Hi Biju,
On Mon, Nov 7, 2022 at 12:39 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > On Mon, Nov 7, 2022 at 11:35 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > > > -----Original Message-----
> > > > From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > > > Sent: 07 November 2022 10:28
> > > > On Fri, Oct 28, 2022 at 12:42 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > wrote:
> > > > > RZ/G2L General PWM Timer (GPT) composed of 8 channels with 32-bit
> > > > > timer (GPT32E). It supports the following functions
> > > > > * 32 bits × 8 channels
> > > > > * Up-counting or down-counting (saw waves) or up/down-counting
> > > > > (triangle waves) for each counter.
> > > > > * Clock sources independently selectable for each channel
> > > > > * Two I/O pins per channel
> > > > > * Two output compare/input capture registers per channel
> > > > > * For the two output compare/input capture registers of each channel,
> > > > > four registers are provided as buffer registers and are capable of
> > > > > operating as comparison registers when buffering is not in use.
> > > > > * In output compare operation, buffer switching can be at crests or
> > > > > troughs, enabling the generation of laterally asymmetric PWM
> > waveforms.
> > > > > * Registers for setting up frame cycles in each channel (with
> > capability
> > > > > for generating interrupts at overflow or underflow)
> > > > > * Generation of dead times in PWM operation
> > > > > * Synchronous starting, stopping and clearing counters for arbitrary
> > > > > channels
> > > > > * Starting, stopping, clearing and up/down counters in response to
> > input
> > > > > level comparison
> > > > > * Starting, clearing, stopping and up/down counters in response to a
> > > > > maximum of four external triggers
> > > > > * Output pin disable function by dead time error and detected
> > > > > short-circuits between output pins
> > > > > * A/D converter start triggers can be generated (GPT32E0 to
> > > > > GPT32E3)
> > > > > * Enables the noise filter for input capture and external trigger
> > > > > operation
> > > > >
> > > > > This patch adds basic pwm support for RZ/G2L GPT driver by
> > > > > creating separate logical channels for each IOs.
> > > > >
> > > > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > > > ---
> > > > > v8->v9:
> > > > > * deassert after devm_clk_get() to avoid reset stays deasserted,in
> > case
> > > > > clk_get() fails.
> > > > > * Removed ch_offs from struct rzg2l_gpt_chip and use macro instead.
> > > > > * Removed clk_disable_unprepare() from probe as it is giving
> > > > > gpt_pclk already disabled warning in the error path.
> > > > > [ 0.915664] clk_core_disable+0x25c/0x274
> > > > > [ 0.915754] clk_disable+0x2c/0x44
> > > > > [ 0.915833] rzg2l_gpt_pm_runtime_suspend+0x1c/0x34
> > > > > [ 0.915938] pm_generic_runtime_suspend+0x28/0x40
> > > > > [ 0.916042] genpd_runtime_suspend+0xa8/0x2b0
> > > > > [ 0.916136] __rpm_callback+0x44/0x13c
> > > > > [ 0.916218] rpm_callback+0x64/0x70
> > > > > [ 0.916296] rpm_suspend+0x104/0x630
> > > > > [ 0.916374] pm_runtime_work+0xb4/0xbc
> > > > > [ 0.916456] process_one_work+0x288/0x6a
> > > >
> > > > Thanks for the update!
> > > >
> > > > > --- /dev/null
> > > > > +++ b/drivers/pwm/pwm-rzg2l-gpt.c
> > > > > + /*
> > > > > + * We need to keep the clock on, in case the bootloader has
> > enabled the
> > > > > + * PWM and is running during probe().
> > > > > + */
> > > > > + for (i = 0; i < RZG2L_MAX_PWM_CHANNELS; i++) {
> > > > > + ch_en[i] = rzg2l_gpt_is_ch_enabled(rzg2l_gpt, i);
> > > > > + if (ch_en[i])
> >
> > ch_en[] could be a bitmask instead of an array...
>
> It is a local array. Maybe we need to initialize a u8
> variable to 0 initially for bitmask operation??
Yes, regardless of using an array or a bitmask, it must be initialized
to (all) zero(es).
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
