From: Haavard Skinnemoen Date: Wed, 17 Sep 2008 18:53:55 +0000 (+0200) Subject: atmel-mci: support multiple mmc slots X-Git-Tag: firefly_0821_release~17130^2~10^2~3 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=965ebf33ea5afb6386f5b57cc71e6572253746b3;p=firefly-linux-kernel-4.4.55.git atmel-mci: support multiple mmc slots The Atmel MCI controller can drive multiple cards through separate sets of pins, but only one at a time. This patch adds support for multiplexing access to the controller so that multiple card slots can be used as if they were hooked up to separate mmc controllers. The atmel-mci driver registers each slot as a separate mmc_host. Both access the same common controller state, but they also have some state on their own for card detection/write protect handling, and separate shadows of the MR and SDCR registers. When one of the slots receives a request from the mmc core, the common controller state is checked. If it's idle, the request is submitted immediately. If not, the request is added to a queue. When a request is done, the queue is checked and if there is a queued request, it is submitted before the completion callback is called. This patch also includes a few cleanups and fixes, including a locking overhaul. I had to change the locking extensively in any case, so I might as well try to get it right. The driver no longer takes any irq-safe locks, which may or may not improve the overall system performance. This patch also adds a bit of documentation of the internal data structures. Signed-off-by: Haavard Skinnemoen --- diff --git a/arch/avr32/include/asm/atmel-mci.h b/arch/avr32/include/asm/atmel-mci.h index d38c64ca41e8..5d5ae1295cfd 100644 --- a/arch/avr32/include/asm/atmel-mci.h +++ b/arch/avr32/include/asm/atmel-mci.h @@ -1,6 +1,8 @@ #ifndef __ASM_AVR32_ATMEL_MCI_H #define __ASM_AVR32_ATMEL_MCI_H +#define ATMEL_MCI_MAX_NR_SLOTS 2 + /** * struct mci_slot_pdata - board-specific per-slot configuration * @bus_width: Number of data lines wired up the slot @@ -11,6 +13,10 @@ * set to 0. The other fields are ignored in this case. * * Any pins that aren't available should be set to a negative value. + * + * Note that support for multiple slots is experimental -- some cards + * might get upset if we don't get the clock management exactly right. + * But in most cases, it should work just fine. */ struct mci_slot_pdata { unsigned int bus_width; @@ -23,7 +29,7 @@ struct mci_slot_pdata { * @slot: Per-slot configuration data. */ struct mci_platform_data { - struct mci_slot_pdata slot[2]; + struct mci_slot_pdata slot[ATMEL_MCI_MAX_NR_SLOTS]; }; #endif /* __ASM_AVR32_ATMEL_MCI_H */ diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 8170905a0401..d8ab35175a53 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -42,20 +42,86 @@ enum { }; enum atmel_mci_state { - STATE_SENDING_CMD = 0, + STATE_IDLE = 0, + STATE_SENDING_CMD, STATE_SENDING_DATA, STATE_DATA_BUSY, STATE_SENDING_STOP, STATE_DATA_ERROR, }; +/** + * struct atmel_mci - MMC controller state shared between all slots + * @lock: Spinlock protecting the queue and associated data. + * @regs: Pointer to MMIO registers. + * @sg: Scatterlist entry currently being processed by PIO code, if any. + * @pio_offset: Offset into the current scatterlist entry. + * @cur_slot: The slot which is currently using the controller. + * @mrq: The request currently being processed on @cur_slot, + * or NULL if the controller is idle. + * @cmd: The command currently being sent to the card, or NULL. + * @data: The data currently being transferred, or NULL if no data + * transfer is in progress. + * @cmd_status: Snapshot of SR taken upon completion of the current + * command. Only valid when EVENT_CMD_COMPLETE is pending. + * @data_status: Snapshot of SR taken upon completion of the current + * data transfer. Only valid when EVENT_DATA_COMPLETE or + * EVENT_DATA_ERROR is pending. + * @stop_cmdr: Value to be loaded into CMDR when the stop command is + * to be sent. + * @tasklet: Tasklet running the request state machine. + * @pending_events: Bitmask of events flagged by the interrupt handler + * to be processed by the tasklet. + * @completed_events: Bitmask of events which the state machine has + * processed. + * @state: Tasklet state. + * @queue: List of slots waiting for access to the controller. + * @need_clock_update: Update the clock rate before the next request. + * @need_reset: Reset controller before next request. + * @mode_reg: Value of the MR register. + * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus + * rate and timeout calculations. + * @mapbase: Physical address of the MMIO registers. + * @mck: The peripheral bus clock hooked up to the MMC controller. + * @pdev: Platform device associated with the MMC controller. + * @slot: Slots sharing this MMC controller. + * + * Locking + * ======= + * + * @lock is a softirq-safe spinlock protecting @queue as well as + * @cur_slot, @mrq and @state. These must always be updated + * at the same time while holding @lock. + * + * @lock also protects mode_reg and need_clock_update since these are + * used to synchronize mode register updates with the queue + * processing. + * + * The @mrq field of struct atmel_mci_slot is also protected by @lock, + * and must always be written at the same time as the slot is added to + * @queue. + * + * @pending_events and @completed_events are accessed using atomic bit + * operations, so they don't need any locking. + * + * None of the fields touched by the interrupt handler need any + * locking. However, ordering is important: Before EVENT_DATA_ERROR or + * EVENT_DATA_COMPLETE is set in @pending_events, all data-related + * interrupts must be disabled and @data_status updated with a + * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the + * CMDRDY interupt must be disabled and @cmd_status updated with a + * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the + * bytes_xfered field of @data must be written. This is ensured by + * using barriers. + */ struct atmel_mci { - struct mmc_host *mmc; + spinlock_t lock; void __iomem *regs; struct scatterlist *sg; unsigned int pio_offset; + struct atmel_mci_slot *cur_slot; struct mmc_request *mrq; struct mmc_command *cmd; struct mmc_data *data; @@ -64,25 +130,59 @@ struct atmel_mci { u32 data_status; u32 stop_cmdr; - u32 mode_reg; - u32 sdc_reg; - struct tasklet_struct tasklet; unsigned long pending_events; unsigned long completed_events; enum atmel_mci_state state; + struct list_head queue; - int present; - int detect_pin; - int wp_pin; - - /* For detect pin debouncing */ - struct timer_list detect_timer; - + bool need_clock_update; + bool need_reset; + u32 mode_reg; unsigned long bus_hz; unsigned long mapbase; struct clk *mck; struct platform_device *pdev; + + struct atmel_mci_slot *slot[ATMEL_MCI_MAX_NR_SLOTS]; +}; + +/** + * struct atmel_mci_slot - MMC slot state + * @mmc: The mmc_host representing this slot. + * @host: The MMC controller this slot is using. + * @sdc_reg: Value of SDCR to be written before using this slot. + * @mrq: mmc_request currently being processed or waiting to be + * processed, or NULL when the slot is idle. + * @queue_node: List node for placing this node in the @queue list of + * &struct atmel_mci. + * @clock: Clock rate configured by set_ios(). Protected by host->lock. + * @flags: Random state bits associated with the slot. + * @detect_pin: GPIO pin used for card detection, or negative if not + * available. + * @wp_pin: GPIO pin used for card write protect sending, or negative + * if not available. + * @detect_timer: Timer used for debouncing @detect_pin interrupts. + */ +struct atmel_mci_slot { + struct mmc_host *mmc; + struct atmel_mci *host; + + u32 sdc_reg; + + struct mmc_request *mrq; + struct list_head queue_node; + + unsigned int clock; + unsigned long flags; +#define ATMCI_CARD_PRESENT 0 +#define ATMCI_CARD_NEED_INIT 1 +#define ATMCI_SHUTDOWN 2 + + int detect_pin; + int wp_pin; + + struct timer_list detect_timer; }; #define atmci_test_and_clear_pending(host, event) \ @@ -98,14 +198,15 @@ struct atmel_mci { */ static int atmci_req_show(struct seq_file *s, void *v) { - struct atmel_mci *host = s->private; - struct mmc_request *mrq = host->mrq; + struct atmel_mci_slot *slot = s->private; + struct mmc_request *mrq; struct mmc_command *cmd; struct mmc_command *stop; struct mmc_data *data; /* Make sure we get a consistent snapshot */ - spin_lock_irq(&host->mmc->lock); + spin_lock_bh(&slot->host->lock); + mrq = slot->mrq; if (mrq) { cmd = mrq->cmd; @@ -130,7 +231,7 @@ static int atmci_req_show(struct seq_file *s, void *v) stop->resp[2], stop->error); } - spin_unlock_irq(&host->mmc->lock); + spin_unlock_bh(&slot->host->lock); return 0; } @@ -193,12 +294,16 @@ static int atmci_regs_show(struct seq_file *s, void *v) if (!buf) return -ENOMEM; - /* Grab a more or less consistent snapshot */ - spin_lock_irq(&host->mmc->lock); + /* + * Grab a more or less consistent snapshot. Note that we're + * not disabling interrupts, so IMR and SR may not be + * consistent. + */ + spin_lock_bh(&host->lock); clk_enable(host->mck); memcpy_fromio(buf, host->regs, MCI_REGS_SIZE); clk_disable(host->mck); - spin_unlock_irq(&host->mmc->lock); + spin_unlock_bh(&host->lock); seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n", buf[MCI_MR / 4], @@ -236,13 +341,13 @@ static const struct file_operations atmci_regs_fops = { .release = single_release, }; -static void atmci_init_debugfs(struct atmel_mci *host) +static void atmci_init_debugfs(struct atmel_mci_slot *slot) { - struct mmc_host *mmc; - struct dentry *root; - struct dentry *node; + struct mmc_host *mmc = slot->mmc; + struct atmel_mci *host = slot->host; + struct dentry *root; + struct dentry *node; - mmc = host->mmc; root = mmc->debugfs_root; if (!root) return; @@ -254,7 +359,7 @@ static void atmci_init_debugfs(struct atmel_mci *host) if (!node) goto err; - node = debugfs_create_file("req", S_IRUSR, root, host, &atmci_req_fops); + node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops); if (!node) goto err; @@ -275,8 +380,7 @@ static void atmci_init_debugfs(struct atmel_mci *host) return; err: - dev_err(&host->pdev->dev, - "failed to initialize debugfs for controller\n"); + dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n"); } static inline unsigned int ns_to_clocks(struct atmel_mci *host, @@ -286,7 +390,7 @@ static inline unsigned int ns_to_clocks(struct atmel_mci *host, } static void atmci_set_timeout(struct atmel_mci *host, - struct mmc_data *data) + struct atmel_mci_slot *slot, struct mmc_data *data) { static unsigned dtomul_to_shift[] = { 0, 4, 7, 8, 10, 12, 16, 20 @@ -309,7 +413,7 @@ static void atmci_set_timeout(struct atmel_mci *host, dtocyc = 15; } - dev_vdbg(&host->mmc->class_dev, "setting timeout to %u cycles\n", + dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n", dtocyc << dtomul_to_shift[dtomul]); mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc))); } @@ -362,13 +466,12 @@ static u32 atmci_prepare_command(struct mmc_host *mmc, } static void atmci_start_command(struct atmel_mci *host, - struct mmc_command *cmd, - u32 cmd_flags) + struct mmc_command *cmd, u32 cmd_flags) { WARN_ON(host->cmd); host->cmd = cmd; - dev_vdbg(&host->mmc->class_dev, + dev_vdbg(&host->pdev->dev, "start command: ARGR=0x%08x CMDR=0x%08x\n", cmd->arg, cmd_flags); @@ -376,32 +479,19 @@ static void atmci_start_command(struct atmel_mci *host, mci_writel(host, CMDR, cmd_flags); } -static void send_stop_cmd(struct mmc_host *mmc, struct mmc_data *data) +static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data) { - struct atmel_mci *host = mmc_priv(mmc); - atmci_start_command(host, data->stop, host->stop_cmdr); mci_writel(host, IER, MCI_CMDRDY); } -static void atmci_request_end(struct mmc_host *mmc, struct mmc_request *mrq) -{ - struct atmel_mci *host = mmc_priv(mmc); - - WARN_ON(host->cmd || host->data); - host->mrq = NULL; - - mmc_request_done(mmc, mrq); -} - /* * Returns a mask of interrupt flags to be enabled after the whole * request has been prepared. */ -static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data) +static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data) { - struct atmel_mci *host = mmc_priv(mmc); - u32 iflags; + u32 iflags; data->error = -EINPROGRESS; @@ -409,10 +499,19 @@ static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data) host->sg = NULL; host->data = data; - dev_vdbg(&mmc->class_dev, "BLKR=0x%08x\n", - MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz)); - iflags = ATMCI_DATA_ERROR_FLAGS; + + /* + * Errata: MMC data write operation with less than 12 + * bytes is impossible. + * + * Errata: MCI Transmit Data Register (TDR) FIFO + * corruption when length is not multiple of 4. + */ + if (data->blocks * data->blksz < 12 + || (data->blocks * data->blksz) & 3) + host->need_reset = true; + host->sg = data->sg; host->pio_offset = 0; if (data->flags & MMC_DATA_READ) @@ -423,62 +522,62 @@ static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data) return iflags; } -static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) +static void atmci_start_request(struct atmel_mci *host, + struct atmel_mci_slot *slot) { - struct atmel_mci *host = mmc_priv(mmc); - struct mmc_data *data; + struct mmc_request *mrq; struct mmc_command *cmd; + struct mmc_data *data; u32 iflags; - u32 cmdflags = 0; - - iflags = mci_readl(host, IMR); - if (iflags) - dev_warn(&mmc->class_dev, "WARNING: IMR=0x%08x\n", - mci_readl(host, IMR)); - - WARN_ON(host->mrq != NULL); - - /* - * We may "know" the card is gone even though there's still an - * electrical connection. If so, we really need to communicate - * this to the MMC core since there won't be any more - * interrupts as the card is completely removed. Otherwise, - * the MMC core might believe the card is still there even - * though the card was just removed very slowly. - */ - if (!host->present) { - mrq->cmd->error = -ENOMEDIUM; - mmc_request_done(mmc, mrq); - return; - } + u32 cmdflags; + mrq = slot->mrq; + host->cur_slot = slot; host->mrq = mrq; + host->pending_events = 0; host->completed_events = 0; - host->state = STATE_SENDING_CMD; - /* We don't support multiple blocks of weird lengths. */ + if (host->need_reset) { + mci_writel(host, CR, MCI_CR_SWRST); + mci_writel(host, CR, MCI_CR_MCIEN); + mci_writel(host, MR, host->mode_reg); + host->need_reset = false; + } + mci_writel(host, SDCR, slot->sdc_reg); + + iflags = mci_readl(host, IMR); + if (iflags) + dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n", + iflags); + + if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) { + /* Send init sequence (74 clock cycles) */ + mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT); + while (!(mci_readl(host, SR) & MCI_CMDRDY)) + cpu_relax(); + } data = mrq->data; if (data) { - if (data->blocks > 1 && data->blksz & 3) - goto fail; - atmci_set_timeout(host, data); + atmci_set_timeout(host, slot, data); /* Must set block count/size before sending command */ mci_writel(host, BLKR, MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz)); + dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n", + MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz)); } iflags = MCI_CMDRDY; cmd = mrq->cmd; - cmdflags = atmci_prepare_command(mmc, cmd); + cmdflags = atmci_prepare_command(slot->mmc, cmd); atmci_start_command(host, cmd, cmdflags); if (data) - iflags |= atmci_submit_data(mmc, data); + iflags |= atmci_submit_data(host, data); if (mrq->stop) { - host->stop_cmdr = atmci_prepare_command(mmc, mrq->stop); + host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop); host->stop_cmdr |= MCI_CMDR_STOP_XFER; if (!(data->flags & MMC_DATA_WRITE)) host->stop_cmdr |= MCI_CMDR_TRDIR_READ; @@ -495,65 +594,156 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) * prepared yet.) */ mci_writel(host, IER, iflags); +} - return; +static void atmci_queue_request(struct atmel_mci *host, + struct atmel_mci_slot *slot, struct mmc_request *mrq) +{ + dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n", + host->state); + + spin_lock_bh(&host->lock); + slot->mrq = mrq; + if (host->state == STATE_IDLE) { + host->state = STATE_SENDING_CMD; + atmci_start_request(host, slot); + } else { + list_add_tail(&slot->queue_node, &host->queue); + } + spin_unlock_bh(&host->lock); +} -fail: - host->mrq = NULL; - mrq->cmd->error = -EINVAL; - mmc_request_done(mmc, mrq); +static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) +{ + struct atmel_mci_slot *slot = mmc_priv(mmc); + struct atmel_mci *host = slot->host; + struct mmc_data *data; + + WARN_ON(slot->mrq); + + /* + * We may "know" the card is gone even though there's still an + * electrical connection. If so, we really need to communicate + * this to the MMC core since there won't be any more + * interrupts as the card is completely removed. Otherwise, + * the MMC core might believe the card is still there even + * though the card was just removed very slowly. + */ + if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) { + mrq->cmd->error = -ENOMEDIUM; + mmc_request_done(mmc, mrq); + return; + } + + /* We don't support multiple blocks of weird lengths. */ + data = mrq->data; + if (data && data->blocks > 1 && data->blksz & 3) { + mrq->cmd->error = -EINVAL; + mmc_request_done(mmc, mrq); + } + + atmci_queue_request(host, slot, mrq); } static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci_slot *slot = mmc_priv(mmc); + struct atmel_mci *host = slot->host; + unsigned int i; - host->sdc_reg &= ~MCI_SDCBUS_MASK; + slot->sdc_reg &= ~MCI_SDCBUS_MASK; switch (ios->bus_width) { case MMC_BUS_WIDTH_1: - host->sdc_reg |= MCI_SDCBUS_1BIT; + slot->sdc_reg |= MCI_SDCBUS_1BIT; break; case MMC_BUS_WIDTH_4: - host->sdc_reg = MCI_SDCBUS_4BIT; + slot->sdc_reg = MCI_SDCBUS_4BIT; break; } if (ios->clock) { + unsigned int clock_min = ~0U; u32 clkdiv; - if (!host->mode_reg) + spin_lock_bh(&host->lock); + if (!host->mode_reg) { clk_enable(host->mck); + mci_writel(host, CR, MCI_CR_SWRST); + mci_writel(host, CR, MCI_CR_MCIEN); + } - /* Set clock rate */ - clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * ios->clock) - 1; + /* + * Use mirror of ios->clock to prevent race with mmc + * core ios update when finding the minimum. + */ + slot->clock = ios->clock; + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) { + if (host->slot[i] && host->slot[i]->clock + && host->slot[i]->clock < clock_min) + clock_min = host->slot[i]->clock; + } + + /* Calculate clock divider */ + clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1; if (clkdiv > 255) { dev_warn(&mmc->class_dev, "clock %u too slow; using %lu\n", - ios->clock, host->bus_hz / (2 * 256)); + clock_min, host->bus_hz / (2 * 256)); clkdiv = 255; } + /* + * WRPROOF and RDPROOF prevent overruns/underruns by + * stopping the clock when the FIFO is full/empty. + * This state is not expected to last for long. + */ host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF | MCI_MR_RDPROOF; - mci_writel(host, CR, MCI_CR_MCIEN); - mci_writel(host, MR, host->mode_reg); - mci_writel(host, SDCR, host->sdc_reg); + if (list_empty(&host->queue)) + mci_writel(host, MR, host->mode_reg); + else + host->need_clock_update = true; + + spin_unlock_bh(&host->lock); } else { - mci_writel(host, CR, MCI_CR_MCIDIS); - if (host->mode_reg) { - mci_readl(host, MR); - clk_disable(host->mck); + bool any_slot_active = false; + + spin_lock_bh(&host->lock); + slot->clock = 0; + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) { + if (host->slot[i] && host->slot[i]->clock) { + any_slot_active = true; + break; + } } - host->mode_reg = 0; + if (!any_slot_active) { + mci_writel(host, CR, MCI_CR_MCIDIS); + if (host->mode_reg) { + mci_readl(host, MR); + clk_disable(host->mck); + } + host->mode_reg = 0; + } + spin_unlock_bh(&host->lock); } switch (ios->power_mode) { + case MMC_POWER_UP: + set_bit(ATMCI_CARD_NEED_INIT, &slot->flags); + break; default: /* * TODO: None of the currently available AVR32-based * boards allow MMC power to be turned off. Implement * power control when this can be tested properly. + * + * We also need to hook this into the clock management + * somehow so that newly inserted cards aren't + * subjected to a fast clock before we have a chance + * to figure out what the maximum rate is. Currently, + * there's no way to avoid this, and there never will + * be for boards that don't support power control. */ break; } @@ -561,28 +751,77 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) static int atmci_get_ro(struct mmc_host *mmc) { - int read_only = 0; - struct atmel_mci *host = mmc_priv(mmc); + int read_only = -ENOSYS; + struct atmel_mci_slot *slot = mmc_priv(mmc); - if (gpio_is_valid(host->wp_pin)) { - read_only = gpio_get_value(host->wp_pin); + if (gpio_is_valid(slot->wp_pin)) { + read_only = gpio_get_value(slot->wp_pin); dev_dbg(&mmc->class_dev, "card is %s\n", read_only ? "read-only" : "read-write"); - } else { - dev_dbg(&mmc->class_dev, - "no pin for checking read-only switch." - " Assuming write-enable.\n"); } return read_only; } -static struct mmc_host_ops atmci_ops = { +static int atmci_get_cd(struct mmc_host *mmc) +{ + int present = -ENOSYS; + struct atmel_mci_slot *slot = mmc_priv(mmc); + + if (gpio_is_valid(slot->detect_pin)) { + present = !gpio_get_value(slot->detect_pin); + dev_dbg(&mmc->class_dev, "card is %spresent\n", + present ? "" : "not "); + } + + return present; +} + +static const struct mmc_host_ops atmci_ops = { .request = atmci_request, .set_ios = atmci_set_ios, .get_ro = atmci_get_ro, + .get_cd = atmci_get_cd, }; +/* Called with host->lock held */ +static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq) + __releases(&host->lock) + __acquires(&host->lock) +{ + struct atmel_mci_slot *slot = NULL; + struct mmc_host *prev_mmc = host->cur_slot->mmc; + + WARN_ON(host->cmd || host->data); + + /* + * Update the MMC clock rate if necessary. This may be + * necessary if set_ios() is called when a different slot is + * busy transfering data. + */ + if (host->need_clock_update) + mci_writel(host, MR, host->mode_reg); + + host->cur_slot->mrq = NULL; + host->mrq = NULL; + if (!list_empty(&host->queue)) { + slot = list_entry(host->queue.next, + struct atmel_mci_slot, queue_node); + list_del(&slot->queue_node); + dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n", + mmc_hostname(slot->mmc)); + host->state = STATE_SENDING_CMD; + atmci_start_request(host, slot); + } else { + dev_vdbg(&host->pdev->dev, "list empty\n"); + host->state = STATE_IDLE; + } + + spin_unlock(&host->lock); + mmc_request_done(prev_mmc, mrq); + spin_lock(&host->lock); +} + static void atmci_command_complete(struct atmel_mci *host, struct mmc_command *cmd) { @@ -604,7 +843,7 @@ static void atmci_command_complete(struct atmel_mci *host, cmd->error = 0; if (cmd->error) { - dev_dbg(&host->mmc->class_dev, + dev_dbg(&host->pdev->dev, "command error: status=0x%08x\n", status); if (cmd->data) { @@ -618,81 +857,102 @@ static void atmci_command_complete(struct atmel_mci *host, static void atmci_detect_change(unsigned long data) { - struct atmel_mci *host = (struct atmel_mci *)data; - struct mmc_request *mrq = host->mrq; - int present; + struct atmel_mci_slot *slot = (struct atmel_mci_slot *)data; + bool present; + bool present_old; /* - * atmci_remove() sets detect_pin to -1 before freeing the - * interrupt. We must not re-enable the interrupt if it has - * been freed. + * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before + * freeing the interrupt. We must not re-enable the interrupt + * if it has been freed, and if we're shutting down, it + * doesn't really matter whether the card is present or not. */ smp_rmb(); - if (!gpio_is_valid(host->detect_pin)) + if (test_bit(ATMCI_SHUTDOWN, &slot->flags)) return; - enable_irq(gpio_to_irq(host->detect_pin)); - present = !gpio_get_value(host->detect_pin); + enable_irq(gpio_to_irq(slot->detect_pin)); + present = !gpio_get_value(slot->detect_pin); + present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags); - dev_vdbg(&host->pdev->dev, "detect change: %d (was %d)\n", - present, host->present); + dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n", + present, present_old); - if (present != host->present) { - dev_dbg(&host->mmc->class_dev, "card %s\n", + if (present != present_old) { + struct atmel_mci *host = slot->host; + struct mmc_request *mrq; + + dev_dbg(&slot->mmc->class_dev, "card %s\n", present ? "inserted" : "removed"); - host->present = present; - /* Reset controller if card is gone */ - if (!present) { - mci_writel(host, CR, MCI_CR_SWRST); - mci_writel(host, IDR, ~0UL); - mci_writel(host, CR, MCI_CR_MCIEN); - } + spin_lock(&host->lock); + + if (!present) + clear_bit(ATMCI_CARD_PRESENT, &slot->flags); + else + set_bit(ATMCI_CARD_PRESENT, &slot->flags); /* Clean up queue if present */ + mrq = slot->mrq; if (mrq) { - /* - * Reset controller to terminate any ongoing - * commands or data transfers. - */ - mci_writel(host, CR, MCI_CR_SWRST); - mci_readl(host, SR); - - host->data = NULL; - host->cmd = NULL; - - switch (host->state) { - case STATE_SENDING_CMD: - mrq->cmd->error = -ENOMEDIUM; - if (!mrq->data) + if (mrq == host->mrq) { + /* + * Reset controller to terminate any ongoing + * commands or data transfers. + */ + mci_writel(host, CR, MCI_CR_SWRST); + mci_writel(host, CR, MCI_CR_MCIEN); + mci_writel(host, MR, host->mode_reg); + + host->data = NULL; + host->cmd = NULL; + + switch (host->state) { + case STATE_IDLE: break; - /* fall through */ - case STATE_SENDING_DATA: - mrq->data->error = -ENOMEDIUM; - break; - case STATE_DATA_BUSY: - case STATE_DATA_ERROR: - if (mrq->data->error == -EINPROGRESS) + case STATE_SENDING_CMD: + mrq->cmd->error = -ENOMEDIUM; + if (!mrq->data) + break; + /* fall through */ + case STATE_SENDING_DATA: mrq->data->error = -ENOMEDIUM; - if (!mrq->stop) break; - /* fall through */ - case STATE_SENDING_STOP: - mrq->stop->error = -ENOMEDIUM; - break; - } + case STATE_DATA_BUSY: + case STATE_DATA_ERROR: + if (mrq->data->error == -EINPROGRESS) + mrq->data->error = -ENOMEDIUM; + if (!mrq->stop) + break; + /* fall through */ + case STATE_SENDING_STOP: + mrq->stop->error = -ENOMEDIUM; + break; + } - atmci_request_end(host->mmc, mrq); + atmci_request_end(host, mrq); + } else { + list_del(&slot->queue_node); + mrq->cmd->error = -ENOMEDIUM; + if (mrq->data) + mrq->data->error = -ENOMEDIUM; + if (mrq->stop) + mrq->stop->error = -ENOMEDIUM; + + spin_unlock(&host->lock); + mmc_request_done(slot->mmc, mrq); + spin_lock(&host->lock); + } } + spin_unlock(&host->lock); - mmc_detect_change(host->mmc, 0); + mmc_detect_change(slot->mmc, 0); } } static void atmci_tasklet_func(unsigned long priv) { - struct mmc_host *mmc = (struct mmc_host *)priv; - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci *host = (struct atmel_mci *)priv; struct mmc_request *mrq = host->mrq; struct mmc_data *data = host->data; struct mmc_command *cmd = host->cmd; @@ -700,9 +960,11 @@ static void atmci_tasklet_func(unsigned long priv) enum atmel_mci_state prev_state; u32 status; + spin_lock(&host->lock); + state = host->state; - dev_vdbg(&mmc->class_dev, + dev_vdbg(&host->pdev->dev, "tasklet: state %u pending/completed/mask %lx/%lx/%x\n", state, host->pending_events, host->completed_events, mci_readl(host, IMR)); @@ -711,6 +973,9 @@ static void atmci_tasklet_func(unsigned long priv) prev_state = state; switch (state) { + case STATE_IDLE: + break; + case STATE_SENDING_CMD: if (!atmci_test_and_clear_pending(host, EVENT_CMD_COMPLETE)) @@ -720,8 +985,8 @@ static void atmci_tasklet_func(unsigned long priv) atmci_set_completed(host, EVENT_CMD_COMPLETE); atmci_command_complete(host, mrq->cmd); if (!mrq->data || cmd->error) { - atmci_request_end(mmc, host->mrq); - break; + atmci_request_end(host, host->mrq); + goto unlock; } prev_state = state = STATE_SENDING_DATA; @@ -731,7 +996,7 @@ static void atmci_tasklet_func(unsigned long priv) if (atmci_test_and_clear_pending(host, EVENT_DATA_ERROR)) { if (data->stop) - send_stop_cmd(host->mmc, data); + send_stop_cmd(host, data); state = STATE_DATA_ERROR; break; } @@ -754,15 +1019,15 @@ static void atmci_tasklet_func(unsigned long priv) status = host->data_status; if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) { if (status & MCI_DTOE) { - dev_dbg(&mmc->class_dev, + dev_dbg(&host->pdev->dev, "data timeout error\n"); data->error = -ETIMEDOUT; } else if (status & MCI_DCRCE) { - dev_dbg(&mmc->class_dev, + dev_dbg(&host->pdev->dev, "data CRC error\n"); data->error = -EILSEQ; } else { - dev_dbg(&mmc->class_dev, + dev_dbg(&host->pdev->dev, "data FIFO error (status=%08x)\n", status); data->error = -EIO; @@ -773,14 +1038,13 @@ static void atmci_tasklet_func(unsigned long priv) } if (!data->stop) { - atmci_request_end(mmc, host->mrq); - prev_state = state; - break; + atmci_request_end(host, host->mrq); + goto unlock; } prev_state = state = STATE_SENDING_STOP; if (!data->error) - send_stop_cmd(host->mmc, data); + send_stop_cmd(host, data); /* fall through */ case STATE_SENDING_STOP: @@ -790,9 +1054,8 @@ static void atmci_tasklet_func(unsigned long priv) host->cmd = NULL; atmci_command_complete(host, mrq->stop); - atmci_request_end(mmc, host->mrq); - prev_state = state; - break; + atmci_request_end(host, host->mrq); + goto unlock; case STATE_DATA_ERROR: if (!atmci_test_and_clear_pending(host, @@ -805,6 +1068,9 @@ static void atmci_tasklet_func(unsigned long priv) } while (state != prev_state); host->state = state; + +unlock: + spin_unlock(&host->lock); } static void atmci_read_data_pio(struct atmel_mci *host) @@ -854,9 +1120,11 @@ static void atmci_read_data_pio(struct atmel_mci *host) mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY | ATMCI_DATA_ERROR_FLAGS)); host->data_status = status; + data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_ERROR); tasklet_schedule(&host->tasklet); - break; + return; } } while (status & MCI_RXRDY); @@ -869,6 +1137,7 @@ done: mci_writel(host, IDR, MCI_RXRDY); mci_writel(host, IER, MCI_NOTBUSY); data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_XFER_COMPLETE); } @@ -922,9 +1191,11 @@ static void atmci_write_data_pio(struct atmel_mci *host) mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY | ATMCI_DATA_ERROR_FLAGS)); host->data_status = status; + data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_ERROR); tasklet_schedule(&host->tasklet); - break; + return; } } while (status & MCI_TXRDY); @@ -937,29 +1208,26 @@ done: mci_writel(host, IDR, MCI_TXRDY); mci_writel(host, IER, MCI_NOTBUSY); data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_XFER_COMPLETE); } -static void atmci_cmd_interrupt(struct mmc_host *mmc, u32 status) +static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status) { - struct atmel_mci *host = mmc_priv(mmc); - mci_writel(host, IDR, MCI_CMDRDY); host->cmd_status = status; + smp_wmb(); atmci_set_pending(host, EVENT_CMD_COMPLETE); tasklet_schedule(&host->tasklet); } static irqreturn_t atmci_interrupt(int irq, void *dev_id) { - struct mmc_host *mmc = dev_id; - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci *host = dev_id; u32 status, mask, pending; unsigned int pass_count = 0; - spin_lock(&mmc->lock); - do { status = mci_readl(host, SR); mask = mci_readl(host, IMR); @@ -971,7 +1239,9 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS | MCI_RXRDY | MCI_TXRDY); pending &= mci_readl(host, IMR); + host->data_status = status; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_ERROR); tasklet_schedule(&host->tasklet); } @@ -979,6 +1249,7 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY); host->data_status = status; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_COMPLETE); tasklet_schedule(&host->tasklet); } @@ -988,18 +1259,15 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) atmci_write_data_pio(host); if (pending & MCI_CMDRDY) - atmci_cmd_interrupt(mmc, status); + atmci_cmd_interrupt(host, status); } while (pass_count++ < 5); - spin_unlock(&mmc->lock); - return pass_count ? IRQ_HANDLED : IRQ_NONE; } static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id) { - struct mmc_host *mmc = dev_id; - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci_slot *slot = dev_id; /* * Disable interrupts until the pin has stabilized and check @@ -1007,21 +1275,122 @@ static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id) * middle of the timer routine when this interrupt triggers. */ disable_irq_nosync(irq); - mod_timer(&host->detect_timer, jiffies + msecs_to_jiffies(20)); + mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20)); return IRQ_HANDLED; } +static int __init atmci_init_slot(struct atmel_mci *host, + struct mci_slot_pdata *slot_data, unsigned int id, + u32 sdc_reg) +{ + struct mmc_host *mmc; + struct atmel_mci_slot *slot; + + mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev); + if (!mmc) + return -ENOMEM; + + slot = mmc_priv(mmc); + slot->mmc = mmc; + slot->host = host; + slot->detect_pin = slot_data->detect_pin; + slot->wp_pin = slot_data->wp_pin; + slot->sdc_reg = sdc_reg; + + mmc->ops = &atmci_ops; + mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512); + mmc->f_max = host->bus_hz / 2; + mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; + if (slot_data->bus_width >= 4) + mmc->caps |= MMC_CAP_4_BIT_DATA; + + mmc->max_hw_segs = 64; + mmc->max_phys_segs = 64; + mmc->max_req_size = 32768 * 512; + mmc->max_blk_size = 32768; + mmc->max_blk_count = 512; + + /* Assume card is present initially */ + set_bit(ATMCI_CARD_PRESENT, &slot->flags); + if (gpio_is_valid(slot->detect_pin)) { + if (gpio_request(slot->detect_pin, "mmc_detect")) { + dev_dbg(&mmc->class_dev, "no detect pin available\n"); + slot->detect_pin = -EBUSY; + } else if (gpio_get_value(slot->detect_pin)) { + clear_bit(ATMCI_CARD_PRESENT, &slot->flags); + } + } + + if (!gpio_is_valid(slot->detect_pin)) + mmc->caps |= MMC_CAP_NEEDS_POLL; + + if (gpio_is_valid(slot->wp_pin)) { + if (gpio_request(slot->wp_pin, "mmc_wp")) { + dev_dbg(&mmc->class_dev, "no WP pin available\n"); + slot->wp_pin = -EBUSY; + } + } + + host->slot[id] = slot; + mmc_add_host(mmc); + + if (gpio_is_valid(slot->detect_pin)) { + int ret; + + setup_timer(&slot->detect_timer, atmci_detect_change, + (unsigned long)slot); + + ret = request_irq(gpio_to_irq(slot->detect_pin), + atmci_detect_interrupt, + IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, + "mmc-detect", slot); + if (ret) { + dev_dbg(&mmc->class_dev, + "could not request IRQ %d for detect pin\n", + gpio_to_irq(slot->detect_pin)); + gpio_free(slot->detect_pin); + slot->detect_pin = -EBUSY; + } + } + + atmci_init_debugfs(slot); + + return 0; +} + +static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot, + unsigned int id) +{ + /* Debugfs stuff is cleaned up by mmc core */ + + set_bit(ATMCI_SHUTDOWN, &slot->flags); + smp_wmb(); + + mmc_remove_host(slot->mmc); + + if (gpio_is_valid(slot->detect_pin)) { + int pin = slot->detect_pin; + + free_irq(gpio_to_irq(pin), slot); + del_timer_sync(&slot->detect_timer); + gpio_free(pin); + } + if (gpio_is_valid(slot->wp_pin)) + gpio_free(slot->wp_pin); + + slot->host->slot[id] = NULL; + mmc_free_host(slot->mmc); +} + static int __init atmci_probe(struct platform_device *pdev) { struct mci_platform_data *pdata; - struct mci_slot_pdata *slot; - struct atmel_mci *host; - struct mmc_host *mmc; - struct resource *regs; - u32 sdc_reg; - int irq; - int ret; + struct atmel_mci *host; + struct resource *regs; + unsigned int nr_slots; + int irq; + int ret; regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!regs) @@ -1033,27 +1402,13 @@ static int __init atmci_probe(struct platform_device *pdev) if (irq < 0) return irq; - /* TODO: Allow using several slots at once */ - if (pdata->slot[0].bus_width) { - sdc_reg = MCI_SDCSEL_SLOT_A; - slot = &pdata->slot[0]; - } else if (pdata->slot[1].bus_width) { - sdc_reg = MCI_SDCSEL_SLOT_B; - slot = &pdata->slot[1]; - } else { - return -EINVAL; - } - - mmc = mmc_alloc_host(sizeof(struct atmel_mci), &pdev->dev); - if (!mmc) + host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL); + if (!host) return -ENOMEM; - host = mmc_priv(mmc); host->pdev = pdev; - host->mmc = mmc; - host->detect_pin = slot->detect_pin; - host->wp_pin = slot->wp_pin; - host->sdc_reg = sdc_reg; + spin_lock_init(&host->lock); + INIT_LIST_HEAD(&host->queue); host->mck = clk_get(&pdev->dev, "mci_clk"); if (IS_ERR(host->mck)) { @@ -1073,123 +1428,74 @@ static int __init atmci_probe(struct platform_device *pdev) host->mapbase = regs->start; - mmc->ops = &atmci_ops; - mmc->f_min = (host->bus_hz + 511) / 512; - mmc->f_max = host->bus_hz / 2; - mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; - if (slot->bus_width >= 4) - mmc->caps |= MMC_CAP_4_BIT_DATA; - - mmc->max_hw_segs = 64; - mmc->max_phys_segs = 64; - mmc->max_req_size = 32768 * 512; - mmc->max_blk_size = 32768; - mmc->max_blk_count = 512; - - tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)mmc); + tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host); - ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, mmc); + ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, host); if (ret) goto err_request_irq; - /* Assume card is present if we don't have a detect pin */ - host->present = 1; - if (gpio_is_valid(host->detect_pin)) { - if (gpio_request(host->detect_pin, "mmc_detect")) { - dev_dbg(&mmc->class_dev, "no detect pin available\n"); - host->detect_pin = -1; - } else { - host->present = !gpio_get_value(host->detect_pin); - } - } - - if (!gpio_is_valid(host->detect_pin)) - mmc->caps |= MMC_CAP_NEEDS_POLL; - - if (gpio_is_valid(host->wp_pin)) { - if (gpio_request(host->wp_pin, "mmc_wp")) { - dev_dbg(&mmc->class_dev, "no WP pin available\n"); - host->wp_pin = -1; - } - } - platform_set_drvdata(pdev, host); - mmc_add_host(mmc); - - if (gpio_is_valid(host->detect_pin)) { - setup_timer(&host->detect_timer, atmci_detect_change, - (unsigned long)host); - - ret = request_irq(gpio_to_irq(host->detect_pin), - atmci_detect_interrupt, - IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, - "mmc-detect", mmc); - if (ret) { - dev_dbg(&mmc->class_dev, - "could not request IRQ %d for detect pin\n", - gpio_to_irq(host->detect_pin)); - gpio_free(host->detect_pin); - host->detect_pin = -1; - } + /* We need at least one slot to succeed */ + nr_slots = 0; + ret = -ENODEV; + if (pdata->slot[0].bus_width) { + ret = atmci_init_slot(host, &pdata->slot[0], + MCI_SDCSEL_SLOT_A, 0); + if (!ret) + nr_slots++; + } + if (pdata->slot[1].bus_width) { + ret = atmci_init_slot(host, &pdata->slot[1], + MCI_SDCSEL_SLOT_B, 1); + if (!ret) + nr_slots++; } - dev_info(&mmc->class_dev, - "Atmel MCI controller at 0x%08lx irq %d\n", - host->mapbase, irq); + if (!nr_slots) + goto err_init_slot; - atmci_init_debugfs(host); + dev_info(&pdev->dev, + "Atmel MCI controller at 0x%08lx irq %d, %u slots\n", + host->mapbase, irq, nr_slots); return 0; +err_init_slot: + free_irq(irq, host); err_request_irq: iounmap(host->regs); err_ioremap: clk_put(host->mck); err_clk_get: - mmc_free_host(mmc); + kfree(host); return ret; } static int __exit atmci_remove(struct platform_device *pdev) { - struct atmel_mci *host = platform_get_drvdata(pdev); + struct atmel_mci *host = platform_get_drvdata(pdev); + unsigned int i; platform_set_drvdata(pdev, NULL); - if (host) { - /* Debugfs stuff is cleaned up by mmc core */ - - if (gpio_is_valid(host->detect_pin)) { - int pin = host->detect_pin; - - /* Make sure the timer doesn't enable the interrupt */ - host->detect_pin = -1; - smp_wmb(); - - free_irq(gpio_to_irq(pin), host->mmc); - del_timer_sync(&host->detect_timer); - gpio_free(pin); - } - - mmc_remove_host(host->mmc); - - clk_enable(host->mck); - mci_writel(host, IDR, ~0UL); - mci_writel(host, CR, MCI_CR_MCIDIS); - mci_readl(host, SR); - clk_disable(host->mck); + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) { + if (host->slot[i]) + atmci_cleanup_slot(host->slot[i], i); + } - if (gpio_is_valid(host->wp_pin)) - gpio_free(host->wp_pin); + clk_enable(host->mck); + mci_writel(host, IDR, ~0UL); + mci_writel(host, CR, MCI_CR_MCIDIS); + mci_readl(host, SR); + clk_disable(host->mck); - free_irq(platform_get_irq(pdev, 0), host->mmc); - iounmap(host->regs); + free_irq(platform_get_irq(pdev, 0), host); + iounmap(host->regs); - clk_put(host->mck); + clk_put(host->mck); + kfree(host); - mmc_free_host(host->mmc); - } return 0; }