diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0217-bcm2835-sdhost-Adjust-to-core-clock-changes.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0217-bcm2835-sdhost-Adjust-to-core-clock-changes.patch | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0217-bcm2835-sdhost-Adjust-to-core-clock-changes.patch b/target/linux/brcm2708/patches-4.4/0217-bcm2835-sdhost-Adjust-to-core-clock-changes.patch new file mode 100644 index 0000000000..f671944f15 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0217-bcm2835-sdhost-Adjust-to-core-clock-changes.patch @@ -0,0 +1,339 @@ +From 4b89d07fd299a0f4e25321920cb74416ba2e638e Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Wed, 30 Mar 2016 16:33:09 +0100 +Subject: [PATCH 217/232] bcm2835-sdhost: Adjust to core clock changes + +The SDHOST block uses the core clock, so previously it has been +necessary to prevent the core clock from changing in order to maintain +performance and prevent accidental SD bus overclocking. + +With this patch the sdhost driver is notified of clock changes, allowing +it to delay them while an SD access is outstanding and to delay new SD +accesses while the clock is changing. This feature is disabled in the +case where the core frequency can never change. + +Now that the driver copes with changes to the core clock, it is safe +to disable the io_is_busy feature of the on-demand governor. + +Signed-off-by: Phil Elwell <phil@raspberrypi.org> +--- + drivers/mmc/host/Kconfig | 1 + + drivers/mmc/host/bcm2835-sdhost.c | 140 ++++++++++++++++++++++++++++++++------ + 2 files changed, 119 insertions(+), 22 deletions(-) + +--- a/drivers/mmc/host/Kconfig ++++ b/drivers/mmc/host/Kconfig +@@ -36,6 +36,7 @@ config MMC_BCM2835_PIO_DMA_BARRIER + config MMC_BCM2835_SDHOST + tristate "Support for the SDHost controller on BCM2708/9" + depends on MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835 ++ depends on RASPBERRYPI_FIRMWARE + help + This selects the SDHost controller on BCM2835/6. + +--- a/drivers/mmc/host/bcm2835-sdhost.c ++++ b/drivers/mmc/host/bcm2835-sdhost.c +@@ -50,6 +50,10 @@ + #include <linux/of_dma.h> + #include <linux/time.h> + #include <linux/workqueue.h> ++#include <linux/cpufreq.h> ++#include <linux/semaphore.h> ++#include <soc/bcm2835/raspberrypi-firmware.h> ++ + + #define DRIVER_NAME "sdhost-bcm2835" + +@@ -136,6 +140,8 @@ + + #define MHZ 1000000 + ++#define RPI_FIRMWARE_CLOCK_CORE 4 ++ + + struct bcm2835_host { + spinlock_t lock; +@@ -151,7 +157,9 @@ struct bcm2835_host { + + bool slow_card; /* Force 11-bit divisor */ + +- unsigned int max_clk; /* Max possible freq */ ++ unsigned int max_clk; /* Max src clock freq */ ++ unsigned int min_clk; /* Min src clock freq */ ++ unsigned int cur_clk; /* Current src clock freq */ + + struct tasklet_struct finish_tasklet; /* Tasklet structures */ + +@@ -183,6 +191,7 @@ struct bcm2835_host { + unsigned int use_sbc:1; /* Send CMD23 */ + + unsigned int debug:1; /* Enable debug output */ ++ unsigned int variable_clock:1; /* The core clock may change */ + + /*DMA part*/ + struct dma_chan *dma_chan_rxtx; /* DMA channel for reads and writes */ +@@ -208,6 +217,9 @@ struct bcm2835_host { + u32 pio_limit; /* Maximum block count for PIO (0 = always DMA) */ + + u32 sectors; /* Cached card size in sectors */ ++ ++ struct notifier_block cpufreq_nb; /* The cpufreq callback list item */ ++ struct semaphore cpufreq_semaphore; /* Interlock between SD activity and cpufreq changes */ + }; + + #if ENABLE_LOG +@@ -227,6 +239,10 @@ static u32 sdhost_log_idx; + static spinlock_t log_lock; + static void __iomem *timer_base; + ++static int bcm2835_sdhost_cpufreq_callback(struct notifier_block *nb, ++ unsigned long action, void *data); ++static unsigned int get_core_clock(unsigned int mode); ++ + #define LOG_ENTRIES (256*1) + #define LOG_SIZE (sizeof(LOG_ENTRY_T)*LOG_ENTRIES) + +@@ -448,20 +464,14 @@ static void bcm2835_sdhost_reset(struct + + static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios); + +-static void bcm2835_sdhost_init(struct bcm2835_host *host, int soft) ++static void bcm2835_sdhost_init(struct bcm2835_host *host) + { +- pr_debug("bcm2835_sdhost_init(%d)\n", soft); ++ pr_debug("bcm2835_sdhost_init()\n"); + + /* Set interrupt enables */ + host->hcfg = SDHCFG_BUSY_IRPT_EN; + + bcm2835_sdhost_reset_internal(host); +- +- if (soft) { +- /* force clock reconfiguration */ +- host->clock = 0; +- bcm2835_sdhost_set_ios(host->mmc, &host->mmc->ios); +- } + } + + static void bcm2835_sdhost_wait_transfer_complete(struct bcm2835_host *host) +@@ -1499,10 +1509,10 @@ static irqreturn_t bcm2835_sdhost_irq(in + return result; + } + +-void bcm2835_sdhost_set_clock(struct bcm2835_host *host, unsigned int clock) ++void bcm2835_sdhost_set_clock(struct bcm2835_host *host) + { + int div = 0; /* Initialized for compiler warning */ +- unsigned int input_clock = clock; ++ unsigned int clock = host->clock; + + if (host->debug) + pr_info("%s: set_clock(%d)\n", mmc_hostname(host->mmc), clock); +@@ -1543,17 +1553,17 @@ void bcm2835_sdhost_set_clock(struct bcm + return; + } + +- div = host->max_clk / clock; ++ div = host->cur_clk / clock; + if (div < 2) + div = 2; +- if ((host->max_clk / div) > clock) ++ if ((host->cur_clk / div) > clock) + div++; + div -= 2; + + if (div > SDCDIV_MAX_CDIV) + div = SDCDIV_MAX_CDIV; + +- clock = host->max_clk / (div + 2); ++ clock = host->cur_clk / (div + 2); + host->mmc->actual_clock = clock; + + /* Calibrate some delays */ +@@ -1561,7 +1571,7 @@ void bcm2835_sdhost_set_clock(struct bcm + host->ns_per_fifo_word = (1000000000/clock) * + ((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32); + +- if (clock > input_clock) { ++ if (clock > host->clock) { + /* Save the closest value, to make it easier + to reduce in the event of error */ + host->overclock_50 = (clock/MHZ); +@@ -1587,9 +1597,9 @@ void bcm2835_sdhost_set_clock(struct bcm + bcm2835_sdhost_write(host, host->mmc->actual_clock/2, SDTOUT); + + if (host->debug) +- pr_info("%s: clock=%d -> max_clk=%d, cdiv=%x (actual clock %d)\n", +- mmc_hostname(host->mmc), input_clock, +- host->max_clk, host->cdiv, host->mmc->actual_clock); ++ pr_info("%s: clock=%d -> cur_clk=%d, cdiv=%x (actual clock %d)\n", ++ mmc_hostname(host->mmc), host->clock, ++ host->cur_clk, host->cdiv, host->mmc->actual_clock); + } + + static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq) +@@ -1638,6 +1648,13 @@ static void bcm2835_sdhost_request(struc + (mrq->data->blocks > host->pio_limit)) + bcm2835_sdhost_prepare_dma(host, mrq->data); + ++ if (host->variable_clock && ++ (down_killable(&host->cpufreq_semaphore) != 0)) { ++ mrq->cmd->error = -EINTR; ++ mmc_request_done(mmc, mrq); ++ return; ++ } ++ + spin_lock_irqsave(&host->lock, flags); + + WARN_ON(host->mrq != NULL); +@@ -1687,6 +1704,52 @@ static void bcm2835_sdhost_request(struc + spin_unlock_irqrestore(&host->lock, flags); + } + ++static int bcm2835_sdhost_cpufreq_callback(struct notifier_block *nb, ++ unsigned long action, void *data) ++{ ++ struct cpufreq_freqs *freq = data; ++ struct bcm2835_host *host; ++ ++ host = container_of(nb, struct bcm2835_host, cpufreq_nb); ++ ++ if (freq->cpu == 0) { ++ switch (action) { ++ case CPUFREQ_PRECHANGE: ++ if (down_killable(&host->cpufreq_semaphore) != 0) ++ return NOTIFY_BAD; ++ break; ++ case CPUFREQ_POSTCHANGE: ++ if (freq->new > freq->old) ++ host->cur_clk = host->max_clk; ++ else ++ host->cur_clk = host->min_clk; ++ bcm2835_sdhost_set_clock(host); ++ up(&host->cpufreq_semaphore); ++ break; ++ default: ++ break; ++ } ++ } ++ return NOTIFY_OK; ++} ++ ++static unsigned int get_core_clock(unsigned int mode) ++{ ++ struct rpi_firmware *fw = rpi_firmware_get(NULL); ++ struct { ++ u32 id; ++ u32 val; ++ } packet; ++ int ret; ++ ++ packet.id = RPI_FIRMWARE_CLOCK_CORE; ++ ret = rpi_firmware_property(fw, mode, &packet, sizeof(packet)); ++ if (ret) ++ return 0; ++ ++ return packet.val; ++} ++ + static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) + { + +@@ -1700,13 +1763,16 @@ static void bcm2835_sdhost_set_ios(struc + ios->clock, ios->power_mode, ios->bus_width, + ios->timing, ios->signal_voltage, ios->drv_type); + ++ if (ios->clock && !host->cur_clk) ++ host->cur_clk = get_core_clock(RPI_FIRMWARE_GET_CLOCK_RATE); ++ + spin_lock_irqsave(&host->lock, flags); + + log_event("IOS<", ios->clock, 0); + + if (!ios->clock || ios->clock != host->clock) { +- bcm2835_sdhost_set_clock(host, ios->clock); + host->clock = ios->clock; ++ bcm2835_sdhost_set_clock(host); + } + + /* set bus width */ +@@ -1795,7 +1861,7 @@ static void bcm2835_sdhost_tasklet_finis + host->overclock_50--; + pr_warn("%s: reducing overclock due to errors\n", + mmc_hostname(host->mmc)); +- bcm2835_sdhost_set_clock(host,50*MHZ); ++ bcm2835_sdhost_set_clock(host); + mrq->cmd->error = -EILSEQ; + mrq->cmd->retries = 1; + } +@@ -1813,6 +1879,9 @@ static void bcm2835_sdhost_tasklet_finis + + spin_unlock_irqrestore(&host->lock, flags); + ++ if (host->variable_clock) ++ up(&host->cpufreq_semaphore); ++ + if (terminate_chan) + { + int err = dmaengine_terminate_all(terminate_chan); +@@ -1915,10 +1984,10 @@ int bcm2835_sdhost_add_host(struct bcm28 + setup_timer(&host->timer, bcm2835_sdhost_timeout, + (unsigned long)host); + +- bcm2835_sdhost_init(host, 0); ++ bcm2835_sdhost_init(host); + + ret = request_irq(host->irq, bcm2835_sdhost_irq, 0 /*IRQF_SHARED*/, +- mmc_hostname(mmc), host); ++ mmc_hostname(mmc), host); + if (ret) { + pr_err("%s: failed to request IRQ %d: %d\n", + mmc_hostname(mmc), host->irq, ret); +@@ -1953,6 +2022,7 @@ static int bcm2835_sdhost_probe(struct p + struct bcm2835_host *host; + struct mmc_host *mmc; + const __be32 *addr; ++ unsigned int max_clk; + int ret; + + pr_debug("bcm2835_sdhost_probe\n"); +@@ -2062,6 +2132,28 @@ static int bcm2835_sdhost_probe(struct p + if (ret) + goto err; + ++ /* Query the core clock frequencies */ ++ host->min_clk = get_core_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE); ++ max_clk = get_core_clock(RPI_FIRMWARE_GET_MAX_CLOCK_RATE); ++ if (max_clk != host->max_clk) { ++ pr_warn("%s: Expected max clock %d, found %d\n", ++ mmc_hostname(mmc), host->max_clk, max_clk); ++ host->max_clk = max_clk; ++ } ++ ++ if (host->min_clk != host->max_clk) { ++ host->cpufreq_nb.notifier_call = ++ bcm2835_sdhost_cpufreq_callback; ++ sema_init(&host->cpufreq_semaphore, 1); ++ cpufreq_register_notifier(&host->cpufreq_nb, ++ CPUFREQ_TRANSITION_NOTIFIER); ++ host->variable_clock = 1; ++ host->cur_clk = 0; /* Get this later */ ++ } else { ++ host->variable_clock = 0; ++ host->cur_clk = host->max_clk; ++ } ++ + platform_set_drvdata(pdev, host); + + pr_debug("bcm2835_sdhost_probe -> OK\n"); +@@ -2081,6 +2173,10 @@ static int bcm2835_sdhost_remove(struct + + pr_debug("bcm2835_sdhost_remove\n"); + ++ if (host->variable_clock) ++ cpufreq_unregister_notifier(&host->cpufreq_nb, ++ CPUFREQ_TRANSITION_NOTIFIER); ++ + mmc_remove_host(host->mmc); + + bcm2835_sdhost_set_power(host, false); |