Re: [PATCH V6 3/3] soc/tegra: pmc: Add support for IO pads power state and voltage

From: Jon Hunter
Date: Fri May 20 2016 - 09:32:50 EST

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On 20/05/16 12:59, Laxman Dewangan wrote:
> The IO pins of Tegra SoCs are grouped for common control of IO
> interface like setting voltage signal levels and power state of
> the interface. The group is generally referred as IO pads. The
> power state and voltage control of IO pins can be done at IO pads
> level.
>
> Tegra generation SoC supports the power down of IO pads when it
> is not used even in the active state of system. This saves power
> from that IO interface. Also it supports multiple voltage level
> in IO pins for interfacing on some of pads. The IO pad voltage is
> automatically detected till T124, hence SW need not to configure
> this. But from T210, the automatically detection logic has been
> removed, hence SW need to explicitly set the IO pad voltage into
> IO pad configuration registers.
>
> Add support to set the power states and voltage level of the IO pads
> from client driver. The implementation for the APIs are in generic
> which is applicable for all generation os Tegra SoC.
>
> IO pads ID and information of bit field for power state and voltage
> level controls are added for Tegra124, Tegra132 and Tegra210. The SOR
> driver is modified to use the new APIs.
>
> Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
>
> ---
> Changes from V1:
> This is reworked on earlier path to have separation between IO rails and
> io pads and add power state and voltage control APIs in single call.
>
> Changes from V2:
> - Remove the tegra_io_rail_power_off/on() apis and change client (sor) driver
> to use the new APIs for IO pad power.
> - Remove the TEGRA_IO_RAIL_ macros.
>
> Changes from V3:
> - Make all pad_id/io_pad_id to id.
> - tegra_io_pad_ -> tegra_io_pads
> - dpd_bit -> bit, pwr_mask/bit to mask/bit.
> - Rename function to tegra_io_pads_{set,get}_voltage_config
> - Make the io pad tables common for all SoC.
> - Make io_pads enums.
> - Add enums for voltage.
>
> Changes from V4:
> - IO_PAD->IO_PADS
> - TEGRA_IO_PADS_POWER_SOURCE_ -> TEGRA_IO_PADS_VCONF_
>
> Changes from V5:
> - Fix comment style to multi-line format.
> - Use -EINVAL instead of -1 to refactor some of function as suggested by Jon.
> ---
> drivers/gpu/drm/tegra/sor.c | 8 +-
> drivers/soc/tegra/pmc.c | 221 ++++++++++++++++++++++++++++++++++++++------
> include/soc/tegra/pmc.h | 133 ++++++++++++++++++--------
> 3 files changed, 295 insertions(+), 67 deletions(-)

...

> +/* tegra_io_pads_config_info: Tegra IO pads bit config info.
> + * @dpd_config_bit: DPD configuration bit position. -1 if not supported.
> + * @voltage_config_bit: Voltage configuration bit position. -1 if not supported.
> + * @soc_mask: Bitwise OR of SoC masks if IO pads supported on that SoC.
> + */

Comment coding style :-(

> +struct tegra_io_pads_config_info {
> + int dpd_config_bit;
> + int voltage_config_bit;
> + int soc_mask;
> +};
> +
> struct tegra_pmc_soc {
> unsigned int num_powergates;
> const char *const *powergates;
> unsigned int num_cpu_powergates;
> const u8 *cpu_powergates;
> -
> + int io_pads_soc_mask;
> bool has_tsense_reset;
> bool has_gpu_clamps;
> };
> @@ -196,6 +220,14 @@ static void tegra_pmc_writel(u32 value, unsigned long offset)
> writel(value, pmc->base + offset);
> }
>
> +static void tegra_pmc_rmw(unsigned long offset, u32 mask, u32 val)
> +{
> + u32 pmc_reg = tegra_pmc_readl(offset);
> +
> + pmc_reg = (pmc_reg & ~mask) | (val & mask);
> + tegra_pmc_writel(pmc_reg, offset);
> +}
> +
> static inline bool tegra_powergate_state(int id)
> {
> if (id == TEGRA_POWERGATE_3D && pmc->soc->has_gpu_clamps)
> @@ -841,21 +873,98 @@ static void tegra_powergate_init(struct tegra_pmc *pmc)
> of_node_put(np);
> }
>
> -static int tegra_io_rail_prepare(unsigned int id, unsigned long *request,
> - unsigned long *status, unsigned int *bit)
> +#define TEGRA_IO_PADS_CONFIG(_id, _dpd, _volt, _soc) \
> +[TEGRA_IO_PADS_##_id] = { \
> + .dpd_config_bit = (_dpd), \
> + .voltage_config_bit = (_volt), \
> + .soc_mask = (_soc), \
> +}
> +
> +static struct tegra_io_pads_config_info
> +tegra_io_pads_configs[TEGRA_IO_PADS_MAX] = {
> + TEGRA_IO_PADS_CONFIG(CSIA, 0, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(CSIB, 1, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(DSI, 2, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(MIPI_BIAS, 3, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(PEX_BIAS, 4, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(PEX_CLK1, 5, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(PEX_CLK2, 6, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(USB0, 9, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(USB1, 10, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(USB2, 11, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(USB_BIAS, 12, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(NAND, 13, -EINVAL, TEGRA_IO_PADS_T124),
> + TEGRA_IO_PADS_CONFIG(UART, 14, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(BB, 15, -EINVAL, TEGRA_IO_PADS_T124),
> + TEGRA_IO_PADS_CONFIG(AUDIO, 17, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(USB3, 18, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(HSIC, 19, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(COMP, 22, -EINVAL, TEGRA_IO_PADS_T124),
> + TEGRA_IO_PADS_CONFIG(DBG, 25, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(DEBUG_NONAO, 26, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(GPIO, 27, 21, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(HDMI, 28, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(PEX_CNTRL, 32, -EINVAL, TEGRA_IO_PADS_T124),
> + TEGRA_IO_PADS_CONFIG(SDMMC1, 33, 12, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(SDMMC3, 34, 13, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(SDMMC4, 35, -EINVAL, TEGRA_IO_PADS_T124),
> + TEGRA_IO_PADS_CONFIG(EMMC, 35, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(CAM, 36, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(EMMC2, 37, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(HV, 38, -EINVAL, TEGRA_IO_PADS_T124),
> + TEGRA_IO_PADS_CONFIG(DSIB, 39, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(DSIC, 40, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(DSID, 41, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(CSIC, 42, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(CSID, 43, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(CSIE, 44, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(CSIF, 45, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(SPI, 46, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(SPI_HV, 47, 23, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(DMIC, 50, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(DP, 51, -EINVAL, TEGRA_IO_PADS_T210),
> + TEGRA_IO_PADS_CONFIG(LVDS, 57, -EINVAL, TEGRA_IO_PADS_T124_T210),
> + TEGRA_IO_PADS_CONFIG(SYS_DDC, 58, -EINVAL, TEGRA_IO_PADS_T124),
> + TEGRA_IO_PADS_CONFIG(AUDIO_HV, 61, 18, TEGRA_IO_PADS_T210),
> +};
> +
> +static inline int tegra_io_pads_to_dpd_bit(const struct tegra_pmc_soc *soc,
> + enum tegra_io_pads id)
> {
> - unsigned long rate, value;
> + if (tegra_io_pads_configs[id].soc_mask & soc->io_pads_soc_mask)
> + return tegra_io_pads_configs[id].dpd_config_bit;

I realise now that we are not checking if 'id' is greater than
TEGRA_IO_PADS_MAX anywhere. This should probably be handled here.
>
> - *bit = id % 32;
> + return -EINVAL;
> +}
>
> - /*
> - * There are two sets of 30 bits to select IO rails, but bits 30 and
> - * 31 are control bits rather than IO rail selection bits.
> - */
> - if (id > 63 || *bit == 30 || *bit == 31)
> +static int tegra_io_pads_to_voltage_bit(const struct tegra_pmc_soc *soc,
> + enum tegra_io_pads id)
> +{
> + /* T210 only supports io-pad voltage config bit */
> + if (soc->io_pads_soc_mask != TEGRA_IO_PADS_T210)
> return -EINVAL;
>
> - if (id < 32) {
> + if (tegra_io_pads_configs[id].soc_mask & soc->io_pads_soc_mask)
> + return tegra_io_pads_configs[id].voltage_config_bit;

Same here for 'id'

> +
> + return -EINVAL;
> +}
> +
> +static int tegra_io_pads_dpd_prepare(enum tegra_io_pads id,
> + unsigned long *request,
> + unsigned long *status,
> + unsigned int *bit)
> +{
> + unsigned long rate, value;
> + int ret;
> +
> + ret = tegra_io_pads_to_dpd_bit(pmc->soc, id);
> + if (ret < 0)
> + return ret;
> +
> + *bit = ret % 32;
> +
> + if (*bit < 32) {

Isn't bit always less than 32 here now?

Cheers
Jon

--
nvpublic

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In reply to: Laxman Dewangan: "[PATCH V6 3/3] soc/tegra: pmc: Add support for IO pads power state and voltage"
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