powerpc/mpc5121: Add clock driver

Plugs into the generic powerpc clock driver in
arch/powerpc/kernel/clock.c

The following subset of clk_interface is implemented:
    clk_get, clk_put:  get clock via name, release clock
    clk_enable, clk_disable:  enable or disable clock
    clk_get_rate:  get clock rate in Hz
    clk_set_rate:  stubbed
    clk_round_rate:  stubbed
    clk_set_parent: NULL
    clk_get_parent: NULL
Signed-off-by: NJohn Rigby <jrigby@freescale.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Makefile

+FRED=42
 VERSION = 2
 PATCHLEVEL = 6
 SUBLEVEL = 26

arch/powerpc/platforms/512x/Kconfig

@@ -2,6 +2,7 @@ config PPC_MPC512x
 	bool
 	select FSL_SOC
 	select IPIC
+	select PPC_CLOCK
 	default n
 
 config PPC_MPC5121

arch/powerpc/platforms/512x/Makefile

 #
 # Makefile for the Freescale PowerPC 512x linux kernel.
 #
+obj-y				+= clock.o
 obj-$(CONFIG_MPC5121_ADS)	+= mpc5121_ads.o

arch/powerpc/platforms/512x/clock.c

+/*
+ * Copyright (C) 2007,2008 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * Author: John Rigby <jrigby@freescale.com>
+ *
+ * Implements the clk api defined in include/linux/clk.h
+ *
+ *    Original based on linux/arch/arm/mach-integrator/clock.c
+ *
+ *    Copyright (C) 2004 ARM Limited.
+ *    Written by Deep Blue Solutions Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/clk.h>
+#include <linux/mutex.h>
+#include <linux/io.h>
+
+#include <linux/of_platform.h>
+#include <asm/mpc512x.h>
+#include <asm/clk_interface.h>
+
+#undef CLK_DEBUG
+
+static int clocks_initialized;
+
+#define CLK_HAS_RATE	0x1	/* has rate in MHz */
+#define CLK_HAS_CTRL	0x2	/* has control reg and bit */
+
+struct clk {
+	struct list_head node;
+	char name[32];
+	int flags;
+	struct device *dev;
+	unsigned long rate;
+	struct module *owner;
+	void (*calc) (struct clk *);
+	struct clk *parent;
+	int reg, bit;		/* CLK_HAS_CTRL */
+	int div_shift;		/* only used by generic_div_clk_calc */
+};
+
+static LIST_HEAD(clocks);
+static DEFINE_MUTEX(clocks_mutex);
+
+static struct clk *mpc5121_clk_get(struct device *dev, const char *id)
+{
+	struct clk *p, *clk = ERR_PTR(-ENOENT);
+	int dev_match = 0;
+	int id_match = 0;
+
+	if (dev == NULL && id == NULL)
+		return NULL;
+
+	mutex_lock(&clocks_mutex);
+	list_for_each_entry(p, &clocks, node) {
+		if (dev && dev == p->dev)
+			dev_match++;
+		if (strcmp(id, p->name) == 0)
+			id_match++;
+		if ((dev_match || id_match) && try_module_get(p->owner)) {
+			clk = p;
+			break;
+		}
+	}
+	mutex_unlock(&clocks_mutex);
+
+	return clk;
+}
+
+#ifdef CLK_DEBUG
+static void dump_clocks(void)
+{
+	struct clk *p;
+
+	mutex_lock(&clocks_mutex);
+	printk(KERN_INFO "CLOCKS:\n");
+	list_for_each_entry(p, &clocks, node) {
+		printk(KERN_INFO "  %s %ld", p->name, p->rate);
+		if (p->parent)
+			printk(KERN_INFO " %s %ld", p->parent->name,
+			       p->parent->rate);
+		if (p->flags & CLK_HAS_CTRL)
+			printk(KERN_INFO " reg/bit %d/%d", p->reg, p->bit);
+		printk("\n");
+	}
+	mutex_unlock(&clocks_mutex);
+}
+#define	DEBUG_CLK_DUMP() dump_clocks()
+#else
+#define	DEBUG_CLK_DUMP()
+#endif
+
+
+static void mpc5121_clk_put(struct clk *clk)
+{
+	module_put(clk->owner);
+}
+
+#define NRPSC 12
+
+struct mpc512x_clockctl {
+	u32 spmr;		/* System PLL Mode Reg */
+	u32 sccr[2];		/* System Clk Ctrl Reg 1 & 2 */
+	u32 scfr1;		/* System Clk Freq Reg 1 */
+	u32 scfr2;		/* System Clk Freq Reg 2 */
+	u32 reserved;
+	u32 bcr;		/* Bread Crumb Reg */
+	u32 pccr[NRPSC];	/* PSC Clk Ctrl Reg 0-11 */
+	u32 spccr;		/* SPDIF Clk Ctrl Reg */
+	u32 cccr;		/* CFM Clk Ctrl Reg */
+	u32 dccr;		/* DIU Clk Cnfg Reg */
+};
+
+struct mpc512x_clockctl __iomem *clockctl;
+
+static int mpc5121_clk_enable(struct clk *clk)
+{
+	unsigned int mask;
+
+	if (clk->flags & CLK_HAS_CTRL) {
+		mask = in_be32(&clockctl->sccr[clk->reg]);
+		mask |= 1 << clk->bit;
+		out_be32(&clockctl->sccr[clk->reg], mask);
+	}
+	return 0;
+}
+
+static void mpc5121_clk_disable(struct clk *clk)
+{
+	unsigned int mask;
+
+	if (clk->flags & CLK_HAS_CTRL) {
+		mask = in_be32(&clockctl->sccr[clk->reg]);
+		mask &= ~(1 << clk->bit);
+		out_be32(&clockctl->sccr[clk->reg], mask);
+	}
+}
+
+static unsigned long mpc5121_clk_get_rate(struct clk *clk)
+{
+	if (clk->flags & CLK_HAS_RATE)
+		return clk->rate;
+	else
+		return 0;
+}
+
+static long mpc5121_clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	return rate;
+}
+
+static int mpc5121_clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	return 0;
+}
+
+static int clk_register(struct clk *clk)
+{
+	mutex_lock(&clocks_mutex);
+	list_add(&clk->node, &clocks);
+	mutex_unlock(&clocks_mutex);
+	return 0;
+}
+
+static unsigned long spmf_mult(void)
+{
+	/*
+	 * Convert spmf to multiplier
+	 */
+	static int spmf_to_mult[] = {
+		68, 1, 12, 16,
+		20, 24, 28, 32,
+		36, 40, 44, 48,
+		52, 56, 60, 64
+	};
+	int spmf = (clockctl->spmr >> 24) & 0xf;
+	return spmf_to_mult[spmf];
+}
+
+static unsigned long sysdiv_div_x_2(void)
+{
+	/*
+	 * Convert sysdiv to divisor x 2
+	 * Some divisors have fractional parts so
+	 * multiply by 2 then divide by this value
+	 */
+	static int sysdiv_to_div_x_2[] = {
+		4, 5, 6, 7,
+		8, 9, 10, 14,
+		12, 16, 18, 22,
+		20, 24, 26, 30,
+		28, 32, 34, 38,
+		36, 40, 42, 46,
+		44, 48, 50, 54,
+		52, 56, 58, 62,
+		60, 64, 66,
+	};
+	int sysdiv = (clockctl->scfr2 >> 26) & 0x3f;
+	return sysdiv_to_div_x_2[sysdiv];
+}
+
+static unsigned long ref_to_sys(unsigned long rate)
+{
+	rate *= spmf_mult();
+	rate *= 2;
+	rate /= sysdiv_div_x_2();
+
+	return rate;
+}
+
+static unsigned long sys_to_ref(unsigned long rate)
+{
+	rate *= sysdiv_div_x_2();
+	rate /= 2;
+	rate /= spmf_mult();
+
+	return rate;
+}
+
+static long ips_to_ref(unsigned long rate)
+{
+	int ips_div = (clockctl->scfr1 >> 23) & 0x7;
+
+	rate *= ips_div;	/* csb_clk = ips_clk * ips_div */
+	rate *= 2;		/* sys_clk = csb_clk * 2 */
+	return sys_to_ref(rate);
+}
+
+static unsigned long devtree_getfreq(char *clockname)
+{
+	struct device_node *np;
+	const unsigned int *prop;
+	unsigned int val = 0;
+
+	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-immr");
+	if (np) {
+		prop = of_get_property(np, clockname, NULL);
+		if (prop)
+			val = *prop;
+	    of_node_put(np);
+	}
+	return val;
+}
+
+static void ref_clk_calc(struct clk *clk)
+{
+	unsigned long rate;
+
+	rate = devtree_getfreq("bus-frequency");
+	if (rate == 0) {
+		printk(KERN_ERR "No bus-frequency in dev tree\n");
+		clk->rate = 0;
+		return;
+	}
+	clk->rate = ips_to_ref(rate);
+}
+
+static struct clk ref_clk = {
+	.name = "ref_clk",
+	.calc = ref_clk_calc,
+};
+
+
+static void sys_clk_calc(struct clk *clk)
+{
+	clk->rate = ref_to_sys(ref_clk.rate);
+}
+
+static struct clk sys_clk = {
+	.name = "sys_clk",
+	.calc = sys_clk_calc,
+};
+
+static void diu_clk_calc(struct clk *clk)
+{
+	int diudiv_x_2 = clockctl->scfr1 & 0xff;
+	unsigned long rate;
+
+	rate = sys_clk.rate;
+
+	rate *= 2;
+	rate /= diudiv_x_2;
+
+	clk->rate = rate;
+}
+
+static void half_clk_calc(struct clk *clk)
+{
+	clk->rate = clk->parent->rate / 2;
+}
+
+static void generic_div_clk_calc(struct clk *clk)
+{
+	int div = (clockctl->scfr1 >> clk->div_shift) & 0x7;
+
+	clk->rate = clk->parent->rate / div;
+}
+
+static void unity_clk_calc(struct clk *clk)
+{
+	clk->rate = clk->parent->rate;
+}
+
+static struct clk csb_clk = {
+	.name = "csb_clk",
+	.calc = half_clk_calc,
+	.parent = &sys_clk,
+};
+
+static void e300_clk_calc(struct clk *clk)
+{
+	int spmf = (clockctl->spmr >> 16) & 0xf;
+	int ratex2 = clk->parent->rate * spmf;
+
+	clk->rate = ratex2 / 2;
+}
+
+static struct clk e300_clk = {
+	.name = "e300_clk",
+	.calc = e300_clk_calc,
+	.parent = &csb_clk,
+};
+
+static struct clk ips_clk = {
+	.name = "ips_clk",
+	.calc = generic_div_clk_calc,
+	.parent = &csb_clk,
+	.div_shift = 23,
+};
+
+/*
+ * Clocks controlled by SCCR1 (.reg = 0)
+ */
+static struct clk lpc_clk = {
+	.name = "lpc_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 0,
+	.bit = 30,
+	.calc = generic_div_clk_calc,
+	.parent = &ips_clk,
+	.div_shift = 11,
+};
+
+static struct clk nfc_clk = {
+	.name = "nfc_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 0,
+	.bit = 29,
+	.calc = generic_div_clk_calc,
+	.parent = &ips_clk,
+	.div_shift = 8,
+};
+
+static struct clk pata_clk = {
+	.name = "pata_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 0,
+	.bit = 28,
+	.calc = unity_clk_calc,
+	.parent = &ips_clk,
+};
+
+/*
+ * PSC clocks (bits 27 - 16)
+ * are setup elsewhere
+ */
+
+static struct clk sata_clk = {
+	.name = "sata_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 0,
+	.bit = 14,
+	.calc = unity_clk_calc,
+	.parent = &ips_clk,
+};
+
+static struct clk fec_clk = {
+	.name = "fec_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 0,
+	.bit = 13,
+	.calc = unity_clk_calc,
+	.parent = &ips_clk,
+};
+
+static struct clk pci_clk = {
+	.name = "pci_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 0,
+	.bit = 11,
+	.calc = generic_div_clk_calc,
+	.parent = &csb_clk,
+	.div_shift = 20,
+};
+
+/*
+ * Clocks controlled by SCCR2 (.reg = 1)
+ */
+static struct clk diu_clk = {
+	.name = "diu_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 31,
+	.calc = diu_clk_calc,
+};
+
+static struct clk axe_clk = {
+	.name = "axe_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 30,
+	.calc = unity_clk_calc,
+	.parent = &csb_clk,
+};
+
+static struct clk usb1_clk = {
+	.name = "usb1_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 28,
+	.calc = unity_clk_calc,
+	.parent = &csb_clk,
+};
+
+static struct clk usb2_clk = {
+	.name = "usb2_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 27,
+	.calc = unity_clk_calc,
+	.parent = &csb_clk,
+};
+
+static struct clk i2c_clk = {
+	.name = "i2c_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 26,
+	.calc = unity_clk_calc,
+	.parent = &ips_clk,
+};
+
+static struct clk mscan_clk = {
+	.name = "mscan_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 25,
+	.calc = unity_clk_calc,
+	.parent = &ips_clk,
+};
+
+static struct clk sdhc_clk = {
+	.name = "sdhc_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 24,
+	.calc = unity_clk_calc,
+	.parent = &ips_clk,
+};
+
+static struct clk mbx_bus_clk = {
+	.name = "mbx_bus_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 22,
+	.calc = half_clk_calc,
+	.parent = &csb_clk,
+};
+
+static struct clk mbx_clk = {
+	.name = "mbx_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 21,
+	.calc = unity_clk_calc,
+	.parent = &csb_clk,
+};
+
+static struct clk mbx_3d_clk = {
+	.name = "mbx_3d_clk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 20,
+	.calc = generic_div_clk_calc,
+	.parent = &mbx_bus_clk,
+	.div_shift = 14,
+};
+
+static void psc_mclk_in_calc(struct clk *clk)
+{
+	clk->rate = devtree_getfreq("psc_mclk_in");
+	if (!clk->rate)
+		clk->rate = 25000000;
+}
+
+static struct clk psc_mclk_in = {
+	.name = "psc_mclk_in",
+	.calc = psc_mclk_in_calc,
+};
+
+static struct clk spdif_txclk = {
+	.name = "spdif_txclk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 23,
+};
+
+static struct clk spdif_rxclk = {
+	.name = "spdif_rxclk",
+	.flags = CLK_HAS_CTRL,
+	.reg = 1,
+	.bit = 23,
+};
+
+static void ac97_clk_calc(struct clk *clk)
+{
+	/* ac97 bit clock is always 24.567 MHz */
+	clk->rate = 24567000;
+}
+
+static struct clk ac97_clk = {
+	.name = "ac97_clk_in",
+	.calc = ac97_clk_calc,
+};
+
+struct clk *rate_clks[] = {
+	&ref_clk,
+	&sys_clk,
+	&diu_clk,
+	&csb_clk,
+	&e300_clk,
+	&ips_clk,
+	&fec_clk,
+	&sata_clk,
+	&pata_clk,
+	&nfc_clk,
+	&lpc_clk,
+	&mbx_bus_clk,
+	&mbx_clk,
+	&mbx_3d_clk,
+	&axe_clk,
+	&usb1_clk,
+	&usb2_clk,
+	&i2c_clk,
+	&mscan_clk,
+	&sdhc_clk,
+	&pci_clk,
+	&psc_mclk_in,
+	&spdif_txclk,
+	&spdif_rxclk,
+	&ac97_clk,
+	NULL
+};
+
+static void rate_clk_init(struct clk *clk)
+{
+	if (clk->calc) {
+		clk->calc(clk);
+		clk->flags |= CLK_HAS_RATE;
+		clk_register(clk);
+	} else {
+		printk(KERN_WARNING
+		       "Could not initialize clk %s without a calc routine\n",
+		       clk->name);
+	}
+}
+
+static void rate_clks_init(void)
+{
+	struct clk **cpp, *clk;
+
+	cpp = rate_clks;
+	while ((clk = *cpp++))
+		rate_clk_init(clk);
+}
+
+/*
+ * There are two clk enable registers with 32 enable bits each
+ * psc clocks and device clocks are all stored in dev_clks
+ */
+struct clk dev_clks[2][32];
+
+/*
+ * Given a psc number return the dev_clk
+ * associated with it
+ */
+static struct clk *psc_dev_clk(int pscnum)
+{
+	int reg, bit;
+	struct clk *clk;
+
+	reg = 0;
+	bit = 27 - pscnum;
+
+	clk = &dev_clks[reg][bit];
+	clk->reg = 0;
+	clk->bit = bit;
+	return clk;
+}
+
+/*
+ * PSC clock rate calculation
+ */
+static void psc_calc_rate(struct clk *clk, int pscnum, struct device_node *np)
+{
+	unsigned long mclk_src = sys_clk.rate;
+	unsigned long mclk_div;
+
+	/*
+	 * Can only change value of mclk divider
+	 * when the divider is disabled.
+	 *
+	 * Zero is not a valid divider so minimum
+	 * divider is 1
+	 *
+	 * disable/set divider/enable
+	 */
+	out_be32(&clockctl->pccr[pscnum], 0);
+	out_be32(&clockctl->pccr[pscnum], 0x00020000);
+	out_be32(&clockctl->pccr[pscnum], 0x00030000);
+
+	if (clockctl->pccr[pscnum] & 0x80) {
+		clk->rate = spdif_rxclk.rate;
+		return;
+	}
+
+	switch ((clockctl->pccr[pscnum] >> 14) & 0x3) {
+	case 0:
+		mclk_src = sys_clk.rate;
+		break;
+	case 1:
+		mclk_src = ref_clk.rate;
+		break;
+	case 2:
+		mclk_src = psc_mclk_in.rate;
+		break;
+	case 3:
+		mclk_src = spdif_txclk.rate;
+		break;
+	}
+
+	mclk_div = ((clockctl->pccr[pscnum] >> 17) & 0x7fff) + 1;
+	clk->rate = mclk_src / mclk_div;
+}
+
+/*
+ * Find all psc nodes in device tree and assign a clock
+ * with name "psc%d_mclk" and dev pointing at the device
+ * returned from of_find_device_by_node
+ */
+static void psc_clks_init(void)
+{
+	struct device_node *np;
+	const u32 *cell_index;
+	struct of_device *ofdev;
+
+	for_each_compatible_node(np, NULL, "fsl,mpc5121-psc") {
+		cell_index = of_get_property(np, "cell-index", NULL);
+		if (cell_index) {
+			int pscnum = *cell_index;
+			struct clk *clk = psc_dev_clk(pscnum);
+
+			clk->flags = CLK_HAS_RATE | CLK_HAS_CTRL;
+			ofdev = of_find_device_by_node(np);
+			clk->dev = &ofdev->dev;
+			/*
+			 * AC97 is special rate clock does
+			 * not go through normal path
+			 */
+			if (strcmp("ac97", np->name) == 0)
+				clk->rate = ac97_clk.rate;
+			else
+				psc_calc_rate(clk, pscnum, np);
+			sprintf(clk->name, "psc%d_mclk", pscnum);
+			clk_register(clk);
+			clk_enable(clk);
+		}
+	}
+}
+
+static struct clk_interface mpc5121_clk_functions = {
+	.clk_get		= mpc5121_clk_get,
+	.clk_enable		= mpc5121_clk_enable,
+	.clk_disable		= mpc5121_clk_disable,
+	.clk_get_rate		= mpc5121_clk_get_rate,
+	.clk_put		= mpc5121_clk_put,
+	.clk_round_rate		= mpc5121_clk_round_rate,
+	.clk_set_rate		= mpc5121_clk_set_rate,
+	.clk_set_parent		= NULL,
+	.clk_get_parent		= NULL,
+};
+
+static int
+mpc5121_clk_init(void)
+{
+	struct device_node *np;
+
+	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-clock");
+	if (np) {
+		clockctl = of_iomap(np, 0);
+		of_node_put(np);
+	}
+
+	if (!clockctl) {
+		printk(KERN_ERR "Could not map clock control registers\n");
+		return 0;
+	}
+
+	rate_clks_init();
+	psc_clks_init();
+
+	/* leave clockctl mapped forever */
+	/*iounmap(clockctl); */
+	DEBUG_CLK_DUMP();
+	clocks_initialized++;
+	clk_functions = mpc5121_clk_functions;
+	return 0;
+}
+
+
+arch_initcall(mpc5121_clk_init);