diff options
Diffstat (limited to 'arch/arm/plat-stmp3xxx/dma.c')
| -rw-r--r-- | arch/arm/plat-stmp3xxx/dma.c | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/arch/arm/plat-stmp3xxx/dma.c b/arch/arm/plat-stmp3xxx/dma.c new file mode 100644 index 0000000..d2f4977 --- /dev/null +++ b/arch/arm/plat-stmp3xxx/dma.c @@ -0,0 +1,463 @@ +/* + * 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/platform.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]; + +#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 (STMP3XXX_DMA_BUS(channel)) { + case STMP3XXX_BUS_APBH: + sem = __raw_readl(REGS_APBH_BASE + HW_APBH_CHn_SEMA + + STMP3XXX_DMA_CHANNEL(channel) * 0x70); + sem &= BM_APBH_CHn_SEMA_PHORE; + sem >>= BP_APBH_CHn_SEMA_PHORE; + break; + + case STMP3XXX_BUS_APBX: + sem = __raw_readl(REGS_APBX_BASE + HW_APBX_CHn_SEMA + + STMP3XXX_DMA_CHANNEL(channel) * 0x70); + sem &= BM_APBX_CHn_SEMA_PHORE; + sem >>= 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 = STMP3XXX_DMA_CHANNEL(channel); + void __iomem *c, *s; + + switch (STMP3XXX_DMA_BUS(channel)) { + case STMP3XXX_BUS_APBH: + c = REGS_APBH_BASE + HW_APBH_CHn_NXTCMDAR + 0x70 * ch; + s = REGS_APBH_BASE + HW_APBH_CHn_SEMA + 0x70 * ch; + break; + + case STMP3XXX_BUS_APBX: + c = REGS_APBX_BASE + HW_APBX_CHn_NXTCMDAR + 0x70 * ch; + s = REGS_APBX_BASE + HW_APBX_CHn_SEMA + 0x70 * ch; + break; + + default: + return; + } + + /* Set next command */ + __raw_writel(head->handle, c); + /* Set counting semaphore (kicks off transfer). Assumes + peripheral has been set up correctly */ + __raw_writel(semaphore, s); +} +EXPORT_SYMBOL(stmp3xxx_dma_go); + +int stmp3xxx_dma_running(int channel) +{ + switch (STMP3XXX_DMA_BUS(channel)) { + case STMP3XXX_BUS_APBH: + return (__raw_readl(REGS_APBH_BASE + HW_APBH_CHn_SEMA + + 0x70 * STMP3XXX_DMA_CHANNEL(channel))) & + BM_APBH_CHn_SEMA_PHORE; + + case STMP3XXX_BUS_APBX: + return (__raw_readl(REGS_APBX_BASE + HW_APBX_CHn_SEMA + + 0x70 * STMP3XXX_DMA_CHANNEL(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 = STMP3XXX_DMA_BUS(ch); + chain->channel = STMP3XXX_DMA_CHANNEL(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))); + 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) +{ + void __iomem *c; + u32 mask_clr, mask; + 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: + c = REGS_APBH_BASE + HW_APBH_CHn_SEMA + 0x70 * chain->channel; + mask_clr = BM_APBH_CHn_SEMA_INCREMENT_SEMA; + mask = BF(count, APBH_CHn_SEMA_INCREMENT_SEMA); + break; + case STMP3XXX_BUS_APBX: + c = REGS_APBX_BASE + HW_APBX_CHn_SEMA + 0x70 * chain->channel; + mask_clr = BM_APBX_CHn_SEMA_INCREMENT_SEMA; + mask = BF(count, APBX_CHn_SEMA_INCREMENT_SEMA); + break; + default: + BUG(); + return; + } + + /* Set counting semaphore (kicks off transfer). Assumes + peripheral has been set up correctly */ + stmp3xxx_clearl(mask_clr, c); + stmp3xxx_setl(mask, c); +} +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 = STMP3XXX_DMA_CHANNEL(channel) * bits; + unsigned mask = (1<<bits) - 1; + void __iomem *c; + + BUG_ON(function < 0 || function >= (1<<bits)); + pr_debug("%s: channel = %d, using mask %x, " + "shift = %d\n", __func__, channel, mask, shift); + + switch (STMP3XXX_DMA_BUS(channel)) { + case STMP3XXX_BUS_APBH: + c = REGS_APBH_BASE + HW_APBH_DEVSEL; + break; + case STMP3XXX_BUS_APBX: + c = REGS_APBX_BASE + HW_APBX_DEVSEL; + break; + default: + BUG(); + } + stmp3xxx_clearl(mask << shift, c); + stmp3xxx_setl(mask << shift, c); +} +EXPORT_SYMBOL(stmp3xxx_dma_set_alt_target); + +void stmp3xxx_dma_suspend(void) +{ + stmp3xxx_setl(BM_APBH_CTRL0_CLKGATE, REGS_APBH_BASE + HW_APBH_CTRL0); + stmp3xxx_setl(BM_APBX_CTRL0_CLKGATE, REGS_APBX_BASE + HW_APBX_CTRL0); +} + +void stmp3xxx_dma_resume(void) +{ + stmp3xxx_clearl(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST, + REGS_APBH_BASE + HW_APBH_CTRL0); + stmp3xxx_clearl(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST, + REGS_APBX_BASE + HW_APBX_CTRL0); +} + +#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) +{ + stmp3xxx_clearl(BM_APBH_CTRL0_CLKGATE | BM_APBH_CTRL0_SFTRST, + REGS_APBH_BASE + HW_APBH_CTRL0); + stmp3xxx_clearl(BM_APBX_CTRL0_CLKGATE | BM_APBX_CTRL0_SFTRST, + REGS_APBX_BASE + HW_APBX_CTRL0); +#ifdef CONFIG_CPU_FREQ + cpufreq_register_notifier(&dma_cpufreq_nb.nb, + CPUFREQ_TRANSITION_NOTIFIER); +#endif /* CONFIG_CPU_FREQ */ +} |
