Re: [PATCH V2 2/2] pinctrl: tegra: Add driver to configure voltage and power of io pads
From: Laxman Dewangan <hidden>
Date: 2016-11-21 09:52:48
Also in:
linux-gpio, linux-tegra, lkml
Hi Jon, I will update the patch per your comment. Here is answer for some of the query. Thanks, Laxman On Tuesday 15 November 2016 08:37 PM, Jon Hunter wrote:
On 09/11/16 13:06, Laxman Dewangan wrote:quoted
+/** + * Macro for 1.8V, keep 200mV as tolerance for deciding that + * IO pads should be set for 3.3V (high voltage) or 1.8V. + */ +#define TEGRA_IO_PAD_1800000UV_UPPER_LIMIT 2000000Is there a reference we could add for the source of this information?
I had a discussion with the ASIC on this and as per them
1.8 V nominal is (1.62V, 1.98V)
3.3 V nominal is (2.97V,3.63V)
I am working with them to update the TRM document but we can assume that
this information will be there in TRM.
quoted
+ const struct pinctrl_pin_desc *pins_desc; + int num_pins_desc; +}; + +struct tegra_io_pads_regulator_info { + struct device *dev; + const struct tegra_io_pads_cfg_info *pads_cfg; + struct regulator *regulator; + struct notifier_block regulator_nb; +};Is this struct necessary? Seems to be a lot of duplicated information from the other structs. Why not add the regulator and regulator_nb to the main struct? OK, not all io_pads have a regulator but you are only saving one pointer.
Yes, some of IO pads support multi-voltage.
+ if ((vdata->old_uV > TEGRA_IO_PAD_1800000UV_UPPER_LIMIT) && + (vdata->min_uV <= TEGRA_IO_PAD_1800000UV_UPPER_LIMIT)) + break; The data-sheet for Tegra210 only lists 1.8V or 3.3V as supported options. Do we need to support a range? Or does the h/w support a range of voltages? I am just wondering why we cannot check explicitly for 1.8V or 3.3V and treat anything else as an error.
Two voltage level, not range.