[PATCH 0/2] mpc52xx: stop drivers from accessing clock config directly

@@ -180,6 +180,8 @@ static void __init efika_setup_arch(void)
 {
 	rtas_initialize();
 
+	mpc52xx_setup_clocks();
+
 	efika_pcisetup();
 
 #ifdef CONFIG_PM

@@ -143,6 +143,7 @@ static void __init lite5200_setup_arch(void)
 	lite5200_fix_port_config();
 
 	/* Some mpc5200 & mpc5200b related configuration */
+	mpc5200_setup_clocks();
 	mpc5200_setup_xlb_arbiter();
 
 	/* Map wdt for mpc52xx_restart() */

@@ -14,6 +14,7 @@
 
 #include <linux/kernel.h>
 #include <linux/of_platform.h>
+#include <linux/spinlock.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/mpc52xx.h>

@@ -26,6 +27,20 @@
  */
 static volatile struct mpc52xx_gpt *mpc52xx_wdt = NULL;
 
+/*
+ * Location of clock distibution module.  The device regs are mapped at
+ * board init time to eliminate runtime lookups.  All access to these
+ * registers is protected with the mpc52xx_cdm_lock spinlock
+ */
+static void __iomem *mpc52xx_cdm_regs = NULL;
+static spinlock_t mpc52xx_cdm_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ * Cached clock values
+ */
+static unsigned int mpc52xx_system_freq;
+static unsigned int mpc52xx_ipb_freq;
+
 static void __iomem *
 mpc52xx_map_node(struct device_node *ofn)
 {

@@ -74,26 +89,92 @@ EXPORT_SYMBOL(mpc52xx_find_and_map_path);
 unsigned int
 mpc52xx_find_ipb_freq(struct device_node *node)
 {
-	struct device_node *np;
-	const unsigned int *p_ipb_freq = NULL;
+	return mpc52xx_ipb_freq;
+}
+EXPORT_SYMBOL(mpc52xx_find_ipb_freq);
 
-	of_node_get(node);
-	while (node) {
-		p_ipb_freq = of_get_property(node, "bus-frequency", NULL);
-		if (p_ipb_freq)
-			break;
+/*
+ * Clock support for PSCs
+ */
+struct mpc52xx_cdm_psc_clk_params {
+	int div_reg;
+	int enable;
+};
 
-		np = of_get_parent(node);
-		of_node_put(node);
-		node = np;
-	}
-	if (node)
-		of_node_put(node);
+static struct mpc52xx_cdm_psc_clk_params mpc52xx_cdm_psc_clk_params[] = {
+	[0] = { .div_reg = MPC52xx_CDM_MCLKEN_DIV_PSC1_OFF, .enable = 0x20 },
+	[1] = { .div_reg = MPC52xx_CDM_MCLKEN_DIV_PSC2_OFF, .enable = 0x40 },
+	[2] = { .div_reg = MPC52xx_CDM_MCLKEN_DIV_PSC3_OFF, .enable = 0x80 },
+	[5] = { .div_reg = MPC52xx_CDM_MCLKEN_DIV_PSC6_OFF, .enable = 0x10 },
+};
+
+/**
+ * mpc52xx_cdm_set_psc_clk: Set input MCLK for a PSC
+ * @psc: id of PSC, based at 0
+ * @freq_hz: desired frequency
+ */
+int mpc52xx_cdm_set_psc_clk(int psc, u32 freq_hz)
+{
+	struct mpc52xx_cdm_psc_clk_params *params;
+	unsigned long flags;
+	u16 mclken_div;
+	u32 reg;
+
+	if (!mpc52xx_cdm_regs)
+		return -ENODEV;
 
-	return p_ipb_freq ? *p_ipb_freq : 0;
+	/* Calculate the parameters */
+	params = &mpc52xx_cdm_psc_clk_params[psc];
+	mclken_div = 0x8000 | (((mpc52xx_system_freq / freq_hz) - 1) & 0x1FF);
+
+	spin_lock_irqsave(&mpc52xx_cdm_lock, flags);
+
+	/* disable the clock before modifying frequency */
+	reg = in_be32(mpc52xx_cdm_regs + MPC52xx_CDM_CLK_ENABLES_OFF);
+	reg &= ~params->enable;
+
+	/* Set the new speed */
+	out_be16(mpc52xx_cdm_regs + params->div_reg, mclken_div);
+
+	/* Set the enable bit */
+	reg |= params->enable;
+	out_be32(mpc52xx_cdm_regs + MPC52xx_CDM_CLK_ENABLES_OFF, reg);
+
+	spin_unlock_irqrestore(&mpc52xx_cdm_lock, flags);
+
+	return 0;
 }
-EXPORT_SYMBOL(mpc52xx_find_ipb_freq);
+EXPORT_SYMBOL_GPL(mpc52xx_cdm_set_psc_clk);
 
+/**
+ * mpc5200_setup_clocks: called by platform code to setup clock frequencies
+ */
+void mpc5200_setup_clocks(void)
+{
+	struct device_node *node;
+	const unsigned int *prop = NULL;
+
+	node = of_find_compatible_node(NULL, NULL, "fsl,mpc5200");
+	if (!node)
+		node = of_find_compatible_node(NULL, NULL, "mpc5200");
+	if (!node) {
+		printk(KERN_ERR"mpc5200_setup_clocks: could not find soc node\n");
+		return;
+	}
+
+	prop = of_get_property(node, "system-frequency", NULL);
+	if (prop)
+		mpc52xx_system_freq = *prop;
+	
+	prop = of_get_property(node, "bus-frequency", NULL);
+	if (prop)
+		mpc52xx_ipb_freq = *prop;
+	of_node_put(node);
+
+	mpc52xx_cdm_regs = mpc52xx_find_and_map("fsl,mpc5200-cdm");
+	if (!mpc52xx_cdm_regs)
+		mpc52xx_cdm_regs = mpc52xx_find_and_map("mpc5200-cdm");
+}
 
 /*
  * Configure the XLB arbiter settings to match what Linux expects.

@@ -176,3 +257,4 @@ mpc52xx_restart(char *cmd)
 
 	while (1);
 }
+

@@ -208,6 +208,7 @@ struct mpc52xx_cdm {
 	u16 fd_counters;	/* CDM + 0x12  reg4 byte2,3 */
 
 	u32 clk_enables;	/* CDM + 0x14  reg5 */
+#define MPC52xx_CDM_CLK_ENABLES_OFF	0x14
 
 	u8 osc_disable;		/* CDM + 0x18  reg6 byte0 */
 	u8 reserved0[3];	/* CDM + 0x19  reg6 byte1,2,3 */

@@ -228,15 +229,19 @@ struct mpc52xx_cdm {
 
 	u16 reserved4;		/* CDM + 0x28  reg10 byte0,1 */
 	u16 mclken_div_psc1;	/* CDM + 0x2a  reg10 byte2,3 */
+#define MPC52xx_CDM_MCLKEN_DIV_PSC1_OFF	0x2a
 
 	u16 reserved5;		/* CDM + 0x2c  reg11 byte0,1 */
 	u16 mclken_div_psc2;	/* CDM + 0x2e  reg11 byte2,3 */
+#define MPC52xx_CDM_MCLKEN_DIV_PSC2_OFF	0x2e
 
 	u16 reserved6;		/* CDM + 0x30  reg12 byte0,1 */
 	u16 mclken_div_psc3;	/* CDM + 0x32  reg12 byte2,3 */
+#define MPC52xx_CDM_MCLKEN_DIV_PSC3_OFF	0x32
 
 	u16 reserved7;		/* CDM + 0x34  reg13 byte0,1 */
 	u16 mclken_div_psc6;	/* CDM + 0x36  reg13 byte2,3 */
+#define MPC52xx_CDM_MCLKEN_DIV_PSC6_OFF	0x36
 };
 
 #endif /* __ASSEMBLY__ */

@@ -251,6 +256,8 @@ struct mpc52xx_cdm {
 extern void __iomem * mpc52xx_find_and_map(const char *);
 extern void __iomem * mpc52xx_find_and_map_path(const char *path);
 extern unsigned int mpc52xx_find_ipb_freq(struct device_node *node);
+extern int mpc52xx_cdm_set_psc_clk(int psc, u32 freq_hz);
+extern void mpc5200_setup_clocks(void);
 extern void mpc5200_setup_xlb_arbiter(void);
 extern void mpc52xx_declare_of_platform_devices(void);
 

@@ -328,77 +328,15 @@ static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
 	kfree(spi->controller_state);
 }
 
-static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
+static int mpc52xx_psc_spi_config(int psc_id, struct mpc52xx_psc_spi *mps)
 {
-	struct mpc52xx_cdm __iomem *cdm;
-	struct mpc52xx_gpio __iomem *gpio;
 	struct mpc52xx_psc __iomem *psc = mps->psc;
-	u32 ul;
-	u32 mclken_div;
-	int ret = 0;
+	int rc;
 
-#if defined(CONFIG_PPC_MERGE)
-	cdm = mpc52xx_find_and_map("mpc5200-cdm");
-	gpio = mpc52xx_find_and_map("mpc5200-gpio");
-#else
-	cdm = ioremap(MPC52xx_PA(MPC52xx_CDM_OFFSET), MPC52xx_CDM_SIZE);
-	gpio = ioremap(MPC52xx_PA(MPC52xx_GPIO_OFFSET), MPC52xx_GPIO_SIZE);
-#endif
-	if (!cdm || !gpio) {
-		printk(KERN_ERR "Error mapping CDM/GPIO\n");
-		ret = -EFAULT;
-		goto unmap_regs;
-	}
-
-	/* default sysclk is 512MHz */
-	mclken_div = 0x8000 |
-		(((mps->sysclk ? mps->sysclk : 512000000) / MCLK) & 0x1FF);
-
-	switch (psc_id) {
-	case 1:
-		ul = in_be32(&gpio->port_config);
-		ul &= 0xFFFFFFF8;
-		ul |= 0x00000006;
-		out_be32(&gpio->port_config, ul);
-		out_be16(&cdm->mclken_div_psc1, mclken_div);
-		ul = in_be32(&cdm->clk_enables);
-		ul |= 0x00000020;
-		out_be32(&cdm->clk_enables, ul);
-		break;
-	case 2:
-		ul = in_be32(&gpio->port_config);
-		ul &= 0xFFFFFF8F;
-		ul |= 0x00000060;
-		out_be32(&gpio->port_config, ul);
-		out_be16(&cdm->mclken_div_psc2, mclken_div);
-		ul = in_be32(&cdm->clk_enables);
-		ul |= 0x00000040;
-		out_be32(&cdm->clk_enables, ul);
-		break;
-	case 3:
-		ul = in_be32(&gpio->port_config);
-		ul &= 0xFFFFF0FF;
-		ul |= 0x00000600;
-		out_be32(&gpio->port_config, ul);
-		out_be16(&cdm->mclken_div_psc3, mclken_div);
-		ul = in_be32(&cdm->clk_enables);
-		ul |= 0x00000080;
-		out_be32(&cdm->clk_enables, ul);
-		break;
-	case 6:
-		ul = in_be32(&gpio->port_config);
-		ul &= 0xFF8FFFFF;
-		ul |= 0x00700000;
-		out_be32(&gpio->port_config, ul);
-		out_be16(&cdm->mclken_div_psc6, mclken_div);
-		ul = in_be32(&cdm->clk_enables);
-		ul |= 0x00000010;
-		out_be32(&cdm->clk_enables, ul);
-		break;
-	default:
-		ret = -EINVAL;
-		goto unmap_regs;
-	}
+	/* Setup a desirable MCLK */
+	rc = mpc52xx_cdm_set_psc_clk(psc_id, MCLK);
+	if (rc)
+		return rc;
 
 	/* Reset the PSC into a known state */
 	out_8(&psc->command, MPC52xx_PSC_RST_RX);

@@ -422,13 +360,7 @@ static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
 
 	mps->bits_per_word = 8;
 
-unmap_regs:
-	if (cdm)
-		iounmap(cdm);
-	if (gpio)
-		iounmap(gpio);
-
-	return ret;
+	return 0;
 }
 
 static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)

@@ -493,7 +425,7 @@ static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	if (ret)
 		goto free_master;
 
-	ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
+	ret = mpc52xx_psc_spi_config(master->bus_num-1, mps);
 	if (ret < 0)
 		goto free_irq;
 

@@ -180,7 +180,7 @@ static void __init efika_setup_arch(void
 {
 	rtas_initialize();
 
-	mpc52xx_setup_clocks();
+	mpc5200_setup_clocks();
 
 	efika_pcisetup();