diff options
Diffstat (limited to 'arch/arm/mach-stmp3xxx/dma.c')
| -rw-r--r-- | arch/arm/mach-stmp3xxx/dma.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/arch/arm/mach-stmp3xxx/dma.c b/arch/arm/mach-stmp3xxx/dma.c new file mode 100644 index 000000000000..49ed790b92d3 --- /dev/null +++ b/arch/arm/mach-stmp3xxx/dma.c @@ -0,0 +1,509 @@ +/* + * DMA helper routines for Freescale STMP37XX/STMP378X + * + * Author: dmitry pervushin <dimka@embeddedalley.com> + * + * Copyright 2008-2009 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; + 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, 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 = 0; + descriptor->handle = 0; + descriptor->virtual_buf_ptr = 0; + descriptor->next_descr = 0; + + 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 stmp37cc_dma_print_chain(struct stmp37xx_circ_dma_chain *chain) +{ + int i; + struct stmp3xxx_dma_descriptor *d; + + for (i = 0; i < chain->total_count; i++) { + d = &chain->chain[i]; + printk(KERN_DEBUG"Chain item %d (%p), command = %p(%x)\n" + "...next = %x" + "...cmd = %x" + "...buf_ptr/alt = %x\n", + i, d, d->command, d->handle, + d->command->next, d->command->cmd, + d->command->alternate); + } +} + +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 */ + + +static struct sysdev_class stmp3xxx_dma_sysclass = { + .name = "stmp3xxx-dma", +#ifdef CONFIG_PM + .suspend = NULL, + .resume = NULL, +#endif +}; + +static struct sys_device stmp3xxx_dma_device = { + .id = -1, + .cls = &stmp3xxx_dma_sysclass, +}; + +static ssize_t stmp3xxx_dma_list(struct sys_device *dev, + struct sysdev_attribute *attr, char *buf) +{ + int i, n = 0; + + for (i = 0; i < MAX_DMA_CHANNELS; i++) + if (IS_USED(i)) + n += sprintf(buf + n, "%d @ %s\t%s\n", + dmach(i), dmabus(i) == 0 ? "APBH" : "APBX", + channels[i].name ? channels[i].name : "unknown"); + return n; +} +SYSDEV_ATTR(channels, 0444, stmp3xxx_dma_list, NULL); + +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); + sysdev_class_register(&stmp3xxx_dma_sysclass); + sysdev_register(&stmp3xxx_dma_device); + sysdev_create_file(&stmp3xxx_dma_device, &attr_channels); + +#ifdef CONFIG_CPU_FREQ + cpufreq_register_notifier(&dma_cpufreq_nb.nb, + CPUFREQ_TRANSITION_NOTIFIER); +#endif /* CONFIG_CPU_FREQ */ + +} |