Subject: [PATCH 3/3] ARM: imx: enable RBC to support anatop LPM mode

From: [email-masked] (Anson Huang)
Date: Wed, 20 Mar 2013 18:06:53 -0400

On Wed, Mar 20, 2013 at 05:01:19PM +0800, Shawn Guo wrote:
> On Wed, Mar 20, 2013 at 01:39:40PM -0400, Anson Huang wrote:
> > RBC is to control whether some ANATOP sub modules
> > can enter lpm mode when SOC is into STOP mode, if
> > RBC is enabled and PMIC_VSTBY_REQ is set, ANATOP
> > will have below behaviors:
> > 
> > 1. Digital LDOs(CORE, SOC and PU) are bypassed;
> > 2. Analog LDOs(1P1, 2P5, 3P0) are disabled;
> > 
> > As the 2P5 is necessary for DRAM IO pre-drive in
> > STOP mode, so we need to enable weak 2P5 in STOP
> > mode when 2P5 LDO is disabled.
> > 
> > For RBC settings, there are some rules as below
> > due to hardware designe:
> 
> s/designe/design
Accepted.
> 
> > 
> > 1. All interrupts must be masked during operating
> >    RBC registers;
> > 2. At least 2 CKIL(32K) cycles is needed after the
> >    RBC setting is changed.
> > 
> > Signed-off-by: Anson Huang <[email-masked]>
> > ---
> >  arch/arm/mach-imx/anatop.c    |   19 +++++++++++++++++++
> >  arch/arm/mach-imx/clk-imx6q.c |   35 +++++++++++++++++++++++++++++++++++
> >  arch/arm/mach-imx/common.h    |    3 +++
> >  arch/arm/mach-imx/gpc.c       |   21 ++++++++++++++++++++-
> >  arch/arm/mach-imx/pm-imx6q.c  |    2 ++
> >  5 files changed, 79 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm/mach-imx/anatop.c b/arch/arm/mach-imx/anatop.c
> > index 8f6ab27..38b4f44 100644
> > --- a/arch/arm/mach-imx/anatop.c
> > +++ b/arch/arm/mach-imx/anatop.c
> > @@ -18,12 +18,29 @@
> >  
> >  #define REG_SET		0x4
> >  #define REG_CLR		0x8
> > +#define ANA_MISC0	0x150
> >  #define ANA_REG_CORE	0x140
> > +#define ANA_REG_2P5	0x130
> 
> Please put these registers in acceding offset.
Accepted.
> 
> >  
> > +#define BM_ANADIG_REG_2P5_ENABLE_WEAK_LINREG	0x40000
> > +#define BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG	0x1000
> >  #define BM_ANADIG_REG_CORE_FET_ODRIVE		0x20000000
> >  
> >  static struct regmap *anatop;
> >  
> > +void imx_anatop_enable_weak2p5(bool enable)
> 
> static
Accepted.
> 
> > +{
> > +	u32 val;
> > +
> > +	regmap_read(anatop, ANA_MISC0, &val);
> > +
> > +	/* can only be enabled when stop_mode_config is clear. */
> > +	regmap_write(anatop, ANA_REG_2P5 + ((enable &&
> > +		((val & BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG)
> > +		== 0)) ? REG_SET : REG_CLR),
> > +		BM_ANADIG_REG_2P5_ENABLE_WEAK_LINREG);
> 
> It's a little difficult to parse the expression even it's on the same
> line, not mentioning with indentation.  There are so many levels of
> parentheses.
> 
>   ((enable && ((val & BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG) == 0)) ? REG_SET : REG_CLR)
> 
> What about rewriting it as below to make it easy for people to read?
> 
>         reg = ANA_REG_2P5;
>         reg += (enable && (val & BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG) == 0) ?
> 		REG_SET : REG_CLR;
>         regmap_write(anatop, reg, BM_ANADIG_REG_2P5_ENABLE_WEAK_LINREG);
Accepted.
> 
> > +}
> > +
> >  void imx_anatop_enable_fet_odrive(bool enable)
> >  {
> >  	regmap_write(anatop, ANA_REG_CORE + (enable ?
> > @@ -32,12 +49,14 @@ void imx_anatop_enable_fet_odrive(bool enable)
> >  
> >  void imx_anatop_pre_suspend(void)
> >  {
> > +	imx_anatop_enable_weak2p5(true);
> >  	imx_anatop_enable_fet_odrive(true);
> >  }
> >  
> >  void imx_anatop_post_resume(void)
> >  {
> >  	imx_anatop_enable_fet_odrive(false);
> > +	imx_anatop_enable_weak2p5(false);
> >  }
> >  
> >  void __init imx_anatop_init(void)
> > diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
> > index b365efc..646ce12 100644
> > --- a/arch/arm/mach-imx/clk-imx6q.c
> > +++ b/arch/arm/mach-imx/clk-imx6q.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/types.h>
> >  #include <linux/clk.h>
> >  #include <linux/clkdev.h>
> > +#include <linux/delay.h>
> >  #include <linux/err.h>
> >  #include <linux/io.h>
> >  #include <linux/of.h>
> > @@ -25,6 +26,8 @@
> >  
> >  #define CCR				0x0
> >  #define BM_CCR_WB_COUNT			(0x7 << 16)
> > +#define BM_CCR_RBC_BYPASS_COUNT		(0x3f << 21)
> > +#define BM_CCR_RBC_EN			(0x1 << 27)
> >  
> >  #define CCGR0				0x68
> >  #define CCGR1				0x6c
> > @@ -70,6 +73,38 @@ void imx6q_set_chicken_bit(void)
> >  	writel_relaxed(val, ccm_base + CGPR);
> >  }
> >  
> > +void imx6q_set_rbc(bool enable)
> 
> Same question as imx6q_set_wb, can we manage to call it in
> imx6q_set_lpm()?  The intension behind this is we should try to
> a centralized place to configure CCM registers/bits for suspend
> instead of exporting so many functions to suspend routine to call
> individually.
Will do it in the way as well bias did.
> 
> > +{
> > +	u32 val;
> > +
> > +	/*
> > +	 * need to mask all interrupts in GPC before
> > +	 * operating RBC configurations
> > +	 */
> > +	imx_gpc_mask_all();
> > +
> > +	/* configurate RBC enable bit */
> 
> s/configurate/configure
Accepted.
> 
> > +	val = readl_relaxed(ccm_base + CCR);
> > +	val &= ~BM_CCR_RBC_EN;
> > +	val |= enable ? BM_CCR_RBC_EN : 0;
> > +	writel_relaxed(val, ccm_base + CCR);
> > +
> > +	/* configurate RBC count */
> 
> Ditto
Accepted.
> 
> > +	val = readl_relaxed(ccm_base + CCR);
> > +	val &= ~BM_CCR_RBC_BYPASS_COUNT;
> > +	val |= enable ? BM_CCR_RBC_BYPASS_COUNT : 0;
> > +	writel(val, ccm_base + CCR);
> > +
> > +	/*
> > +	 * need to delay at least 2 cycles of CKIL(32K)
> > +	 * due to hardware design requirement, which is
> > +	 * ~61us, here we use 65us for safe
> > +	 */
> > +	udelay(65);
> 
> Nit, have a new line here.
Accepted.
> 
> > +	/* restore GPC interrupt mask settings */
> > +	imx_gpc_restore_all();
> > +}
> > +
> >  void imx6q_set_wb(bool enable)
> >  {
> >  	u32 val;
> > diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
> > index b9125cf..66fe41c 100644
> > --- a/arch/arm/mach-imx/common.h
> > +++ b/arch/arm/mach-imx/common.h
> > @@ -129,11 +129,14 @@ extern void imx_src_prepare_restart(void);
> >  extern void imx_gpc_init(void);
> >  extern void imx_gpc_pre_suspend(void);
> >  extern void imx_gpc_post_resume(void);
> > +extern void imx_gpc_mask_all(void);
> > +extern void imx_gpc_restore_all(void);
> >  extern void imx_anatop_init(void);
> >  extern void imx_anatop_pre_suspend(void);
> >  extern void imx_anatop_post_resume(void);
> >  extern int imx6q_set_lpm(enum mxc_cpu_pwr_mode mode);
> >  extern void imx6q_set_chicken_bit(void);
> > +extern void imx6q_set_rbc(bool enable);
> >  extern void imx6q_set_wb(bool enable);
> 
> Since they are taking "enable" parameter, can we rename them as below?
> 
>  void imx6q_enable_rbc(bool enable);
>  void imx6q_enable_wb(bool enable);
OK.
> 
> >  extern void imx_cpu_die(unsigned int cpu);
> >  extern int imx_cpu_kill(unsigned int cpu);
> > diff --git a/arch/arm/mach-imx/gpc.c b/arch/arm/mach-imx/gpc.c
> > index a96ccc7..504049e 100644
> > --- a/arch/arm/mach-imx/gpc.c
> > +++ b/arch/arm/mach-imx/gpc.c
> > @@ -1,5 +1,5 @@
> >  /*
> > - * Copyright 2011 Freescale Semiconductor, Inc.
> > + * Copyright 2011-2013 Freescale Semiconductor, Inc.
> >   * Copyright 2011 Linaro Ltd.
> >   *
> >   * The code contained herein is licensed under the GNU General Public
> > @@ -68,6 +68,25 @@ static int imx_gpc_irq_set_wake(struct irq_data *d, unsigned int on)
> >  	return 0;
> >  }
> >  
> > +void imx_gpc_mask_all(void)
> > +{
> > +	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
> > +	int i;
> > +
> > +	for (i = 0; i < IMR_NUM; i++)
> > +		writel_relaxed(0xffffffff, reg_imr1 + i * 4);
> > +
> > +}
> > +
> > +void imx_gpc_restore_all(void)
> > +{
> > +	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
> > +	int i;
> > +
> > +	for (i = 0; i < IMR_NUM; i++)
> > +		writel_relaxed(gpc_saved_imrs[i], reg_imr1 + i * 4);
> > +}
> > +
> >  static void imx_gpc_irq_unmask(struct irq_data *d)
> >  {
> >  	void __iomem *reg;
> > diff --git a/arch/arm/mach-imx/pm-imx6q.c b/arch/arm/mach-imx/pm-imx6q.c
> > index 57ca274..24ac7bc 100644
> > --- a/arch/arm/mach-imx/pm-imx6q.c
> > +++ b/arch/arm/mach-imx/pm-imx6q.c
> > @@ -36,10 +36,12 @@ static int imx6q_pm_enter(suspend_state_t state)
> >  		imx_gpc_pre_suspend();
> 
> This call saves mask in gpc_saved_imrs and mask all interrupts except
> those wakeup sources ...
> 
> >  		imx_anatop_pre_suspend();
> >  		imx_set_cpu_jump(0, v7_cpu_resume);
> > +		imx6q_set_rbc(true);
> 
> At the end of imx6q_set_rbc(), imx_gpc_restore_all() will be called to
> restore mask bits with gpc_saved_imrs, so wakeup source handling gets
> lost, and any in-use interrupt will wake up system, which is
> undesirable.
Oh, my mistake, will fix it in V2.
> 
> Shawn
> 
> >  		imx6q_set_wb(true);
> >  		/* Zzz ... */
> >  		cpu_suspend(0, imx6q_suspend_finish);
> >  		imx6q_set_wb(false);
> > +		imx6q_set_rbc(false);
> >  		imx_smp_prepare();
> >  		imx_anatop_post_resume();
> >  		imx_gpc_post_resume();
> > -- 
> > 1.7.9.5
> > 
> >