diff options
author | Stephen Rothwell <sfr@canb.auug.org.au> | 2010-12-09 11:32:15 +1100 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2010-12-09 11:32:15 +1100 |
commit | fdea1faf14bc610d88623f1c42f7641276c9a9f0 (patch) | |
tree | ed7f2fae54c67820894b9828a7727c4ab935a6db /drivers | |
parent | ca99692aed2d84002f00646512770f3196720e92 (diff) | |
parent | 292d10a14990483e5628291bd1c626a28d729659 (diff) |
Merge remote branch 'arm/devel'
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/Kconfig | 2 | ||||
-rw-r--r-- | drivers/Makefile | 2 | ||||
-rw-r--r-- | drivers/amba/bus.c | 39 | ||||
-rw-r--r-- | drivers/clk/Kconfig | 4 | ||||
-rw-r--r-- | drivers/clk/Makefile | 2 | ||||
-rw-r--r-- | drivers/clk/clkdev.c | 176 | ||||
-rw-r--r-- | drivers/mmc/host/mmci.c | 210 | ||||
-rw-r--r-- | drivers/mmc/host/mmci.h | 9 | ||||
-rw-r--r-- | drivers/rtc/rtc-sa1100.c | 63 |
9 files changed, 468 insertions, 39 deletions
diff --git a/drivers/Kconfig b/drivers/Kconfig index a2b902f4d437..3d93b3a3d630 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -111,4 +111,6 @@ source "drivers/xen/Kconfig" source "drivers/staging/Kconfig" source "drivers/platform/Kconfig" + +source "drivers/clk/Kconfig" endmenu diff --git a/drivers/Makefile b/drivers/Makefile index f3ebb30f1b7f..bf15ce7493d2 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -115,3 +115,5 @@ obj-$(CONFIG_VLYNQ) += vlynq/ obj-$(CONFIG_STAGING) += staging/ obj-y += platform/ obj-y += ieee802154/ +#common clk code +obj-y += clk/ diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 2737b9752205..e7df019d29d4 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -147,6 +147,39 @@ static void amba_put_disable_pclk(struct amba_device *pcdev) clk_put(pclk); } +static int amba_get_enable_vcore(struct amba_device *pcdev) +{ + struct regulator *vcore = regulator_get(&pcdev->dev, "vcore"); + int ret; + + pcdev->vcore = vcore; + + if (IS_ERR(vcore)) { + /* It is OK not to supply a vcore regulator */ + if (PTR_ERR(vcore) == -ENODEV) + return 0; + return PTR_ERR(vcore); + } + + ret = regulator_enable(vcore); + if (ret) { + regulator_put(vcore); + pcdev->vcore = ERR_PTR(-ENODEV); + } + + return ret; +} + +static void amba_put_disable_vcore(struct amba_device *pcdev) +{ + struct regulator *vcore = pcdev->vcore; + + if (!IS_ERR(vcore)) { + regulator_disable(vcore); + regulator_put(vcore); + } +} + /* * These are the device model conversion veneers; they convert the * device model structures to our more specific structures. @@ -159,6 +192,10 @@ static int amba_probe(struct device *dev) int ret; do { + ret = amba_get_enable_vcore(pcdev); + if (ret) + break; + ret = amba_get_enable_pclk(pcdev); if (ret) break; @@ -168,6 +205,7 @@ static int amba_probe(struct device *dev) break; amba_put_disable_pclk(pcdev); + amba_put_disable_vcore(pcdev); } while (0); return ret; @@ -180,6 +218,7 @@ static int amba_remove(struct device *dev) int ret = drv->remove(pcdev); amba_put_disable_pclk(pcdev); + amba_put_disable_vcore(pcdev); return ret; } diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig new file mode 100644 index 000000000000..4168c8896e16 --- /dev/null +++ b/drivers/clk/Kconfig @@ -0,0 +1,4 @@ + +config CLKDEV_LOOKUP + bool + select HAVE_CLK diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile new file mode 100644 index 000000000000..07613fa172c9 --- /dev/null +++ b/drivers/clk/Makefile @@ -0,0 +1,2 @@ + +obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c new file mode 100644 index 000000000000..0fc0a79852de --- /dev/null +++ b/drivers/clk/clkdev.c @@ -0,0 +1,176 @@ +/* + * drivers/clk/clkdev.c + * + * Copyright (C) 2008 Russell King. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Helper for the clk API to assist looking up a struct clk. + */ +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/list.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/string.h> +#include <linux/mutex.h> +#include <linux/clk.h> +#include <linux/clkdev.h> + +static LIST_HEAD(clocks); +static DEFINE_MUTEX(clocks_mutex); + +/* + * Find the correct struct clk for the device and connection ID. + * We do slightly fuzzy matching here: + * An entry with a NULL ID is assumed to be a wildcard. + * If an entry has a device ID, it must match + * If an entry has a connection ID, it must match + * Then we take the most specific entry - with the following + * order of precedence: dev+con > dev only > con only. + */ +static struct clk *clk_find(const char *dev_id, const char *con_id) +{ + struct clk_lookup *p; + struct clk *clk = NULL; + int match, best = 0; + + list_for_each_entry(p, &clocks, node) { + match = 0; + if (p->dev_id) { + if (!dev_id || strcmp(p->dev_id, dev_id)) + continue; + match += 2; + } + if (p->con_id) { + if (!con_id || strcmp(p->con_id, con_id)) + continue; + match += 1; + } + + if (match > best) { + clk = p->clk; + if (match != 3) + best = match; + else + break; + } + } + return clk; +} + +struct clk *clk_get_sys(const char *dev_id, const char *con_id) +{ + struct clk *clk; + + mutex_lock(&clocks_mutex); + clk = clk_find(dev_id, con_id); + if (clk && !__clk_get(clk)) + clk = NULL; + mutex_unlock(&clocks_mutex); + + return clk ? clk : ERR_PTR(-ENOENT); +} +EXPORT_SYMBOL(clk_get_sys); + +struct clk *clk_get(struct device *dev, const char *con_id) +{ + const char *dev_id = dev ? dev_name(dev) : NULL; + + return clk_get_sys(dev_id, con_id); +} +EXPORT_SYMBOL(clk_get); + +void clk_put(struct clk *clk) +{ + __clk_put(clk); +} +EXPORT_SYMBOL(clk_put); + +void clkdev_add(struct clk_lookup *cl) +{ + mutex_lock(&clocks_mutex); + list_add_tail(&cl->node, &clocks); + mutex_unlock(&clocks_mutex); +} +EXPORT_SYMBOL(clkdev_add); + +void __init clkdev_add_table(struct clk_lookup *cl, size_t num) +{ + mutex_lock(&clocks_mutex); + while (num--) { + list_add_tail(&cl->node, &clocks); + cl++; + } + mutex_unlock(&clocks_mutex); +} + +#define MAX_DEV_ID 20 +#define MAX_CON_ID 16 + +struct clk_lookup_alloc { + struct clk_lookup cl; + char dev_id[MAX_DEV_ID]; + char con_id[MAX_CON_ID]; +}; + +struct clk_lookup * __init_refok +clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) +{ + struct clk_lookup_alloc *cla; + + cla = __clkdev_alloc(sizeof(*cla)); + if (!cla) + return NULL; + + cla->cl.clk = clk; + if (con_id) { + strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); + cla->cl.con_id = cla->con_id; + } + + if (dev_fmt) { + va_list ap; + + va_start(ap, dev_fmt); + vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); + cla->cl.dev_id = cla->dev_id; + va_end(ap); + } + + return &cla->cl; +} +EXPORT_SYMBOL(clkdev_alloc); + +int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, + struct device *dev) +{ + struct clk *r = clk_get(dev, id); + struct clk_lookup *l; + + if (IS_ERR(r)) + return PTR_ERR(r); + + l = clkdev_alloc(r, alias, alias_dev_name); + clk_put(r); + if (!l) + return -ENODEV; + clkdev_add(l); + return 0; +} +EXPORT_SYMBOL(clk_add_alias); + +/* + * clkdev_drop - remove a clock dynamically allocated + */ +void clkdev_drop(struct clk_lookup *cl) +{ + mutex_lock(&clocks_mutex); + list_del(&cl->node); + mutex_unlock(&clocks_mutex); + kfree(cl); +} +EXPORT_SYMBOL(clkdev_drop); diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 87b4fc6c98c2..82880e89e204 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -19,6 +19,7 @@ #include <linux/highmem.h> #include <linux/log2.h> #include <linux/mmc/host.h> +#include <linux/mmc/card.h> #include <linux/amba/bus.h> #include <linux/clk.h> #include <linux/scatterlist.h> @@ -45,6 +46,12 @@ static unsigned int fmax = 515633; * is asserted (likewise for RX) * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY * is asserted (likewise for RX) + * @broken_blockend: the MCI_DATABLOCKEND is broken on the hardware + * and will not work at all. + * @broken_blockend_dma: the MCI_DATABLOCKEND is broken on the hardware when + * using DMA. + * @sdio: variant supports SDIO + * @st_clkdiv: true if using a ST-specific clock divider algorithm */ struct variant_data { unsigned int clkreg; @@ -52,6 +59,10 @@ struct variant_data { unsigned int datalength_bits; unsigned int fifosize; unsigned int fifohalfsize; + bool broken_blockend; + bool broken_blockend_dma; + bool sdio; + bool st_clkdiv; }; static struct variant_data variant_arm = { @@ -65,6 +76,8 @@ static struct variant_data variant_u300 = { .fifohalfsize = 8 * 4, .clkreg_enable = 1 << 13, /* HWFCEN */ .datalength_bits = 16, + .broken_blockend_dma = true, + .sdio = true, }; static struct variant_data variant_ux500 = { @@ -73,7 +86,11 @@ static struct variant_data variant_ux500 = { .clkreg = MCI_CLK_ENABLE, .clkreg_enable = 1 << 14, /* HWFCEN */ .datalength_bits = 24, + .broken_blockend = true, + .sdio = true, + .st_clkdiv = true, }; + /* * This must be called with host->lock held */ @@ -84,9 +101,30 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired) if (desired) { if (desired >= host->mclk) { - clk = MCI_CLK_BYPASS; + /* + * The ST clock divider does not like the bypass bit, + * even though it's available. Instead the datasheet + * recommends setting the divider to zero. + */ + if (!variant->st_clkdiv) + clk = MCI_CLK_BYPASS; host->cclk = host->mclk; + } else if (variant->st_clkdiv) { + /* + * DB8500 TRM says f = mclk / (clkdiv + 2) + * => clkdiv = (mclk / f) - 2 + * Round the divider up so we don't exceed the max + * frequency + */ + clk = DIV_ROUND_UP(host->mclk, desired) - 2; + if (clk >= 256) + clk = 255; + host->cclk = host->mclk / (clk + 2); } else { + /* + * PL180 TRM says f = mclk / (2 * (clkdiv + 1)) + * => clkdiv = mclk / (2 * f) - 1 + */ clk = host->mclk / (2 * desired) - 1; if (clk >= 256) clk = 255; @@ -129,10 +167,26 @@ mmci_request_end(struct mmci_host *host, struct mmc_request *mrq) spin_lock(&host->lock); } +static void mmci_set_mask1(struct mmci_host *host, unsigned int mask) +{ + void __iomem *base = host->base; + + if (host->singleirq) { + unsigned int mask0 = readl(base + MMCIMASK0); + + mask0 &= ~MCI_IRQ1MASK; + mask0 |= mask; + + writel(mask0, base + MMCIMASK0); + } + + writel(mask, base + MMCIMASK1); +} + static void mmci_stop_data(struct mmci_host *host) { writel(0, host->base + MMCIDATACTRL); - writel(0, host->base + MMCIMASK1); + mmci_set_mask1(host, 0); host->data = NULL; } @@ -162,6 +216,8 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) host->data = data; host->size = data->blksz * data->blocks; host->data_xfered = 0; + host->blockend = false; + host->dataend = false; mmci_init_sg(host, data); @@ -196,9 +252,14 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) irqmask = MCI_TXFIFOHALFEMPTYMASK; } + /* The ST Micro variants has a special bit to enable SDIO */ + if (variant->sdio && host->mmc->card) + if (mmc_card_sdio(host->mmc->card)) + datactrl |= MCI_ST_DPSM_SDIOEN; + writel(datactrl, base + MMCIDATACTRL); writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0); - writel(irqmask, base + MMCIMASK1); + mmci_set_mask1(host, irqmask); } static void @@ -233,20 +294,9 @@ static void mmci_data_irq(struct mmci_host *host, struct mmc_data *data, unsigned int status) { - if (status & MCI_DATABLOCKEND) { - host->data_xfered += data->blksz; -#ifdef CONFIG_ARCH_U300 - /* - * On the U300 some signal or other is - * badly routed so that a data write does - * not properly terminate with a MCI_DATAEND - * status flag. This quirk will make writes - * work again. - */ - if (data->flags & MMC_DATA_WRITE) - status |= MCI_DATAEND; -#endif - } + struct variant_data *variant = host->variant; + + /* First check for errors */ if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) { dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ (status %08x)\n", status); if (status & MCI_DATACRCFAIL) @@ -255,7 +305,10 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data, data->error = -ETIMEDOUT; else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN)) data->error = -EIO; - status |= MCI_DATAEND; + + /* Force-complete the transaction */ + host->blockend = true; + host->dataend = true; /* * We hit an error condition. Ensure that any data @@ -273,9 +326,64 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data, local_irq_restore(flags); } } - if (status & MCI_DATAEND) { + + /* + * On ARM variants in PIO mode, MCI_DATABLOCKEND + * is always sent first, and we increase the + * transfered number of bytes for that IRQ. Then + * MCI_DATAEND follows and we conclude the transaction. + * + * On the Ux500 single-IRQ variant MCI_DATABLOCKEND + * doesn't seem to immediately clear from the status, + * so we can't use it keep count when only one irq is + * used because the irq will hit for other reasons, and + * then the flag is still up. So we use the MCI_DATAEND + * IRQ at the end of the entire transfer because + * MCI_DATABLOCKEND is broken. + * + * In the U300, the IRQs can arrive out-of-order, + * e.g. MCI_DATABLOCKEND sometimes arrives after MCI_DATAEND, + * so for this case we use the flags "blockend" and + * "dataend" to make sure both IRQs have arrived before + * concluding the transaction. (This does not apply + * to the Ux500 which doesn't fire MCI_DATABLOCKEND + * at all.) In DMA mode it suffers from the same problem + * as the Ux500. + */ + if (status & MCI_DATABLOCKEND) { + /* + * Just being a little over-cautious, we do not + * use this progressive update if the hardware blockend + * flag is unreliable: since it can stay high between + * IRQs it will corrupt the transfer counter. + */ + if (!variant->broken_blockend) + host->data_xfered += data->blksz; + host->blockend = true; + } + + if (status & MCI_DATAEND) + host->dataend = true; + + /* + * On variants with broken blockend we shall only wait for dataend, + * on others we must sync with the blockend signal since they can + * appear out-of-order. + */ + if (host->dataend && (host->blockend || variant->broken_blockend)) { mmci_stop_data(host); + /* Reset these flags */ + host->blockend = false; + host->dataend = false; + + /* + * Variants with broken blockend flags need to handle the + * end of the entire transfer here. + */ + if (variant->broken_blockend && !data->error) + host->data_xfered += data->blksz * data->blocks; + if (!data->stop) { mmci_request_end(host, data->mrq); } else { @@ -356,7 +464,32 @@ static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int rem variant->fifosize : variant->fifohalfsize; count = min(remain, maxcnt); - writesl(base + MMCIFIFO, ptr, count >> 2); + /* + * The ST Micro variant for SDIO transfer sizes + * less then 8 bytes should have clock H/W flow + * control disabled. + */ + if (variant->sdio && + mmc_card_sdio(host->mmc->card)) { + if (count < 8) + writel(readl(host->base + MMCICLOCK) & + ~variant->clkreg_enable, + host->base + MMCICLOCK); + else + writel(readl(host->base + MMCICLOCK) | + variant->clkreg_enable, + host->base + MMCICLOCK); + } + + /* + * SDIO especially may want to send something that is + * not divisible by 4 (as opposed to card sectors + * etc), and the FIFO only accept full 32-bit writes. + * So compensate by adding +3 on the count, a single + * byte become a 32bit write, 7 bytes will be two + * 32bit writes etc. + */ + writesl(base + MMCIFIFO, ptr, (count + 3) >> 2); ptr += count; remain -= count; @@ -437,7 +570,7 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id) * "any data available" mode. */ if (status & MCI_RXACTIVE && host->size < variant->fifosize) - writel(MCI_RXDATAAVLBLMASK, base + MMCIMASK1); + mmci_set_mask1(host, MCI_RXDATAAVLBLMASK); /* * If we run out of data, disable the data IRQs; this @@ -446,7 +579,7 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id) * stops us racing with our data end IRQ. */ if (host->size == 0) { - writel(0, base + MMCIMASK1); + mmci_set_mask1(host, 0); writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0); } @@ -469,6 +602,14 @@ static irqreturn_t mmci_irq(int irq, void *dev_id) struct mmc_data *data; status = readl(host->base + MMCISTATUS); + + if (host->singleirq) { + if (status & readl(host->base + MMCIMASK1)) + mmci_pio_irq(irq, dev_id); + + status &= ~MCI_IRQ1MASK; + } + status &= readl(host->base + MMCIMASK0); writel(status, host->base + MMCICLEAR); @@ -635,6 +776,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) struct variant_data *variant = id->data; struct mmci_host *host; struct mmc_host *mmc; + unsigned int mask; int ret; /* must have platform data */ @@ -714,7 +856,6 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) mmc->f_max = min(host->mclk, fmax); dev_dbg(mmc_dev(mmc), "clocking block at %u Hz\n", mmc->f_max); -#ifdef CONFIG_REGULATOR /* If we're using the regulator framework, try to fetch a regulator */ host->vcc = regulator_get(&dev->dev, "vmmc"); if (IS_ERR(host->vcc)) @@ -733,7 +874,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) "(using regulator instead)\n"); } } -#endif + /* Fall back to platform data if no regulator is found */ if (host->vcc == NULL) mmc->ocr_avail = plat->ocr_mask; @@ -806,11 +947,21 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) if (ret) goto unmap; - ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED, DRIVER_NAME " (pio)", host); - if (ret) - goto irq0_free; + if (dev->irq[1] == NO_IRQ) + host->singleirq = true; + else { + ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED, + DRIVER_NAME " (pio)", host); + if (ret) + goto irq0_free; + } + + mask = MCI_IRQENABLE; + /* Don't use the datablockend flag if it's broken */ + if (variant->broken_blockend) + mask &= ~MCI_DATABLOCKEND; - writel(MCI_IRQENABLE, host->base + MMCIMASK0); + writel(mask, host->base + MMCIMASK0); amba_set_drvdata(dev, mmc); @@ -864,7 +1015,8 @@ static int __devexit mmci_remove(struct amba_device *dev) writel(0, host->base + MMCIDATACTRL); free_irq(dev->irq[0], host); - free_irq(dev->irq[1], host); + if (!host->singleirq) + free_irq(dev->irq[1], host); if (host->gpio_wp != -ENOSYS) gpio_free(host->gpio_wp); diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h index 4ae887fc0189..df06f01aac89 100644 --- a/drivers/mmc/host/mmci.h +++ b/drivers/mmc/host/mmci.h @@ -139,6 +139,11 @@ MCI_DATATIMEOUTMASK|MCI_TXUNDERRUNMASK|MCI_RXOVERRUNMASK| \ MCI_CMDRESPENDMASK|MCI_CMDSENTMASK|MCI_DATABLOCKENDMASK) +/* These interrupts are directed to IRQ1 when two IRQ lines are available */ +#define MCI_IRQ1MASK \ + (MCI_RXFIFOHALFFULLMASK | MCI_RXDATAAVLBLMASK | \ + MCI_TXFIFOHALFEMPTYMASK) + #define NR_SG 16 struct clk; @@ -154,6 +159,7 @@ struct mmci_host { int gpio_cd; int gpio_wp; int gpio_cd_irq; + bool singleirq; unsigned int data_xfered; @@ -171,6 +177,9 @@ struct mmci_host { struct timer_list timer; unsigned int oldstat; + bool blockend; + bool dataend; + /* pio stuff */ struct sg_mapping_iter sg_miter; unsigned int size; diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c index e4a44b641702..b0985f727078 100644 --- a/drivers/rtc/rtc-sa1100.c +++ b/drivers/rtc/rtc-sa1100.c @@ -39,7 +39,7 @@ #include <mach/regs-ost.h> #endif -#define RTC_DEF_DIVIDER 32768 - 1 +#define RTC_DEF_DIVIDER (32768 - 1) #define RTC_DEF_TRIM 0 static unsigned long rtc_freq = 1024; @@ -61,7 +61,8 @@ static inline int rtc_periodic_alarm(struct rtc_time *tm) * Calculate the next alarm time given the requested alarm time mask * and the current time. */ -static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm) +static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, + struct rtc_time *alrm) { unsigned long next_time; unsigned long now_time; @@ -116,7 +117,23 @@ static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id) rtsr = RTSR; /* clear interrupt sources */ RTSR = 0; - RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2); + /* Fix for a nasty initialization problem the in SA11xx RTSR register. + * See also the comments in sa1100_rtc_probe(). */ + if (rtsr & (RTSR_ALE | RTSR_HZE)) { + /* This is the original code, before there was the if test + * above. This code does not clear interrupts that were not + * enabled. */ + RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2); + } else { + /* For some reason, it is possible to enter this routine + * without interruptions enabled, it has been tested with + * several units (Bug in SA11xx chip?). + * + * This situation leads to an infinite "loop" of interrupt + * routine calling and as a result the processor seems to + * lock on its first call to open(). */ + RTSR = RTSR_AL | RTSR_HZ; + } /* clear alarm interrupt if it has occurred */ if (rtsr & RTSR_AL) @@ -178,7 +195,7 @@ static int sa1100_rtc_read_callback(struct device *dev, int data) * Here we compare (match - OSCR) 8 instead of 0 -- * see comment in pxa_timer_interrupt() for explanation. */ - while( (signed long)((osmr1 = OSMR1) - OSCR) <= 8 ) { + while ((signed long)((osmr1 = OSMR1) - OSCR) <= 8) { data += 0x100; OSSR = OSSR_M1; /* clear match on timer 1 */ OSMR1 = osmr1 + period; @@ -192,19 +209,19 @@ static int sa1100_rtc_open(struct device *dev) int ret; ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED, - "rtc 1Hz", dev); + "rtc 1Hz", dev); if (ret) { dev_err(dev, "IRQ %d already in use.\n", IRQ_RTC1Hz); goto fail_ui; } ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, IRQF_DISABLED, - "rtc Alrm", dev); + "rtc Alrm", dev); if (ret) { dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm); goto fail_ai; } ret = request_irq(IRQ_OST1, timer1_interrupt, IRQF_DISABLED, - "rtc timer", dev); + "rtc timer", dev); if (ret) { dev_err(dev, "IRQ %d already in use.\n", IRQ_OST1); goto fail_pi; @@ -236,7 +253,7 @@ static void sa1100_rtc_release(struct device *dev) static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { - switch(cmd) { + switch (cmd) { case RTC_AIE_OFF: spin_lock_irq(&sa1100_rtc_lock); RTSR &= ~RTSR_ALE; @@ -333,6 +350,7 @@ static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq) seq_printf(seq, "periodic_IRQ\t: %s\n", (OIER & OIER_E1) ? "yes" : "no"); seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq); + seq_printf(seq, "RTSR\t\t: 0x%08x\n", (u32)RTSR); return 0; } @@ -364,7 +382,8 @@ static int sa1100_rtc_probe(struct platform_device *pdev) */ if (RTTR == 0) { RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16); - dev_warn(&pdev->dev, "warning: initializing default clock divider/trim value\n"); + dev_warn(&pdev->dev, "warning: " + "initializing default clock divider/trim value\n"); /* The current RTC value probably doesn't make sense either */ RCNR = 0; } @@ -379,6 +398,30 @@ static int sa1100_rtc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, rtc); + /* Fix for a nasty initialization problem the in SA11xx RTSR register. + * See also the comments in sa1100_rtc_interrupt(). + * + * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an + * interrupt pending, even though interrupts were never enabled. + * In this case, this bit it must be reset before enabling + * interruptions to avoid a nonexistent interrupt to occur. + * + * In principle, the same problem would apply to bit 0, although it has + * never been observed to happen. + * + * This issue is addressed both here and in sa1100_rtc_interrupt(). + * If the issue is not addressed here, in the times when the processor + * wakes up with the bit set there will be one spurious interrupt. + * + * The issue is also dealt with in sa1100_rtc_interrupt() to be on the + * safe side, once the condition that lead to this strange + * initialization is unknown and could in principle happen during + * normal processing. + * + * Notice that clearing bit 1 and 0 is accomplished by writting ONES to + * the corresponding bits in RTSR. */ + RTSR = RTSR_AL | RTSR_HZ; + return 0; } @@ -386,7 +429,7 @@ static int sa1100_rtc_remove(struct platform_device *pdev) { struct rtc_device *rtc = platform_get_drvdata(pdev); - if (rtc) + if (rtc) rtc_device_unregister(rtc); return 0; |