RE: [PATCH v3] tty: samsung_tty: 32-bit access for TX/RX hold registers

From: "Hyunki Koo" <hyunki00.koo@samsung.com>
To: "'Krzysztof Kozlowski'" <krzk@kernel.org>
Cc: linux-samsung-soc@vger.kernel.org, gregkh@linuxfoundation.org,
	linux-kernel@vger.kernel.org, 'Kukjin Kim' <kgene@kernel.org>,
	linux-serial@vger.kernel.org, 'Jiri Slaby' <jslaby@suse.com>,
	linux-arm-kernel@lists.infradead.org
Subject: RE: [PATCH v3] tty: samsung_tty: 32-bit access for TX/RX hold registers
Date: Fri, 3 Apr 2020 20:12:55 +0900	[thread overview]
Message-ID: <005601d609a8$d3243710$796ca530$@samsung.com> (raw)
In-Reply-To: <20200403104744.GA29385@kozik-lap>

On Thu, Apr 02, 2020 at 7:48:38PM +0900, Krzysztof Kozlowski
> On Fri, Apr 03, 2020 at 07:20:41PM +0900, Hyunki Koo wrote:
> > Support 32-bit access for the TX/RX hold registers UTXH and URXH.
> >
> > This is required for some newer SoCs.
> >
> > Signed-off-by: Hyunki Koo <hyunki00.koo@samsung.com>
> > ---
> > v3: change rd_regl to rd_reg in line 954 for backward compatibility.
> 
> I cannot find this change against v2.
Okay, I will add all changes.
> 
> > ---
> >
> >  drivers/tty/serial/samsung_tty.c | 76
> > +++++++++++++++++++++++++++++++++-------
> >  1 file changed, 64 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/tty/serial/samsung_tty.c
> > b/drivers/tty/serial/samsung_tty.c
> > index 73f951d65b93..a674a80163ed 100644
> > --- a/drivers/tty/serial/samsung_tty.c
> > +++ b/drivers/tty/serial/samsung_tty.c
> > @@ -154,12 +154,47 @@ struct s3c24xx_uart_port {  #define
> > portaddrl(port, reg) \
> >  	((unsigned long *)(unsigned long)((port)->membase + (reg)))
> >
> > -#define rd_regb(port, reg) (readb_relaxed(portaddr(port, reg)))
> > +static unsigned int rd_reg(struct uart_port *port, int reg)
> 
> You should return here u32 to be consistent with readl_relaxed.
> 
> > +{
> > +	switch (port->iotype) {
> > +	case UPIO_MEM:
> > +		return readb_relaxed(portaddr(port, reg));
> > +	case UPIO_MEM32:
> > +		return readl_relaxed(portaddr(port, reg));
> > +	default:
> > +		return 0;
> > +	}
> > +	return 0;
> > +}
> > +
> >  #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
> >
> > -#define wr_regb(port, reg, val) writeb_relaxed(val, portaddr(port,
> > reg))
> > +static void wr_reg(struct uart_port *port, int reg, int val)
> 
> val should be u32.
Okay, I will apply it.
> 
> > +{
> > +	switch (port->iotype) {
> > +	case UPIO_MEM:
> > +		writeb_relaxed(val, portaddr(port, reg));
> > +		break;
> > +	case UPIO_MEM32:
> > +		writel_relaxed(val, portaddr(port, reg));
> > +		break;
> > +	}
> > +}
> > +
> >  #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port,
> > reg))
> >
> > +static void write_buf(struct uart_port *port, int reg, int val)
> 
> buf is misleading, you do not write here any buffer. Maybe
> "wr_reg_barrier()" or "wr_reg_order()"?
Okay, wr_reg_barrier  would be good, I will apply it.
> 
> Best regards,
> Krzysztof


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