OMAP2: Spi: Force CS to be in inactive state after off-mode transition
PATCH v4 1/1 OMAP2: Spi: Force CS to be in inactive state after off-mode transition
When SPI wake up from OFF mode, CS is in the wrong state: force it to the inactive state.
During the system life, I monitored the CS behavior using a oscilloscope.
I also activated debug in omap2_mcspi, so I saw when driver disable the clocks and restore context when device is not used. Each time the CS was in the correct state.
It was only when system was put suspend to ram with off-mode activated that on resume the CS was in wrong state( ie activated).
--- drivers/spi/omap2_mcspi.c | 35 +++++++++++++++++++++++++++++++++++ 1 files changed, 35 insertions(+), 0 deletions(-)
drivers/spi/omap2_mcspi.c +34 -0
@@ -1305,11 +1305,46 @@ static int __exit omap2_mcspi_remove(struct platform_device *pdev)/* work with hotplug and coldplug */ MODULE_ALIAS ("platform:omap2_mcspi" ); +#ifdef CONFIG_PM +/* When SPI wake up from off-mode, CS is in activate state. If it was in +* unactive state when driver was suspend, then force it to unactive state at +* wake up. +*/ +static int omap2_mcspi_resume (struct platform_device *pdev) +{ +struct spi_master *master; +struct omap2_mcspi_cs *cs; +struct omap2_mcspi *mcspi; + + master =dev_get_drvdata (&pdev->dev); + mcspi =spi_master_get_devdata (master); +omap2_mcspi_enable_clocks (mcspi); +list_for_each_entry (cs, &omap2_mcspi_ctx[master->bus_num -1 ].cs, + node) { +if ((cs->chconf0 &OMAP2_MCSPI_CHCONF_FORCE ) ==0 ) { + +/* We need to togle CS state for OMAP take this +* change in account. +*/ +MOD_REG_BIT (cs->chconf0,OMAP2_MCSPI_CHCONF_FORCE ,1 ); +__raw_writel (cs->chconf0, cs->base +OMAP2_MCSPI_CHCONF0 ); +MOD_REG_BIT (cs->chconf0,OMAP2_MCSPI_CHCONF_FORCE ,0 ); +__raw_writel (cs->chconf0, cs->base +OMAP2_MCSPI_CHCONF0 ); + } + } +omap2_mcspi_disable_clocks (mcspi); +return 0 ; +} +#else +#define omap2_mcspi_resume NULL +#endif +static struct platform_driver omap2_mcspi_driver = { .driver = { .name ="omap2_mcspi" , .owner =THIS_MODULE , }, + .resume = omap2_mcspi_resume, .remove =__exit_p (omap2_mcspi_remove), }; -- 1.7.0.4
Quoted 11 lines · Gregory CLEMENT
When SPI wake up from OFF mode, CS is in the wrong state: force it to the inactive state.
During the system life, I monitored the CS behavior using a oscilloscope. I also activated debug in
omap2_mcspi, so I saw when driver disable the clocks and restore context when device is not used.
Each time the CS was in the correct state.
It was only when system was put suspend to ram with off-mode activated that on resume the CS was in wrong state( ie activated).Signed-off-by Gregory CLEMENT <[email protected]>
Looks okay to me, but I'd like to get an ack from other users before I merge it. Also some minor comments below.
Quoted 15 lines
--- drivers/spi/omap2_mcspi.c | 35 +++++++++++++++++++++++++++++++++++ 1 files changed, 35 insertions(+), 0 deletions(-)drivers/spi/omap2_mcspi.c +2
-0@@ -1305,11 +1305,46 @@ static int __exit omap2_mcspi_remove(struct platform_device *pdev) /* work with hotplug and coldplug */ MODULE_ALIAS("platform:omap2_mcspi"); +#ifdef CONFIG_PM +/* When SPI wake up from off-mode, CS is in activate state. If it was in +* unactive state when driver was suspend, then force it to
Quoted 1 line
unactive state at
Patch is line-wrap damaged. Check your mailer configuration.
drivers/spi/omap2_mcspi.c static int __exit omap2_mcspi_remove(struct platform_device *pdev) · line 1319
Quoted 10 lines
+ * wake up.
+ */drivers/spi/omap2_mcspi.c +8
-0+static int omap2_mcspi_resume (struct platform_device *pdev) +{ +struct spi_master *master; +struct omap2_mcspi_cs *cs; +struct omap2_mcspi *mcspi; + + master =dev_get_drvdata (&pdev->dev); + mcspi =spi_master_get_devdata (master);
These 5 lines can be collapsed a bit:
struct spi_master *master = dev_get_drvdata(&pdev->dev); struct omap2_mcspi *mcspi = spi_master_get_devdata(master); struct omap2_mcspi_cs *cs;
drivers/spi/omap2_mcspi.c static int __exit omap2_mcspi_remove(struct platform_device *pdev) · line 1325
Quoted 6 lines
drivers/spi/omap2_mcspi.c +6
-0+omap2_mcspi_enable_clocks (mcspi); +list_for_each_entry (cs, &omap2_mcspi_ctx[master->bus_num -1 ].cs, + node) { +if ((cs->chconf0 &OMAP2_MCSPI_CHCONF_FORCE ) ==0 ) { + +/* We need to togle CS state for OMAP take this
spelling. s/togle/toggle
Quoted 25 lines
drivers/spi/omap2_mcspi.c +16
-0+* change in account. +*/ +MOD_REG_BIT (cs->chconf0,OMAP2_MCSPI_CHCONF_FORCE ,1 ); +__raw_writel (cs->chconf0, cs->base +OMAP2_MCSPI_CHCONF0 ); +MOD_REG_BIT (cs->chconf0,OMAP2_MCSPI_CHCONF_FORCE ,0 ); + __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0); + } + } +omap2_mcspi_disable_clocks (mcspi); +return 0 ; +} +#else +#define omap2_mcspi_resume NULL +#endif +static struct platform_driver omap2_mcspi_driver = { .driver = { .name ="omap2_mcspi" , .owner =THIS_MODULE , }, + .resume = omap2_mcspi_resume, .remove =__exit_p (omap2_mcspi_remove), }; -- 1.7.0.4