From: Magnus Damm <damm@xxxxxxxxxx>
This patch modifies the SuperH Mobile LCDC framebuffer driver
to support Runtime PM. The driver is using the functions
- pm_runtime_get_sync()
- pm_runtime_put_sync()
to inform the bus code if the hardware is idle or not. If the
hardware is idle then the bus code may call the runtime dev_pm_ops
callbacks to save and restore state. pm_runtime_resume() is used
to allow the driver to access the hardware from probe().
Signed-off-by: Magnus Damm <damm@xxxxxxxxxx>
---
Changes since V2:
- implemented proper device register save and restore
- use pm_runtime_resume() to support probe() hardware usage
Changes since V1:
- use pm_runtime_get_sync() and pm_runtime_put_sync()
- use pm_runtime_disable()
- no need for pm_runtime_set_suspended()
- incomplete runtime pm functions for dev_pm_ops
- work around with pm_runtime_put_noidle()/pm_runtime_get_noresume()
drivers/video/sh_mobile_lcdcfb.c | 154 ++++++++++++++++++++++++++------------
1 file changed, 109 insertions(+), 45 deletions(-)
--- 0001/drivers/video/sh_mobile_lcdcfb.c
+++ work/drivers/video/sh_mobile_lcdcfb.c 2009-08-11 19:54:43.000000000 +0900
@@ -14,6 +14,7 @@
#include <linux/mm.h>
#include <linux/fb.h>
#include <linux/clk.h>
+#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
@@ -23,33 +24,6 @@
#define PALETTE_NR 16
-struct sh_mobile_lcdc_priv;
-struct sh_mobile_lcdc_chan {
- struct sh_mobile_lcdc_priv *lcdc;
- unsigned long *reg_offs;
- unsigned long ldmt1r_value;
- unsigned long enabled; /* ME and SE in LDCNT2R */
- struct sh_mobile_lcdc_chan_cfg cfg;
- u32 pseudo_palette[PALETTE_NR];
- struct fb_info *info;
- dma_addr_t dma_handle;
- struct fb_deferred_io defio;
- struct scatterlist *sglist;
- unsigned long frame_end;
- wait_queue_head_t frame_end_wait;
-};
-
-struct sh_mobile_lcdc_priv {
- void __iomem *base;
- int irq;
- atomic_t clk_usecnt;
- struct clk *dot_clk;
- struct clk *clk;
- unsigned long lddckr;
- struct sh_mobile_lcdc_chan ch[2];
- int started;
-};
-
/* shared registers */
#define _LDDCKR 0x410
#define _LDDCKSTPR 0x414
@@ -63,11 +37,23 @@ struct sh_mobile_lcdc_priv {
#define _LDDWAR 0x900
#define _LDDRAR 0x904
+/* shared registers and their order for context save/restore */
+static int lcdc_shared_regs[] = {
+ _LDDCKR,
+ _LDDCKSTPR,
+ _LDINTR,
+ _LDDDSR,
+ _LDCNT1R,
+ _LDCNT2R,
+};
+#define NR_SHARED_REGS ARRAY_SIZE(lcdc_shared_regs)
+
/* per-channel registers */
enum { LDDCKPAT1R, LDDCKPAT2R, LDMT1R, LDMT2R, LDMT3R, LDDFR, LDSM1R,
- LDSM2R, LDSA1R, LDMLSR, LDHCNR, LDHSYNR, LDVLNR, LDVSYNR, LDPMR };
+ LDSM2R, LDSA1R, LDMLSR, LDHCNR, LDHSYNR, LDVLNR, LDVSYNR, LDPMR,
+ NR_CH_REGS };
-static unsigned long lcdc_offs_mainlcd[] = {
+static unsigned long lcdc_offs_mainlcd[NR_CH_REGS] = {
[LDDCKPAT1R] = 0x400,
[LDDCKPAT2R] = 0x404,
[LDMT1R] = 0x418,
@@ -85,7 +71,7 @@ static unsigned long lcdc_offs_mainlcd[]
[LDPMR] = 0x460,
};
-static unsigned long lcdc_offs_sublcd[] = {
+static unsigned long lcdc_offs_sublcd[NR_CH_REGS] = {
[LDDCKPAT1R] = 0x408,
[LDDCKPAT2R] = 0x40c,
[LDMT1R] = 0x600,
@@ -110,6 +96,35 @@ static unsigned long lcdc_offs_sublcd[]
#define LDINTR_FE 0x00000400
#define LDINTR_FS 0x00000004
+struct sh_mobile_lcdc_priv;
+struct sh_mobile_lcdc_chan {
+ struct sh_mobile_lcdc_priv *lcdc;
+ unsigned long *reg_offs;
+ unsigned long ldmt1r_value;
+ unsigned long enabled; /* ME and SE in LDCNT2R */
+ struct sh_mobile_lcdc_chan_cfg cfg;
+ u32 pseudo_palette[PALETTE_NR];
+ unsigned long saved_ch_regs[NR_CH_REGS];
+ struct fb_info *info;
+ dma_addr_t dma_handle;
+ struct fb_deferred_io defio;
+ struct scatterlist *sglist;
+ unsigned long frame_end;
+ wait_queue_head_t frame_end_wait;
+};
+
+struct sh_mobile_lcdc_priv {
+ void __iomem *base;
+ int irq;
+ atomic_t hw_usecnt;
+ struct device *dev;
+ struct clk *dot_clk;
+ unsigned long lddckr;
+ struct sh_mobile_lcdc_chan ch[2];
+ unsigned long saved_shared_regs[NR_SHARED_REGS];
+ int started;
+};
+
static void lcdc_write_chan(struct sh_mobile_lcdc_chan *chan,
int reg_nr, unsigned long data)
{
@@ -188,8 +203,8 @@ struct sh_mobile_lcdc_sys_bus_ops sh_mob
static void sh_mobile_lcdc_clk_on(struct sh_mobile_lcdc_priv *priv)
{
- if (atomic_inc_and_test(&priv->clk_usecnt)) {
- clk_enable(priv->clk);
+ if (atomic_inc_and_test(&priv->hw_usecnt)) {
+ pm_runtime_get_sync(priv->dev);
if (priv->dot_clk)
clk_enable(priv->dot_clk);
}
@@ -197,10 +212,10 @@ static void sh_mobile_lcdc_clk_on(struct
static void sh_mobile_lcdc_clk_off(struct sh_mobile_lcdc_priv *priv)
{
- if (atomic_sub_return(1, &priv->clk_usecnt) == -1) {
+ if (atomic_sub_return(1, &priv->hw_usecnt) == -1) {
if (priv->dot_clk)
clk_disable(priv->dot_clk);
- clk_disable(priv->clk);
+ pm_runtime_put(priv->dev);
}
}
@@ -569,7 +584,6 @@ static int sh_mobile_lcdc_setup_clocks(s
int clock_source,
struct sh_mobile_lcdc_priv *priv)
{
- char clk_name[8];
char *str;
int icksel;
@@ -583,23 +597,21 @@ static int sh_mobile_lcdc_setup_clocks(s
priv->lddckr = icksel << 16;
- atomic_set(&priv->clk_usecnt, -1);
- snprintf(clk_name, sizeof(clk_name), "lcdc%d", pdev->id);
- priv->clk = clk_get(&pdev->dev, clk_name);
- if (IS_ERR(priv->clk)) {
- dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name);
- return PTR_ERR(priv->clk);
- }
-
if (str) {
priv->dot_clk = clk_get(&pdev->dev, str);
if (IS_ERR(priv->dot_clk)) {
dev_err(&pdev->dev, "cannot get dot clock %s\n", str);
- clk_put(priv->clk);
return PTR_ERR(priv->dot_clk);
}
}
+ atomic_set(&priv->hw_usecnt, -1);
+ /* Runtime PM support involves two step for this driver:
+ * 1) Enable Runtime PM
+ * 2) Force Runtime PM Resume since hardware is accessed from probe()
+ */
+ pm_runtime_enable(priv->dev);
+ pm_runtime_resume(priv->dev);
return 0;
}
@@ -717,9 +729,59 @@ static int sh_mobile_lcdc_resume(struct
return sh_mobile_lcdc_start(platform_get_drvdata(pdev));
}
+static int sh_mobile_lcdc_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct sh_mobile_lcdc_priv *p = platform_get_drvdata(pdev);
+ struct sh_mobile_lcdc_chan *ch;
+ int k, n;
+
+ /* save per-channel registers */
+ for (k = 0; k < ARRAY_SIZE(p->ch); k++) {
+ ch = &p->ch[k];
+ if (!ch->enabled)
+ continue;
+ for (n = 0; n < NR_CH_REGS; n++)
+ ch->saved_ch_regs[n] = lcdc_read_chan(ch, n);
+ }
+
+ /* save shared registers */
+ for (n = 0; n < NR_SHARED_REGS; n++)
+ p->saved_shared_regs[n] = lcdc_read(p, lcdc_shared_regs[n]);
+
+ /* turn off LCDC hardware */
+ lcdc_write(p, _LDCNT1R, 0);
+ return 0;
+}
+
+static int sh_mobile_lcdc_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct sh_mobile_lcdc_priv *p = platform_get_drvdata(pdev);
+ struct sh_mobile_lcdc_chan *ch;
+ int k, n;
+
+ /* restore per-channel registers */
+ for (k = 0; k < ARRAY_SIZE(p->ch); k++) {
+ ch = &p->ch[k];
+ if (!ch->enabled)
+ continue;
+ for (n = 0; n < NR_CH_REGS; n++)
+ lcdc_write_chan(ch, n, ch->saved_ch_regs[n]);
+ }
+
+ /* restore shared registers */
+ for (n = 0; n < NR_SHARED_REGS; n++)
+ lcdc_write(p, lcdc_shared_regs[n], p->saved_shared_regs[n]);
+
+ return 0;
+}
+
static struct dev_pm_ops sh_mobile_lcdc_dev_pm_ops = {
.suspend = sh_mobile_lcdc_suspend,
.resume = sh_mobile_lcdc_resume,
+ .runtime_suspend = sh_mobile_lcdc_runtime_suspend,
+ .runtime_resume = sh_mobile_lcdc_runtime_resume,
};
static int sh_mobile_lcdc_remove(struct platform_device *pdev);
@@ -764,6 +826,7 @@ static int __init sh_mobile_lcdc_probe(s
}
priv->irq = i;
+ priv->dev = &pdev->dev;
platform_set_drvdata(pdev, priv);
pdata = pdev->dev.platform_data;
@@ -935,7 +998,8 @@ static int sh_mobile_lcdc_remove(struct
if (priv->dot_clk)
clk_put(priv->dot_clk);
- clk_put(priv->clk);
+
+ pm_runtime_disable(priv->dev);
if (priv->base)
iounmap(priv->base);
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