult;
+
+	if (!rate || !*parent_rate)
+		return 0;
+
+	mult = rate / (*parent_rate);
+
+	if (mult && (mult < 7))
+		mult = 7;
+	if (mult > a->maxmult)
+		mult = a->maxmult;
+
+	return (*parent_rate) * mult;
+}
+
+static struct clk_ops alchemy_clkops_aux = {
+	.recalc_rate	= alchemy_clk_aux_recalc,
+	.set_rate	= alchemy_clk_aux_setr,
+	.round_rate	= alchemy_clk_aux_roundr,
+};
+
+static struct clk __init *alchemy_clk_setup_aux(const char *parent_name,
+						char *name, int maxmult,
+						unsigned long reg)
+{
+	struct clk_init_data id;
+	struct clk *c;
+	struct alchemy_auxpll_clk *a;
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return ERR_PTR(-ENOMEM);
+
+	id.name = name;
+	id.parent_names = &parent_name;
+	id.num_parents = 1;
+	id.flags = CLK_GET_RATE_NOCACHE | CLK_IGNORE_UNUSED;
+	id.ops = &alchemy_clkops_aux;
+
+	a->reg = reg;
+	a->maxmult = maxmult;
+	a->hw.init = &id;
+
+	c = clk_register(NULL, &a->hw);
+	if (!IS_ERR(c))
+		clk_register_clkdev(c, name, NULL);
+	else
+		kfree(a);
+
+	return c;
+}
+
+/* sysbus_clk *********************************************************/
+
+static struct clk __init  *alchemy_clk_setup_sysbus(const char *pn)
+{
+	unsigned long v = (alchemy_rdsys(AU1000_SYS_POWERCTRL) & 3) + 2;
+	struct clk *c;
+
+	c = clk_register_fixed_factor(NULL, ALCHEMY_SYSBUS_CLK,
+				      pn, 0, 1, v);
+	if (!IS_ERR(c))
+		clk_register_clkdev(c, ALCHEMY_SYSBUS_CLK, NULL);
+	return c;
+}
+
+/* Peripheral Clock ***************************************************/
+
+static struct clk __init *alchemy_clk_setup_periph(const char *pn)
+{
+	/* Peripheral clock runs at half the rate of sysbus clk */
+	struct clk *c;
+
+	c = clk_register_fixed_factor(NULL, ALCHEMY_PERIPH_CLK,
+				      pn, 0, 1, 2);
+	if (!IS_ERR(c))
+		clk_register_clkdev(c, ALCHEMY_PERIPH_CLK, NULL);
+	return c;
+}
+
+/* mem clock **********************************************************/
+
+static struct clk __init *alchemy_clk_setup_mem(const char *pn, int ct)
+{
+	void __iomem *addr = IOMEM(AU1000_MEM_PHYS_ADDR);
+	unsigned long v;
+	struct clk *c;
+	int div;
+
+	switch (ct) {
+	case ALCHEMY_CPU_AU1550:
+	case ALCHEMY_CPU_AU1200:
+		v = __raw_readl(addr + AU1550_MEM_SDCONFIGB);
+		div = (v & (1 << 15)) ? 1 : 2;
+		break;
+	case ALCHEMY_CPU_AU1300:
+		v = __raw_readl(addr + AU1550_MEM_SDCONFIGB);
+		div = (v & (1 << 31)) ? 1 : 2;
+		break;
+	case ALCHEMY_CPU_AU1000:
+	case ALCHEMY_CPU_AU1500:
+	case ALCHEMY_CPU_AU1100:
+	default:
+		div = 2;
+		break;
+	}
+
+	c = clk_register_fixed_factor(NULL, ALCHEMY_MEM_CLK, pn,
+				      0, 1, div);
+	if (!IS_ERR(c))
+		clk_register_clkdev(c, ALCHEMY_MEM_CLK, NULL);
+	return c;
+}
+
+/* lrclk: external synchronous static bus clock ***********************/
+
+static struct clk __init *alchemy_clk_setup_lrclk(const char *pn)
+{
+	/* MEM_STCFG0[15:13] = divisor.
+	 * L/RCLK = periph_clk / (divisor + 1)
+	 * On Au1000, Au1500, Au1100 it's called LCLK,
+	 * on later models it's called RCLK, but it's the same thing.
+	 */
+	struct clk *c;
+	unsigned long v = alchemy_rdsmem(AU1000_MEM_STCFG0) >> 13;
+
+	v = (v & 7) + 1;
+	c = clk_register_fixed_factor(NULL, ALCHEMY_LR_CLK,
+				      pn, 0, 1, v);
+	if (!IS_ERR(c))
+		clk_register_clkdev(c, ALCHEMY_LR_CLK, NULL);
+	return c;
+}
+
+/* Clock dividers and muxes *******************************************/
+
+/* data for fgen and csrc mux-dividers */
+struct alchemy_fgcs_clk {
+	struct clk_hw hw;
+	spinlock_t *reglock;	/* register lock		  */
+	unsigned long reg;	/* SYS_FREQCTRL0/1		  */
+	int shift;		/* offset in register		  */
+	int parent;		/* parent before disable [Au1300] */
+	int isen;		/* is it enabled?		  */
+	int *dt;		/* dividertable for csrc	  */
+};
+#define to_fgcs_clk(x) container_of(x, struct alchemy_fgcs_clk, hw)
+
+static long alchemy_calc_div(unsigned long rate, unsigned long prate,
+			       int scale, int maxdiv, unsigned long *rv)
+{
+	long div1, div2;
+
+	div1 = prate / rate;
+	if ((prate / div1) > rate)
+		div1++;
+
+	if (scale == 2) {	/* only div-by-multiple-of-2 possible */
+		if (div1 & 1)
+			div1++;	/* stay <=prate */
+	}
+
+	div2 = (div1 / scale) - 1;	/* value to write to register */
+
+	if (div2 > maxdiv)
+		div2 = maxdiv;
+	if (rv)
+		*rv = div2;
+
+	div1 = ((div2 + 1) * scale);
+	return div1;
+}
+
+static long alchemy_clk_fgcs_detr(struct clk_hw *hw, unsigned long rate,
+					unsigned long *best_parent_rate,
+					struct clk **best_parent_clk,
+					int scale, int maxdiv)
+{
+	struct clk *pc, *bpc, *free;
+	long tdv, tpr, pr, nr, br, bpr, diff, lastdiff;
+	int j;
+
+	lastdiff = INT_MAX;
+	bpr = 0;
+	bpc = NULL;
+	br = -EINVAL;
+	free = NULL;
+
+	/* look at the rates each enabled parent supplies and select
+	 * the one that gets closest to but not over the requested rate.
+	 */
+	for (j = 0; j < 7; j++) {
+		pc = clk_get_parent_by_index(hw->clk, j);
+		if (!pc)
+			break;
+
+		/* if this parent is currently unused, remember it.
+		 * XXX: I know it's a layering violation, but it works
+		 * so well.. (if (!clk_has_active_children(pc)) )
+		 */
+		if (pc->prepare_count == 0) {
+			if (!free)
+				free = pc;
+		}
+
+		pr = clk_get_rate(pc);
+		if (pr < rate)
+			continue;
+
+		/* what can hardware actually provide */
+		tdv = alchemy_calc_div(rate, pr, scale, maxdiv, NULL);
+		nr = pr / tdv;
+		diff = rate - nr;
+		if (nr > rate)
+			continue;
+
+		if (diff < lastdiff) {
+			lastdiff = diff;
+			bpr = pr;
+			bpc = pc;
+			br = nr;
+		}
+		if (diff == 0)
+			break;
+	}
+
+	/* if we couldn't get the exact rate we wanted from the enabled
+	 * parents, maybe we can tell an available disabled/inactive one
+	 * to give us a rate we can divide down to the requested rate.
+	 */
+	if (lastdiff && free) {
+		for (j = (maxdiv == 4) ? 1 : scale; j <= maxdiv; j += scale) {
+			tpr = rate * j;
+			if (tpr < 0)
+				break;
+			pr = clk_round_rate(free, tpr);
+
+			tdv = alchemy_calc_div(rate, pr, scale, maxdiv, NULL);
+			nr = pr / tdv;
+			diff = rate - nr;
+			if (nr > rate)
+				continue;
+			if (diff < lastdiff) {
+				lastdiff = diff;
+				bpr = pr;
+				bpc = free;
+				br = nr;
+			}
+			if (diff == 0)
+				break;
+		}
+	}
+
+	*best_parent_rate = bpr;
+	*best_parent_clk = bpc;
+	return br;
+}
+
+static int alchemy_clk_fgv1_en(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v, flags;
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	v |= (1 << 1) << c->shift;
+	alchemy_wrsys(v, c->reg);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static int alchemy_clk_fgv1_isen(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v = alchemy_rdsys(c->reg) >> (c->shift + 1);
+
+	return v & 1;
+}
+
+static void alchemy_clk_fgv1_dis(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v, flags;
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	v &= ~((1 << 1) << c->shift);
+	alchemy_wrsys(v, c->reg);
+	spin_unlock_irqrestore(c->reglock, flags);
+}
+
+static int alchemy_clk_fgv1_setp(struct clk_hw *hw, u8 index)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v, flags;
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	if (index)
+		v |= (1 << c->shift);
+	else
+		v &= ~(1 << c->shift);
+	alchemy_wrsys(v, c->reg);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static u8 alchemy_clk_fgv1_getp(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+
+	return (alchemy_rdsys(c->reg) >> c->shift) & 1;
+}
+
+static int alchemy_clk_fgv1_setr(struct clk_hw *hw, unsigned long rate,
+				 unsigned long parent_rate)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long div, v, flags, ret;
+	int sh = c->shift + 2;
+
+	if (!rate || !parent_rate || rate > (parent_rate / 2))
+		return -EINVAL;
+	ret = alchemy_calc_div(rate, parent_rate, 2, 512, &div);
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	v &= ~(0xff << sh);
+	v |= div << sh;
+	alchemy_wrsys(v, c->reg);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static unsigned long alchemy_clk_fgv1_recalc(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v = alchemy_rdsys(c->reg) >> (c->shift + 2);
+
+	v = ((v & 0xff) + 1) * 2;
+	return parent_rate / v;
+}
+
+static long alchemy_clk_fgv1_detr(struct clk_hw *hw, unsigned long rate,
+					unsigned long *best_parent_rate,
+					struct clk **best_parent_clk)
+{
+	return alchemy_clk_fgcs_detr(hw, rate, best_parent_rate,
+				     best_parent_clk, 2, 512);
+}
+
+/* Au1000, Au1100, Au15x0, Au12x0 */
+static struct clk_ops alchemy_clkops_fgenv1 = {
+	.recalc_rate	= alchemy_clk_fgv1_recalc,
+	.determine_rate	= alchemy_clk_fgv1_detr,
+	.set_rate	= alchemy_clk_fgv1_setr,
+	.set_parent	= alchemy_clk_fgv1_setp,
+	.get_parent	= alchemy_clk_fgv1_getp,
+	.enable		= alchemy_clk_fgv1_en,
+	.disable	= alchemy_clk_fgv1_dis,
+	.is_enabled	= alchemy_clk_fgv1_isen,
+};
+
+static void __alchemy_clk_fgv2_en(struct alchemy_fgcs_clk *c)
+{
+	unsigned long v = alchemy_rdsys(c->reg);
+
+	v &= ~(3 << c->shift);
+	v |= (c->parent & 3) << c->shift;
+	alchemy_wrsys(v, c->reg);
+	c->isen = 1;
+}
+
+static int alchemy_clk_fgv2_en(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long flags;
+
+	/* enable by setting the previous parent clock */
+	spin_lock_irqsave(c->reglock, flags);
+	__alchemy_clk_fgv2_en(c);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static int alchemy_clk_fgv2_isen(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+
+	return ((alchemy_rdsys(c->reg) >> c->shift) & 3) != 0;
+}
+
+static void alchemy_clk_fgv2_dis(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v, flags;
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	v &= ~(3 << c->shift);	/* set input mux to "disabled" state */
+	alchemy_wrsys(v, c->reg);
+	c->isen = 0;
+	spin_unlock_irqrestore(c->reglock, flags);
+}
+
+static int alchemy_clk_fgv2_setp(struct clk_hw *hw, u8 index)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long flags;
+
+	spin_lock_irqsave(c->reglock, flags);
+	c->parent = index + 1;	/* value to write to register */
+	if (c->isen)
+		__alchemy_clk_fgv2_en(c);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static u8 alchemy_clk_fgv2_getp(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long flags, v;
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = c->parent - 1;
+	spin_unlock_irqrestore(c->reglock, flags);
+	return v;
+}
+
+/* fg0-2 and fg4-6 share a "scale"-bit. With this bit cleared, the
+ * dividers behave exactly as on previous models (dividers are multiples
+ * of 2); with the bit set, dividers are multiples of 1, halving their
+ * range, but making them also much more flexible.
+ */
+static int alchemy_clk_fgv2_setr(struct clk_hw *hw, unsigned long rate,
+				 unsigned long parent_rate)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	int sh = c->shift + 2;
+	unsigned long div, v, flags, ret;
+
+	if (!rate || !parent_rate || rate > parent_rate)
+		return -EINVAL;
+
+	v = alchemy_rdsys(c->reg) & (1 << 30); /* test "scale" bit */
+	ret = alchemy_calc_div(rate, parent_rate, v ? 1 : 2,
+			       v ? 256 : 512, &div);
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	v &= ~(0xff << sh);
+	v |= (div & 0xff) << sh;
+	alchemy_wrsys(v, c->reg);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static unsigned long alchemy_clk_fgv2_recalc(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	int sh = c->shift + 2;
+	unsigned long v, t;
+
+	v = alchemy_rdsys(c->reg);
+	t = parent_rate / (((v >> sh) & 0xff) + 1);
+	if ((v & (1 << 30)) == 0)		/* test scale bit */
+		t /= 2;
+
+	return t;
+}
+
+static long alchemy_clk_fgv2_detr(struct clk_hw *hw, unsigned long rate,
+					unsigned long *best_parent_rate,
+					struct clk **best_parent_clk)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	int scale, maxdiv;
+
+	if (alchemy_rdsys(c->reg) & (1 << 30)) {
+		scale = 1;
+		maxdiv = 256;
+	} else {
+		scale = 2;
+		maxdiv = 512;
+	}
+
+	return alchemy_clk_fgcs_detr(hw, rate, best_parent_rate,
+				     best_parent_clk, scale, maxdiv);
+}
+
+/* Au1300 larger input mux, no separate disable bit, flexible divider */
+static struct clk_ops alchemy_clkops_fgenv2 = {
+	.recalc_rate	= alchemy_clk_fgv2_recalc,
+	.determine_rate	= alchemy_clk_fgv2_detr,
+	.set_rate	= alchemy_clk_fgv2_setr,
+	.set_parent	= alchemy_clk_fgv2_setp,
+	.get_parent	= alchemy_clk_fgv2_getp,
+	.enable		= alchemy_clk_fgv2_en,
+	.disable	= alchemy_clk_fgv2_dis,
+	.is_enabled	= alchemy_clk_fgv2_isen,
+};
+
+static const char * const alchemy_clk_fgv1_parents[] = {
+	ALCHEMY_CPU_CLK, ALCHEMY_AUXPLL_CLK
+};
+
+static const char * const alchemy_clk_fgv2_parents[] = {
+	ALCHEMY_AUXPLL2_CLK, ALCHEMY_CPU_CLK, ALCHEMY_AUXPLL_CLK
+};
+
+static const char * const alchemy_clk_fgen_names[] = {
+	ALCHEMY_FG0_CLK, ALCHEMY_FG1_CLK, ALCHEMY_FG2_CLK,
+	ALCHEMY_FG3_CLK, ALCHEMY_FG4_CLK, ALCHEMY_FG5_CLK };
+
+static int __init alchemy_clk_init_fgens(int ctype)
+{
+	struct clk *c;
+	struct clk_init_data id;
+	struct alchemy_fgcs_clk *a;
+	unsigned long v;
+	int i, ret;
+
+	switch (ctype) {
+	case ALCHEMY_CPU_AU1000...ALCHEMY_CPU_AU1200:
+		id.ops = &alchemy_clkops_fgenv1;
+		id.parent_names = (const char **)alchemy_clk_fgv1_parents;
+		id.num_parents = 2;
+		break;
+	case ALCHEMY_CPU_AU1300:
+		id.ops = &alchemy_clkops_fgenv2;
+		id.parent_names = (const char **)alchemy_clk_fgv2_parents;
+		id.num_parents = 3;
+		break;
+	default:
+		return -ENODEV;
+	}
+	id.flags = CLK_SET_RATE_PARENT | CLK_GET_RATE_NOCACHE |
+		   CLK_IGNORE_UNUSED;
+
+	a = kzalloc((sizeof(*a)) * 6, GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	spin_lock_init(&alchemy_clk_fg0_lock);
+	spin_lock_init(&alchemy_clk_fg1_lock);
+	ret = 0;
+	for (i = 0; i < 6; i++) {
+		id.name = alchemy_clk_fgen_names[i];
+		a->shift = 10 * (i < 3 ? i : i - 3);
+		if (i > 2) {
+			a->reg = AU1000_SYS_FREQCTRL1;
+			a->reglock = &alchemy_clk_fg1_lock;
+		} else {
+			a->reg = AU1000_SYS_FREQCTRL0;
+			a->reglock = &alchemy_clk_fg0_lock;
+		}
+
+		/* default to first parent if bootloader has set
+		 * the mux to disabled state.
+		 */
+		if (ctype == ALCHEMY_CPU_AU1300) {
+			v = alchemy_rdsys(a->reg);
+			a->parent = (v >> a->shift) & 3;
+			if (!a->parent) {
+				a->parent = 1;
+				a->isen = 0;
+			} else
+				a->isen = 1;
+		}
+
+		a->hw.init = &id;
+		c = clk_register(NULL, &a->hw);
+		if (IS_ERR(c))
+			ret++;
+		else
+			clk_register_clkdev(c, id.name, NULL);
+		a++;
+	}
+
+	return ret;
+}
+
+/* internal sources muxes *********************************************/
+
+static int alchemy_clk_csrc_isen(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v = alchemy_rdsys(c->reg);
+
+	return (((v >> c->shift) >> 2) & 7) != 0;
+}
+
+static void __alchemy_clk_csrc_en(struct alchemy_fgcs_clk *c)
+{
+	unsigned long v = alchemy_rdsys(c->reg);
+
+	v &= ~((7 << 2) << c->shift);
+	v |= ((c->parent & 7) << 2) << c->shift;
+	alchemy_wrsys(v, c->reg);
+	c->isen = 1;
+}
+
+static int alchemy_clk_csrc_en(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long flags;
+
+	/* enable by setting the previous parent clock */
+	spin_lock_irqsave(c->reglock, flags);
+	__alchemy_clk_csrc_en(c);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static void alchemy_clk_csrc_dis(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v, flags;
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	v &= ~((3 << 2) << c->shift);	/* mux to "disabled" state */
+	alchemy_wrsys(v, c->reg);
+	c->isen = 0;
+	spin_unlock_irqrestore(c->reglock, flags);
+}
+
+static int alchemy_clk_csrc_setp(struct clk_hw *hw, u8 index)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long flags;
+
+	spin_lock_irqsave(c->reglock, flags);
+	c->parent = index + 1;	/* value to write to register */
+	if (c->isen)
+		__alchemy_clk_csrc_en(c);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static u8 alchemy_clk_csrc_getp(struct clk_hw *hw)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+
+	return c->parent - 1;
+}
+
+static unsigned long alchemy_clk_csrc_recalc(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long v = (alchemy_rdsys(c->reg) >> c->shift) & 3;
+
+	return parent_rate / c->dt[v];
+}
+
+static int alchemy_clk_csrc_setr(struct clk_hw *hw, unsigned long rate,
+				 unsigned long parent_rate)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	unsigned long d, v, flags;
+	int i;
+
+	if (!rate || !parent_rate || rate > parent_rate)
+		return -EINVAL;
+
+	d = (parent_rate + (rate / 2)) / rate;
+	if (d > 4)
+		return -EINVAL;
+	if ((d == 3) && (c->dt[2] != 3))
+		d = 4;
+
+	for (i = 0; i < 4; i++)
+		if (c->dt[i] == d)
+			break;
+
+	if (i >= 4)
+		return -EINVAL;	/* oops */
+
+	spin_lock_irqsave(c->reglock, flags);
+	v = alchemy_rdsys(c->reg);
+	v &= ~(3 << c->shift);
+	v |= (i & 3) << c->shift;
+	alchemy_wrsys(v, c->reg);
+	spin_unlock_irqrestore(c->reglock, flags);
+
+	return 0;
+}
+
+static long alchemy_clk_csrc_detr(struct clk_hw *hw, unsigned long rate,
+					unsigned long *best_parent_rate,
+					struct clk **best_parent_clk)
+{
+	struct alchemy_fgcs_clk *c = to_fgcs_clk(hw);
+	int scale = c->dt[2] == 3 ? 1 : 2; /* au1300 check */
+
+	return alchemy_clk_fgcs_detr(hw, rate, best_parent_rate,
+				     best_parent_clk, scale, 4);
+}
+
+static struct clk_ops alchemy_clkops_csrc = {
+	.recalc_rate	= alchemy_clk_csrc_recalc,
+	.determine_rate	= alchemy_clk_csrc_detr,
+	.set_rate	= alchemy_clk_csrc_setr,
+	.set_parent	= alchemy_clk_csrc_setp,
+	.get_parent	= alchemy_clk_csrc_getp,
+	.enable		= alchemy_clk_csrc_en,
+	.disable	= alchemy_clk_csrc_dis,
+	.is_enabled	= alchemy_clk_csrc_isen,
+};
+
+static const char * const alchemy_clk_csrc_parents[] = {
+	/* disabled at index 0 */ ALCHEMY_AUXPLL_CLK,
+	ALCHEMY_FG0_CLK, ALCHEMY_FG1_CLK, ALCHEMY_FG2_CLK,
+	ALCHEMY_FG3_CLK, ALCHEMY_FG4_CLK, ALCHEMY_FG5_CLK
+};
+
+/* divider tables */
+static int alchemy_csrc_dt1[] = { 1, 4, 1, 2 };	/* rest */
+static int alchemy_csrc_dt2[] = { 1, 4, 3, 2 };	/* Au1300 */
+
+static int __init alchemy_clk_setup_imux(int ctype)
+{
+	struct alchemy_fgcs_clk *a;
+	const char * const *names;
+	struct clk_init_data id;
+	unsigned long v;
+	int i, ret, *dt;
+	struct clk *c;
+
+	id.ops = &alchemy_clkops_csrc;
+	id.parent_names = (const char **)alchemy_clk_csrc_parents;
+	id.num_parents = 7;
+	id.flags = CLK_SET_RATE_PARENT | CLK_GET_RATE_NOCACHE |
+		   CLK_IGNORE_UNUSED;
+
+	dt = alchemy_csrc_dt1;
+	switch (ctype) {
+	case ALCHEMY_CPU_AU1000:
+		names = alchemy_au1000_intclknames;
+		break;
+	case ALCHEMY_CPU_AU1500:
+		names = alchemy_au1500_intclknames;
+		break;
+	case ALCHEMY_CPU_AU1100:
+		names = alchemy_au1100_intclknames;
+		break;
+	case ALCHEMY_CPU_AU1550:
+		names = alchemy_au1550_intclknames;
+		break;
+	case ALCHEMY_CPU_AU1200:
+		names = alchemy_au1200_intclknames;
+		break;
+	case ALCHEMY_CPU_AU1300:
+		dt = alchemy_csrc_dt2;
+		names = alchemy_au1300_intclknames;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	a = kzalloc((sizeof(*a)) * 6, GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	spin_lock_init(&alchemy_clk_csrc_lock);
+	ret = 0;
+
+	for (i = 0; i < 6; i++) {
+		id.name = names[i];
+		if (!id.name)
+			goto next;
+
+		a->shift = i * 5;
+		a->reg = AU1000_SYS_CLKSRC;
+		a->reglock = &alchemy_clk_csrc_lock;
+		a->dt = dt;
+
+		/* default to first parent clock if mux is initially
+		 * set to disabled state.
+		 */
+		v = alchemy_rdsys(a->reg);
+		a->parent = ((v >> a->shift) >> 2) & 7;
+		if (!a->parent) {
+			a->parent = 1;
+			a->isen = 0;
+		} else
+			a->isen = 1;
+
+		a->hw.init = &id;
+		c = clk_register(NULL, &a->hw);
+		if (IS_ERR(c))
+			ret++;
+		else
+			clk_register_clkdev(c, id.name, NULL);
+next:
+		a++;
+	}
+
+	return ret;
+}
+
+
+/**********************************************************************/
+
+
+#define ERRCK(x)						\
+	if (IS_ERR(x)) {					\
+		ret = PTR_ERR(x);				\
+		goto out;					\
+	}
+
+static int __init alchemy_clk_init(void)
+{
+	int ctype = alchemy_get_cputype(), ret, i;
+	struct clk_aliastable *t = alchemy_clk_aliases;
+	struct clk *c;
+
+	/* Root of the Alchemy clock tree: external 12MHz crystal osc */
+	c = clk_register_fixed_rate(NULL, ALCHEMY_ROOT_CLK, NULL,
+					   CLK_IS_ROOT,
+					   ALCHEMY_ROOTCLK_RATE);
+	ERRCK(c)
+
+	/* CPU core clock */
+	c = alchemy_clk_setup_cpu(ALCHEMY_ROOT_CLK, ctype);
+	ERRCK(c)
+
+	/* AUXPLLs: max 1GHz on Au1300, 748MHz on older models */
+	i = (ctype == ALCHEMY_CPU_AU1300) ? 84 : 63;
+	c = alchemy_clk_setup_aux(ALCHEMY_ROOT_CLK, ALCHEMY_AUXPLL_CLK,
+				  i, AU1000_SYS_AUXPLL);
+	ERRCK(c)
+
+	if (ctype == ALCHEMY_CPU_AU1300) {
+		c = alchemy_clk_setup_aux(ALCHEMY_ROOT_CLK,
+					  ALCHEMY_AUXPLL2_CLK, i,
+					  AU1300_SYS_AUXPLL2);
+		ERRCK(c)
+	}
+
+	/* sysbus clock: cpu core clock divided by 2, 3 or 4 */
+	c = alchemy_clk_setup_sysbus(ALCHEMY_CPU_CLK);
+	ERRCK(c)
+
+	/* peripheral clock: runs at half rate of sysbus clk */
+	c = alchemy_clk_setup_periph(ALCHEMY_SYSBUS_CLK);
+	ERRCK(c)
+
+	/* SDR/DDR memory clock */
+	c = alchemy_clk_setup_mem(ALCHEMY_SYSBUS_CLK, ctype);
+	ERRCK(c)
+
+	/* L/RCLK: external static bus clock for synchronous mode */
+	c = alchemy_clk_setup_lrclk(ALCHEMY_PERIPH_CLK);
+	ERRCK(c)
+
+	/* Frequency dividers 0-5 */
+	ret = alchemy_clk_init_fgens(ctype);
+	if (ret) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	/* diving muxes for internal sources */
+	ret = alchemy_clk_setup_imux(ctype);
+	if (ret) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	/* set up aliases drivers might look for */
+	while (t->base) {
+		if (t->cputype == ctype)
+			clk_add_alias(t->alias, NULL, t->base, NULL);
+		t++;
+	}
+
+	pr_info("Alchemy clocktree installed\n");
+	return 0;
+
+out:
+	return ret;
+}
+postcore_initcall(alchemy_clk_init);