[ARM] 5477/1: Freescale STMP platform support [6/10]

Sources: common STMP3xxx platform support

Signed-off-by: dmitry pervushin <dpervushin@embeddedalley.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 462 insertions, 0 deletions

diff --git a/arch/arm/plat-stmp3xxx/dma.c b/arch/arm/plat-stmp3xxx/dma.c
new file mode 100644
index 000000000000..cf42de05e568
--- /dev/null
+++ b/arch/arm/plat-stmp3xxx/dma.c
@@ -0,0 +1,462 @@
+/*
+ * DMA helper routines for Freescale STMP37XX/STMP378X
+ *
+ * Author: dmitry pervushin <dpervushin@embeddedalley.com>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/sysdev.h>
+#include <linux/cpufreq.h>
+
+#include <asm/page.h>
+
+#include <mach/dma.h>
+#include <mach/regs-apbx.h>
+#include <mach/regs-apbh.h>
+
+static const size_t pool_item_size = sizeof(struct stmp3xxx_dma_command);
+static const size_t pool_alignment = 8;
+static struct stmp3xxx_dma_user {
+	void *pool;
+	int inuse;
+	const char *name;
+} channels[MAX_DMA_CHANNELS];
+
+static inline int dmach(int ch)
+{
+	return ch % 16;
+}
+
+static inline int dmabus(int ch)
+{
+	return ch / 16;
+}
+
+#define IS_VALID_CHANNEL(ch) ((ch) >= 0 && (ch) < MAX_DMA_CHANNELS)
+#define IS_USED(ch) (channels[ch].inuse)
+
+int stmp3xxx_dma_request(int ch, struct device *dev, const char *name)
+{
+	struct stmp3xxx_dma_user *user;
+	int err = 0;
+
+	user = channels + ch;
+	if (!IS_VALID_CHANNEL(ch)) {
+		err = -ENODEV;
+		goto out;
+	}
+	if (IS_USED(ch)) {
+		err = -EBUSY;
+		goto out;
+	}
+	/* Create a pool to allocate dma commands from */
+	user->pool = dma_pool_create(name, dev, pool_item_size,
+				     pool_alignment, PAGE_SIZE);
+	if (user->pool == NULL) {
+		err = -ENOMEM;
+		goto out;
+	}
+	user->name = name;
+	user->inuse++;
+out:
+	return err;
+}
+EXPORT_SYMBOL(stmp3xxx_dma_request);
+
+int stmp3xxx_dma_release(int ch)
+{
+	struct stmp3xxx_dma_user *user = channels + ch;
+	int err = 0;
+
+	if (!IS_VALID_CHANNEL(ch)) {
+		err = -ENODEV;
+		goto out;
+	}
+	if (!IS_USED(ch)) {
+		err = -EBUSY;
+		goto out;
+	}
+	BUG_ON(user->pool == NULL);
+	dma_pool_destroy(user->pool);
+	user->inuse--;
+out:
+	return err;
+}
+EXPORT_SYMBOL(stmp3xxx_dma_release);
+
+int stmp3xxx_dma_read_semaphore(int channel)
+{
+	int sem = -1;
+
+	switch (dmabus(channel)) {
+	case STMP3XXX_BUS_APBH:
+		sem =
+		    (HW_APBH_CHn_SEMA_RD(dmach(channel)) &
+		     BM_APBH_CHn_SEMA_PHORE) >> BP_APBH_CHn_SEMA_PHORE;
+		break;
+
+	case STMP3XXX_BUS_APBX:
+		sem =
+		    (HW_APBX_CHn_SEMA_RD(dmach(channel)) &
+		     BM_APBX_CHn_SEMA_PHORE) >> BP_APBX_CHn_SEMA_PHORE;
+		break;
+	default:
+		BUG();
+	}
+	return sem;
+}
+EXPORT_SYMBOL(stmp3xxx_dma_read_semaphore);
+
+int stmp3xxx_dma_allocate_command(int channel,
+				  struct stmp3xxx_dma_descriptor *descriptor)
+{
+	struct stmp3xxx_dma_user *user = channels + channel;
+	int err = 0;
+
+	if (!IS_VALID_CHANNEL(channel)) {
+		err = -ENODEV;
+		goto out;
+	}
+	if (!IS_USED(channel)) {
+		err = -EBUSY;
+		goto out;
+	}
+	if (descriptor == NULL) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* Allocate memory for a command from the buffer */
+	descriptor->command =
+	    dma_pool_alloc(user->pool, GFP_KERNEL, &descriptor->handle);
+
+	/* Check it worked */
+	if (!descriptor->command) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	memset(descriptor->command, 0, pool_item_size);
+out:
+	WARN_ON(err);
+	return err;
+}
+EXPORT_SYMBOL(stmp3xxx_dma_allocate_command);
+
+int stmp3xxx_dma_free_command(int channel,
+			      struct stmp3xxx_dma_descriptor *descriptor)
+{
+	int err = 0;
+
+	if (!IS_VALID_CHANNEL(channel)) {
+		err = -ENODEV;
+		goto out;
+	}
+	if (!IS_USED(channel)) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	/* Return the command memory to the pool */
+	dma_pool_free(channels[channel].pool, descriptor->command,
+		      descriptor->handle);
+
+	/* Initialise descriptor so we're not tempted to use it */
+	descriptor->command = NULL;
+	descriptor->handle = 0;
+	descriptor->virtual_buf_ptr = NULL;
+	descriptor->next_descr = NULL;
+
+	WARN_ON(err);
+out:
+	return err;
+}
+EXPORT_SYMBOL(stmp3xxx_dma_free_command);
+
+void stmp3xxx_dma_go(int channel,
+		     struct stmp3xxx_dma_descriptor *head, u32 semaphore)
+{
+	int ch = dmach(channel);
+
+	switch (dmabus(channel)) {
+	case STMP3XXX_BUS_APBH:
+		/* Set next command */
+		HW_APBH_CHn_NXTCMDAR_WR(ch, head->handle);
+		/* Set counting semaphore (kicks off transfer). Assumes
+		   peripheral has been set up correctly */
+		HW_APBH_CHn_SEMA_WR(ch, semaphore);
+		break;
+
+	case STMP3XXX_BUS_APBX:
+		/* Set next command */
+		HW_APBX_CHn_NXTCMDAR_WR(ch, head->handle);
+		/* Set counting semaphore (kicks off transfer). Assumes
+		   peripheral has been set up correctly */
+		HW_APBX_CHn_SEMA_WR(ch, semaphore);
+		break;
+	}
+}
+EXPORT_SYMBOL(stmp3xxx_dma_go);
+
+int stmp3xxx_dma_running(int channel)
+{
+	switch (dmabus(channel)) {
+	case STMP3XXX_BUS_APBH:
+		return HW_APBH_CHn_SEMA_RD(dmach(channel)) &
+		    BM_APBH_CHn_SEMA_PHORE;
+
+	case STMP3XXX_BUS_APBX:
+		return HW_APBX_CHn_SEMA_RD(dmach(channel)) &
+		    BM_APBX_CHn_SEMA_PHORE;
+
+	default:
+		BUG();
+		return 0;
+	}
+}
+EXPORT_SYMBOL(stmp3xxx_dma_running);
+
+/*
+ * Circular dma chain management
+ */
+void stmp3xxx_dma_free_chain(struct stmp37xx_circ_dma_chain *chain)
+{
+	int i;
+
+	for (i = 0; i < chain->total_count; i++)
+		stmp3xxx_dma_free_command(
+			STMP3xxx_DMA(chain->channel, chain->bus),
+			&chain->chain[i]);
+}
+EXPORT_SYMBOL(stmp3xxx_dma_free_chain);
+
+int stmp3xxx_dma_make_chain(int ch, struct stmp37xx_circ_dma_chain *chain,
+			    struct stmp3xxx_dma_descriptor descriptors[],
+			    unsigned items)
+{
+	int i;
+	int err = 0;
+
+	if (items == 0)
+		return err;
+
+	for (i = 0; i < items; i++) {
+		err = stmp3xxx_dma_allocate_command(ch, &descriptors[i]);
+		if (err) {
+			WARN_ON(err);
+			/*
+			 * Couldn't allocate the whole chain.
+			 * deallocate what has been allocated
+			 */
+			if (i) {
+				do {
+					stmp3xxx_dma_free_command(ch,
+								  &descriptors
+								  [i]);
+				} while (i-- >= 0);
+			}
+			return err;
+		}
+
+		/* link them! */
+		if (i > 0) {
+			descriptors[i - 1].next_descr = &descriptors[i];
+			descriptors[i - 1].command->next =
+						descriptors[i].handle;
+		}
+	}
+
+	/* make list circular */
+	descriptors[items - 1].next_descr = &descriptors[0];
+	descriptors[items - 1].command->next = descriptors[0].handle;
+
+	chain->total_count = items;
+	chain->chain = descriptors;
+	chain->free_index = 0;
+	chain->active_index = 0;
+	chain->cooked_index = 0;
+	chain->free_count = items;
+	chain->active_count = 0;
+	chain->cooked_count = 0;
+	chain->bus = dmabus(ch);
+	chain->channel = dmach(ch);
+	return err;
+}
+EXPORT_SYMBOL(stmp3xxx_dma_make_chain);
+
+void stmp37xx_circ_clear_chain(struct stmp37xx_circ_dma_chain *chain)
+{
+	BUG_ON(stmp3xxx_dma_running(STMP3xxx_DMA(chain->channel, chain->bus)) >
+	       0);
+	chain->free_index = 0;
+	chain->active_index = 0;
+	chain->cooked_index = 0;
+	chain->free_count = chain->total_count;
+	chain->active_count = 0;
+	chain->cooked_count = 0;
+}
+EXPORT_SYMBOL(stmp37xx_circ_clear_chain);
+
+void stmp37xx_circ_advance_free(struct stmp37xx_circ_dma_chain *chain,
+		unsigned count)
+{
+	BUG_ON(chain->cooked_count < count);
+
+	chain->cooked_count -= count;
+	chain->cooked_index += count;
+	chain->cooked_index %= chain->total_count;
+	chain->free_count += count;
+}
+EXPORT_SYMBOL(stmp37xx_circ_advance_free);
+
+void stmp37xx_circ_advance_active(struct stmp37xx_circ_dma_chain *chain,
+		unsigned count)
+{
+	BUG_ON(chain->free_count < count);
+
+	chain->free_count -= count;
+	chain->free_index += count;
+	chain->free_index %= chain->total_count;
+	chain->active_count += count;
+
+	switch (chain->bus) {
+	case STMP3XXX_BUS_APBH:
+		/* Set counting semaphore (kicks off transfer). Assumes
+		   peripheral has been set up correctly */
+		HW_APBH_CHn_SEMA_CLR(chain->channel,
+				     BM_APBH_CHn_SEMA_INCREMENT_SEMA);
+		HW_APBH_CHn_SEMA_SET(chain->channel,
+				     BF_APBH_CHn_SEMA_INCREMENT_SEMA(count));
+		break;
+
+	case STMP3XXX_BUS_APBX:
+		/* Set counting semaphore (kicks off transfer). Assumes
+		   peripheral has been set up correctly */
+		HW_APBX_CHn_SEMA_CLR(chain->channel,
+				     BM_APBX_CHn_SEMA_INCREMENT_SEMA);
+		HW_APBX_CHn_SEMA_SET(chain->channel,
+				     BF_APBX_CHn_SEMA_INCREMENT_SEMA(count));
+		break;
+
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(stmp37xx_circ_advance_active);
+
+unsigned stmp37xx_circ_advance_cooked(struct stmp37xx_circ_dma_chain *chain)
+{
+	unsigned cooked;
+
+	cooked = chain->active_count -
+	  stmp3xxx_dma_read_semaphore(STMP3xxx_DMA(chain->channel, chain->bus));
+
+	chain->active_count -= cooked;
+	chain->active_index += cooked;
+	chain->active_index %= chain->total_count;
+
+	chain->cooked_count += cooked;
+
+	return cooked;
+}
+EXPORT_SYMBOL(stmp37xx_circ_advance_cooked);
+
+void stmp3xxx_dma_set_alt_target(int channel, int function)
+{
+#if defined(CONFIG_ARCH_STMP37XX)
+	unsigned bits = 4;
+#elif defined(CONFIG_ARCH_STMP378X)
+	unsigned bits = 2;
+#else
+#error wrong arch
+#endif
+	int shift = dmach(channel) * bits;
+	unsigned mask = (1<<bits) - 1;
+
+	BUG_ON(function < 0 || function >= (1<<bits));
+	pr_debug("%s: channel = %d, using mask %x, "
+		 "shift = %d\n", __func__, channel, mask, shift);
+
+	switch (dmabus(channel)) {
+	case STMP3XXX_BUS_APBH:
+		HW_APBH_DEVSEL_CLR(mask<<shift);
+		HW_APBH_DEVSEL_SET(function<<shift);
+		break;
+	case STMP3XXX_BUS_APBX:
+		HW_APBX_DEVSEL_CLR(mask<<shift);
+		HW_APBX_DEVSEL_SET(function<<shift);
+		break;
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(stmp3xxx_dma_set_alt_target);
+
+void stmp3xxx_dma_suspend(void)
+{
+	HW_APBH_CTRL0_SET(BM_APBH_CTRL0_CLKGATE);
+	HW_APBX_CTRL0_SET(BM_APBX_CTRL0_CLKGATE);
+}
+
+void stmp3xxx_dma_resume(void)
+{
+	HW_APBH_CTRL0_CLR(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST);
+	HW_APBX_CTRL0_CLR(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST);
+}
+
+#ifdef CONFIG_CPU_FREQ
+
+struct dma_notifier_block {
+	struct notifier_block nb;
+	void *data;
+};
+
+static int dma_cpufreq_notifier(struct notifier_block *self,
+				unsigned long phase, void *p)
+{
+	switch (phase) {
+	case CPUFREQ_POSTCHANGE:
+		stmp3xxx_dma_resume();
+		break;
+
+	case CPUFREQ_PRECHANGE:
+		stmp3xxx_dma_suspend();
+		break;
+
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct dma_notifier_block dma_cpufreq_nb = {
+	.nb = {
+		.notifier_call = dma_cpufreq_notifier,
+	},
+};
+#endif /* CONFIG_CPU_FREQ */
+
+void __init stmp3xxx_dma_init(void)
+{
+	HW_APBH_CTRL0_CLR(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST);
+	HW_APBX_CTRL0_CLR(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST);
+#ifdef CONFIG_CPU_FREQ
+	cpufreq_register_notifier(&dma_cpufreq_nb.nb,
+				CPUFREQ_TRANSITION_NOTIFIER);
+#endif /* CONFIG_CPU_FREQ */
+
+}