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121 lines
4.3 KiB
Diff
121 lines
4.3 KiB
Diff
From 6d8e14dc4253f3921aff1bbbeb3caf073aa6a7b2 Mon Sep 17 00:00:00 2001
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From: Andy Green <andy@openmoko.com>
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Date: Wed, 30 Jul 2008 12:46:44 +0100
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Subject: [PATCH] add-glamo-mci-slower-clocking-dynamic-switching.patch
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This patch gives glamo-mci a concept of a platform-defined
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dynamic clock slowing callback. It means that platform code
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can associate some completely external state to decide if
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we run the SD clock at normal rate or a rate divided by a
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module parameter "sd_slow_ratio", which you can set on
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kernel commandline like this:
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glamo_mci.sd_slow_ratio=8
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you can also change it at runtime by
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echo 8 > /sys/module/glamo_mci/parameters/sd_slow_ratio
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If no platform callback is defined, then no slow mode
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is used. If it is defined, then the default division
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action is / 8, eg, 16MHz normal -> 2MHz slow mode.
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Signed-off-by: Andy Green <andy@openmoko.com>
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---
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drivers/mfd/glamo/glamo-core.c | 2 ++
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drivers/mfd/glamo/glamo-core.h | 2 ++
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drivers/mfd/glamo/glamo-mci.c | 30 ++++++++++++++++++++++++++++--
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include/linux/glamofb.h | 2 ++
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4 files changed, 34 insertions(+), 2 deletions(-)
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diff --git a/drivers/mfd/glamo/glamo-core.c b/drivers/mfd/glamo/glamo-core.c
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index f411446..c094a8c 100644
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--- a/drivers/mfd/glamo/glamo-core.c
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+++ b/drivers/mfd/glamo/glamo-core.c
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@@ -1114,6 +1114,8 @@ static int __init glamo_probe(struct platform_device *pdev)
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/* bring MCI specific stuff over from our MFD platform data */
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glamo_mci_def_pdata.glamo_set_mci_power =
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glamo->pdata->glamo_set_mci_power;
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+ glamo_mci_def_pdata.glamo_mci_use_slow =
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+ glamo->pdata->glamo_mci_use_slow;
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glamo_mci_def_pdata.glamo_irq_is_wired =
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glamo->pdata->glamo_irq_is_wired;
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glamo_mci_def_pdata.mci_suspending =
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diff --git a/drivers/mfd/glamo/glamo-core.h b/drivers/mfd/glamo/glamo-core.h
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index 8d647ec..d3f4309 100644
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--- a/drivers/mfd/glamo/glamo-core.h
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+++ b/drivers/mfd/glamo/glamo-core.h
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@@ -72,6 +72,8 @@ struct glamo_mci_pdata {
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unsigned long ocr_avail;
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void (*glamo_set_mci_power)(unsigned char power_mode,
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unsigned short vdd);
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+ /* glamo-mci asking if it should use the slow clock to card */
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+ int (*glamo_mci_use_slow)(void);
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int (*glamo_irq_is_wired)(void);
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void (*mci_suspending)(struct platform_device *dev);
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int (*mci_all_dependencies_resumed)(struct platform_device
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diff --git a/drivers/mfd/glamo/glamo-mci.c b/drivers/mfd/glamo/glamo-mci.c
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index 54ba613..577021e 100644
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--- a/drivers/mfd/glamo/glamo-mci.c
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+++ b/drivers/mfd/glamo/glamo-mci.c
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@@ -57,6 +57,23 @@ static int sd_max_clk = 50000000 / 3;
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module_param(sd_max_clk, int, 0644);
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/*
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+ * Slow SD clock rate
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+ *
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+ * you can override this on kernel commandline using
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+ *
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+ * glamo_mci.sd_slow_ratio=8
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+ *
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+ * for example
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+ *
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+ * platform callback is used to decide effective clock rate, if not
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+ * defined then max is used, if defined and returns nonzero, rate is
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+ * divided by this factor
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+ */
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+
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+static int sd_slow_ratio = 8;
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+module_param(sd_slow_ratio, int, 0644);
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+
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+/*
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* SD Signal drive strength
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*
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* you can override this on kernel commandline using
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@@ -554,8 +571,17 @@ static void glamo_mci_send_request(struct mmc_host *mmc)
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cmd->opcode, cmd->arg, cmd->data, cmd->mrq->stop,
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cmd->flags);
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- /* resume requested clock rate */
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- __glamo_mci_fix_card_div(host, host->clk_div);
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+ /* resume requested clock rate
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+ * scale it down by sd_slow_ratio if platform requests it
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+ */
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+ if (host->pdata->glamo_mci_use_slow)
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+ if ((host->pdata->glamo_mci_use_slow)())
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+ __glamo_mci_fix_card_div(host, host->clk_div *
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+ sd_slow_ratio);
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+ else
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+ __glamo_mci_fix_card_div(host, host->clk_div);
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+ else
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+ __glamo_mci_fix_card_div(host, host->clk_div);
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if (glamo_mci_send_command(host, cmd))
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goto bail;
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diff --git a/include/linux/glamofb.h b/include/linux/glamofb.h
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index efd315b..b101e9c 100644
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--- a/include/linux/glamofb.h
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+++ b/include/linux/glamofb.h
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@@ -31,6 +31,8 @@ struct glamofb_platform_data {
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/* glamo mmc platform specific info */
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void (*glamo_set_mci_power)(unsigned char power_mode,
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unsigned short vdd);
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+ /* glamo-mci asking if it should use the slow clock to card */
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+ int (*glamo_mci_use_slow)(void);
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int (*glamo_irq_is_wired)(void);
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void (*mci_suspending)(struct platform_device *dev);
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int (*mci_all_dependencies_resumed)(struct platform_device
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--
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1.5.6.5
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