kernel: update linux 3.2 to 3.2.14
[openwrt/svn-archive/archive.git] / target / linux / xburst / patches-3.2 / 0013-MMC-JZ4740-Added-support-for-CPU-frequency-changing.patch
1 From b95144c1b702f98c7902c75beb83f323701eb7c5 Mon Sep 17 00:00:00 2001
2 From: Maarten ter Huurne <maarten@treewalker.org>
3 Date: Sun, 19 Jun 2011 10:57:18 +0200
4 Subject: [PATCH 13/21] MMC: JZ4740: Added support for CPU frequency changing.
5
6 The MSC device clock is stopped before the frequency change.
7 After the change a new divider is computed and the clock is restarted.
8 Also the frequency change is postponed if an I/O operation is in progress.
9 ---
10 drivers/mmc/host/jz4740_mmc.c | 69 +++++++++++++++++++++++++++++++++++++++-
11 1 files changed, 67 insertions(+), 2 deletions(-)
12
13 --- a/drivers/mmc/host/jz4740_mmc.c
14 +++ b/drivers/mmc/host/jz4740_mmc.c
15 @@ -23,6 +23,7 @@
16 #include <linux/delay.h>
17 #include <linux/scatterlist.h>
18 #include <linux/clk.h>
19 +#include <linux/cpufreq.h>
20
21 #include <linux/bitops.h>
22 #include <linux/gpio.h>
23 @@ -685,6 +686,60 @@ static void jz4740_mmc_enable_sdio_irq(s
24 jz4740_mmc_set_irq_enabled(host, JZ_MMC_IRQ_SDIO, enable);
25 }
26
27 +#ifdef CONFIG_CPU_FREQ
28 +
29 +static struct jz4740_mmc_host *cpufreq_host;
30 +
31 +static int jz4740_mmc_cpufreq_transition(struct notifier_block *nb,
32 + unsigned long val, void *data)
33 +{
34 + /* TODO: We only have to take action when the PLL freq changes:
35 + the main dividers have no influence on the MSC device clock. */
36 +
37 + if (val == CPUFREQ_PRECHANGE) {
38 + mmc_claim_host(cpufreq_host->mmc);
39 + clk_disable(cpufreq_host->clk);
40 + } else if (val == CPUFREQ_POSTCHANGE) {
41 + struct mmc_ios *ios = &cpufreq_host->mmc->ios;
42 + if (ios->clock)
43 + jz4740_mmc_set_clock_rate(cpufreq_host, ios->clock);
44 + if (ios->power_mode != MMC_POWER_OFF)
45 + clk_enable(cpufreq_host->clk);
46 + mmc_release_host(cpufreq_host->mmc);
47 + }
48 + return 0;
49 +}
50 +
51 +static struct notifier_block jz4740_mmc_cpufreq_nb = {
52 + .notifier_call = jz4740_mmc_cpufreq_transition,
53 +};
54 +
55 +static inline int jz4740_mmc_cpufreq_register(struct jz4740_mmc_host *host)
56 +{
57 + cpufreq_host = host;
58 + return cpufreq_register_notifier(&jz4740_mmc_cpufreq_nb,
59 + CPUFREQ_TRANSITION_NOTIFIER);
60 +}
61 +
62 +static inline void jz4740_mmc_cpufreq_unregister(void)
63 +{
64 + cpufreq_unregister_notifier(&jz4740_mmc_cpufreq_nb,
65 + CPUFREQ_TRANSITION_NOTIFIER);
66 +}
67 +
68 +#else
69 +
70 +static inline int jz4740_mmc_cpufreq_register(struct jz4740_mmc_host *host)
71 +{
72 + return 0;
73 +}
74 +
75 +static inline void jz4740_mmc_cpufreq_unregister(void)
76 +{
77 +}
78 +
79 +#endif
80 +
81 static const struct mmc_host_ops jz4740_mmc_ops = {
82 .request = jz4740_mmc_request,
83 .set_ios = jz4740_mmc_set_ios,
84 @@ -834,11 +889,18 @@ static int __devinit jz4740_mmc_probe(st
85 goto err_free_host;
86 }
87
88 + ret = jz4740_mmc_cpufreq_register(host);
89 + if (ret) {
90 + dev_err(&pdev->dev,
91 + "Failed to register cpufreq transition notifier\n");
92 + goto err_clk_put;
93 + }
94 +
95 host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
96 if (!host->mem) {
97 ret = -ENOENT;
98 dev_err(&pdev->dev, "Failed to get base platform memory\n");
99 - goto err_clk_put;
100 + goto err_cpufreq_unreg;
101 }
102
103 host->mem = request_mem_region(host->mem->start,
104 @@ -846,7 +908,7 @@ static int __devinit jz4740_mmc_probe(st
105 if (!host->mem) {
106 ret = -EBUSY;
107 dev_err(&pdev->dev, "Failed to request base memory region\n");
108 - goto err_clk_put;
109 + goto err_cpufreq_unreg;
110 }
111
112 host->base = ioremap_nocache(host->mem->start, resource_size(host->mem));
113 @@ -929,6 +991,8 @@ err_iounmap:
114 iounmap(host->base);
115 err_release_mem_region:
116 release_mem_region(host->mem->start, resource_size(host->mem));
117 +err_cpufreq_unreg:
118 + jz4740_mmc_cpufreq_unregister();
119 err_clk_put:
120 clk_put(host->clk);
121 err_free_host:
122 @@ -958,6 +1022,7 @@ static int __devexit jz4740_mmc_remove(s
123 iounmap(host->base);
124 release_mem_region(host->mem->start, resource_size(host->mem));
125
126 + jz4740_mmc_cpufreq_unregister();
127 clk_put(host->clk);
128
129 platform_set_drvdata(pdev, NULL);