答复: [2/2] mfd: max77620: Add low battery monitor support

[Mark Zhang <markz@nvidia.com>]

Oh I know that issue and it should be fixed by:
https://marc.info/?l=linux-kernel&m=154745840513141&w=3
The root cause is that max77620 doesn't have a dedicated gpio interrupt mask register,
so the "mask_base" of max77620 gpio driver is 0, that's why regmap_add_irq_chip writes 0xFF
to offset zero.

Mark

-----邮件原件-----
发件人: Billy Laws <blaws05@gmail.com> 
发送时间: Tuesday, January 29, 2019 9:34 PM
收件人: Mark Zhang <markz@nvidia.com>
抄送: Lee Jones <lee.jones@linaro.org>; linux-kernel@vger.kernel.org; linux-tegra@vger.kernel.org; Laxman Dewangan <ldewangan@nvidia.com>; Venkat Reddy Talla <vreddytalla@nvidia.com>
主题: Re: [2/2] mfd: max77620: Add low battery monitor support

It does, see this article
https://blog.quendi.moe/2018/07/03/en-debugging-nintendo-switch-linux-power-management-battery-desync-edition/


On Tue, Jan 29, 2019 at 9:03 AM Mark Zhang <markz@nvidia.com> wrote:
>
> On 1/29/2019 3:36 PM, Billy Laws wrote:
> > Sure, that's fine with me, will send then this gets accepted. Two 
> > other things: you should probably set the reg to 0 if the property 
> > isn't specified as regmap_add_irqchip sets it to 0xff (basically all 
> > enabled on highest limit), and you haven't updated the dt-bindings.
>
> Billy, v2 is out, dt-bindings patches are added.
> But after a second thought, I don't think regmap_add_irqchip might set 
> registers to 0xff. I mean, for 2 registers which this patch set 
> touches, they're not IRQ registers(mask/status/...), so 
> regmap_add_irqchip should not touch them so I didn't make changes to driver codes in v2.
>
> Mark
>
> >
> > On Tue, Jan 29, 2019 at 6:52 AM Mark Zhang <markz@nvidia.com> wrote:
> >>
> >> On 1/27/2019 10:54 PM, Billy Laws wrote:
> >>>  >This patch adds PMIC configurations for low-battery  >monitoring 
> >>> by handling max77620 register CNFGGLBL1.
> >>>  >
> >>> It might be an idea to add lbhyst configuration here and support 
> >>> using custom lbdac values to specify a different cutoff point.
> >>
> >> Yeah this patch doesn't have support to program LBHYST & LBDAC 
> >> because according to our experiences, we don't have requirement to 
> >> modify them when low battery monitor support added.
> >>
> >> I think we can create a new patch to support these 2 fields in the 
> >> future when we really need them. Or you can create a patch if you 
> >> have requirement for them, is this OK to you Billy?
> >>
> >> Mark
> >>
> >>>
> >>> See: https://datasheetspdf.com/pdf-file/924230/Maxim/MAX8698C/1  
> >>> pg 46
> >>>  >Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
> >>>  >Signed-off-by: Venkat Reddy Talla <vreddytalla@nvidia.com>
> >>>  >Signed-off-by: Mark Zhang <markz@nvidia.com>
> >>>  >---
> >>>  > drivers/mfd/max77620.c | 57 
> >>> +++++++++++++++++++++++++++++++++++++++++-
> >>>  > 1 file changed, 56 insertions(+), 1 deletion(-)  >  >diff --git 
> >>> a/drivers/mfd/max77620.c b/drivers/mfd/max77620.c  >index 
> >>> f58143103185..9e50d145afd8 100644
> >>>  >--- a/drivers/mfd/max77620.c
> >>>  >+++ b/drivers/mfd/max77620.c
> >>>  >@@ -474,6 +474,57 @@ static int
> >>> max77620_init_backup_battery_charging(struct max77620_chip *chip)  
> >>> >  return ret;  > }  >  >+static int 
> >>> max77620_init_low_battery_monitor(struct max77620_chip *chip)  >+{  
> >>> >+ struct device *dev = chip->dev;  >+ struct device_node *np;  >+ 
> >>> bool pval;  >+ u8 mask = 0;  >+ u8 val = 0;  >+ int ret;  >+  >+ 
> >>> np = of_get_child_by_name(dev->of_node, "low-battery-monitor");  
> >>> >+ if (!np) {  >+ dev_info(dev, "Low battery monitoring support 
> >>> disabled\n");  >+ return 0;  >+ }  >+  >+ pval = 
> >>> of_property_read_bool(np, "maxim,low-battery-dac-enable");  >+ if 
> >>> (pval) {  >+ mask |= MAX77620_CNFGGLBL1_LBDAC_EN;  >+ val |= 
> >>> MAX77620_CNFGGLBL1_LBDAC_EN;  >+ }  >+  >+ pval = 
> >>> of_property_read_bool(np, "maxim,low-battery-dac-disable");  >+ if 
> >>> (pval)  >+ mask |= MAX77620_CNFGGLBL1_LBDAC_EN;  >+  >+ pval = 
> >>> of_property_read_bool(np, "maxim,low-battery-shutdown-enable");
> >>>  >+ if (pval) {
> >>>  >+ mask |= MAX77620_CNFGGLBL1_MPPLD;  >+ val |= 
> >>> MAX77620_CNFGGLBL1_MPPLD;  >+ }  >+  >+ pval = 
> >>> of_property_read_bool(np, "maxim,low-battery-shutdown-disable");
> >>>  >+ if (pval)
> >>>  >+ mask |= MAX77620_CNFGGLBL1_MPPLD;  >+  >+ pval = 
> >>> of_property_read_bool(np, "maxim,low-battery-reset-enable");
> >>>  >+ if (pval) {
> >>>  >+ mask |= MAX77620_CNFGGLBL1_LBRSTEN;  >+ val |= 
> >>> MAX77620_CNFGGLBL1_LBRSTEN;  >+ }  >+  >+ pval = 
> >>> of_property_read_bool(np, "maxim,low-battery-reset-disable");
> >>>  >+ if (pval)
> >>>  >+ mask |= MAX77620_CNFGGLBL1_LBRSTEN;  >+  >+ ret = 
> >>> regmap_update_bits(chip->rmap, MAX77620_REG_CNFGGLBL1, mask, val);  
> >>> >+ if (ret < 0)  >+ dev_err(dev, "Reg CNFGGLBL1 update failed: 
> >>> %d\n", ret);  >+ return ret;  >+}  >+  > static int 
> >>> max77620_read_es_version(struct max77620_chip *chip)  > {  >  
> >>> unsigned int val;  >@@ -563,7 +614,11 @@ static int 
> >>> max77620_probe(struct i2c_client *client,  >  if (ret < 0)  >  
> >>> return ret;  >
> >>>  >- ret =  devm_mfd_add_devices(chip->dev, PLATFORM_DEVID_NONE,  
> >>> >+ ret = max77620_init_low_battery_monitor(chip);
> >>>  >+ if (ret < 0)
> >>>  >+ return ret;
> >>>  >+
> >>>  >+ ret = devm_mfd_add_devices(chip->dev, PLATFORM_DEVID_NONE,
> >>>  >      mfd_cells, n_mfd_cells, NULL, 0,
> >>>  >      regmap_irq_get_domain(chip->top_irq_data));
> >>>  >  if (ret < 0) {
> >>>