Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1378112

Re: [PATCH 2/5] regulator: st-flashss: Add a regulator driver for flashss vsense.

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

On Wed, Apr 13, 2016 at 09:59:00AM +0200, Giuseppe CAVALLARO wrote:
> On 4/13/2016 8:15 AM, Mark Brown wrote:
> >>>+static void st_get_satinize_powerup_voltage(struct st_vsense *vsense)
> >>>+{

> >or am I missing something?  Why do we need to do this anyway, it's very
> >surprsing?

> This functions is to sanitize the vsense voltages when the regulator
> is probed and in some circumstances the reset value of this register
> does not reflect the hw status/config. For example, by default, after
> the reset, the bit 0 is set so the EMMC, inside the flash subsystem,
> is supposed to operate at 3v3. But the latched bit 24 can be 0 on
> a platform where it is actually set at 1v8.
> So the bit 0 must be reset to keep this coherent and to allow MMC
> framework to properly setup the Vdd when the framework starts.

I'm afraid I can't follow that explanation, perhaps because I don't know
anything about the content of this register except for these three bits.
I think we do need a comment in the driver explaining what's going on,
and probably a simplification of the code too if my understanding of the
effect of all those operations is correct.

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 0/5] Add st-flashss vsense regulator driver Peter Griffin <peter.griffin@linaro.org> - 2016-04-12 17:30 +0200
  [PATCH 1/5] regulator: st-flashss: Add DT binding documentation for flashss regulator. Peter Griffin <peter.griffin@linaro.org> - 2016-04-12 17:30 +0200
  [PATCH 2/5] regulator: st-flashss: Add a regulator driver for flashss vsense. Peter Griffin <peter.griffin@linaro.org> - 2016-04-12 17:30 +0200
    Re: [PATCH 2/5] regulator: st-flashss: Add a regulator driver for  flashss vsense. Mark Brown <broonie@kernel.org> - 2016-04-13 08:20 +0200
      Re: [PATCH 2/5] regulator: st-flashss: Add a regulator driver for  flashss vsense. Giuseppe CAVALLARO <peppe.cavallaro@st.com> - 2016-04-13 10:00 +0200
        Re: [PATCH 2/5] regulator: st-flashss: Add a regulator driver for  flashss vsense. Mark Brown <broonie@kernel.org> - 2016-04-13 19:30 +0200
          Re: [PATCH 2/5] regulator: st-flashss: Add a regulator driver for  flashss vsense. Giuseppe CAVALLARO <peppe.cavallaro@st.com> - 2016-04-14 16:20 +0200
            Re: [PATCH 2/5] regulator: st-flashss: Add a regulator driver for  flashss vsense. Mark Brown <broonie@kernel.org> - 2016-04-14 17:30 +0200
  [PATCH 4/5] ARM: multi_v7_defconfig: Enable flashss regulator driver. Peter Griffin <peter.griffin@linaro.org> - 2016-04-12 17:30 +0200
  [PATCH 5/5] ARM: STi: DT: STiH407: Add the flashss voltage regulator DT node. Peter Griffin <peter.griffin@linaro.org> - 2016-04-12 17:30 +0200

csiph-web