Re: [RFC 5/8] remoteproc: add davinci implementation

[Sergei Shtylyov <sshtylyov@mvista.com>]

Hello.

Ohad Ben-Cohen wrote:

> From: Mark Grosen <mgrosen@ti.com>

> Add remoteproc implementation for da850, so we can boot its DSP.

> Signed-off-by: Mark Grosen <mgrosen@ti.com>
> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
> ---
>  arch/arm/mach-davinci/include/mach/remoteproc.h |   28 +++++
>  drivers/remoteproc/Kconfig                      |   16 +++
>  drivers/remoteproc/Makefile                     |    1 +
>  drivers/remoteproc/davinci_remoteproc.c         |  147 +++++++++++++++++++++++
>  4 files changed, 192 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/mach-davinci/include/mach/remoteproc.h
>  create mode 100644 drivers/remoteproc/davinci_remoteproc.c

> diff --git a/arch/arm/mach-davinci/include/mach/remoteproc.h b/arch/arm/mach-davinci/include/mach/remoteproc.h
> new file mode 100644
> index 0000000..af6e88c
> --- /dev/null
> +++ b/arch/arm/mach-davinci/include/mach/remoteproc.h
> @@ -0,0 +1,28 @@
> +/*
> + * Remote Processor
> + *
> + * Copyright (C) 2011 Texas Instruments, Inc.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _DAVINCI_REMOTEPROC_H
> +#define _DAVINCI_REMOTEPROC_H
> +
> +#include <linux/remoteproc.h>
> +
> +struct davinci_rproc_pdata {
> +	struct rproc_ops *ops;
> +	char *name;
> +	char *clk_name;
> +	char *firmware;
> +};
> +
> +#endif /* _DAVINCI_REMOTEPROC_H */
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index 88421bd..1e594b5 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -26,3 +26,19 @@ config OMAP_REMOTE_PROC
>  
>  	  It's safe to say n here if you're not interested in multimedia
>  	  offloading or just want a bare minimum kernel.
> +
> +config DAVINCI_REMOTE_PROC
> +	tristate "Davinci remoteproc support"
> +	depends on ARCH_DAVINCI_DA850

    It should work on DA830 as well, but not on real DaVinci, so the name is 
misleading...

[...]
> diff --git a/drivers/remoteproc/davinci_remoteproc.c b/drivers/remoteproc/davinci_remoteproc.c
> new file mode 100644
> index 0000000..0e26fe9
> --- /dev/null
> +++ b/drivers/remoteproc/davinci_remoteproc.c
> @@ -0,0 +1,147 @@
> +/*
> + * Remote processor machine-specific module for Davinci
> + *
> + * Copyright (C) 2011 Texas Instruments, Inc.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#define pr_fmt(fmt)    "%s: " fmt, __func__
> +
> +#include <linux/kernel.h>
> +#include <linux/err.h>
> +#include <linux/printk.h>
> +#include <linux/bitops.h>
> +#include <linux/platform_device.h>
> +#include <linux/remoteproc.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +
> +#include <mach/da8xx.h>
> +#include <mach/cputype.h>
> +#include <mach/psc.h>
> +#include <mach/remoteproc.h>
> +
> +/*
> + * Technical Reference:
> + * OMAP-L138 Applications Processor System Reference Guide
> + * http://www.ti.com/litv/pdf/sprugm7d
> + */
> +
> +/* local reset bit (0 is asserted) in MDCTL15 register (section 9.6.18) */
> +#define LRST		BIT(8)

    Perhaps this should be named nLRST or something if the sense is inverted?

> +/* next state bits in MDCTL15 register (section 9.6.18) */
> +#define NEXT_ENABLED	0x3

    Isn't this already declared in <mach/psc.h> as PSC_STATE_ENABLED?

> +/* register for DSP boot address in SYSCFG0 module (section 11.5.6) */
> +#define HOST1CFG	0x44

    Worth declaring in <mach/da8xx.h> instead...

> +static inline int davinci_rproc_start(struct rproc *rproc, u64 bootaddr)
> +{
> +	struct device *dev = rproc->dev;
> +	struct davinci_rproc_pdata *pdata = dev->platform_data;
> +	struct davinci_soc_info *soc_info = &davinci_soc_info;
> +	void __iomem *psc_base;
> +	struct clk *dsp_clk;
> +
> +	/* hw requires the start (boot) address be on 1KB boundary */
> +	if (bootaddr & 0x3ff) {
> +		dev_err(dev, "invalid boot address: must be aligned to 1KB\n");
> +		return -EINVAL;
> +	}
> +
> +	dsp_clk = clk_get(dev, pdata->clk_name);

    We could match using clkdev functionality, but the clock entry would need to 
be changed then...

> +	if (IS_ERR_OR_NULL(dsp_clk)) {
> +		dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
> +		return PTR_ERR(dsp_clk);
> +	}
> +
> +	clk_enable(dsp_clk);

     This seems rather senseless activity as on DA8xx the DSP core boots the ARM 
core, so the DSP clock will be already enabled.

> +	rproc->priv = dsp_clk;
> +
> +	psc_base = ioremap(soc_info->psc_bases[0], SZ_4K);
> +
> +	/* insure local reset is asserted before writing start address */
> +	__raw_writel(NEXT_ENABLED, psc_base + MDCTL + 4 * DA8XX_LPSC0_GEM);
> +
> +	__raw_writel(bootaddr, DA8XX_SYSCFG0_VIRT(HOST1CFG));

    DA8XX_SYSCFG0_VIRT() is not supposed to be used outside mach-davinci. The 
variable it refers is not exported, so driver module won't work.

> +	/* de-assert local reset to start the dsp running */
> +	__raw_writel(LRST | NEXT_ENABLED, psc_base + MDCTL +
> +		4 * DA8XX_LPSC0_GEM);
> +
> +	iounmap(psc_base);
> +
> +	return 0;
> +}
> +
> +static inline int davinci_rproc_stop(struct rproc *rproc)
> +{
> +	struct davinci_soc_info *soc_info = &davinci_soc_info;
> +	void __iomem *psc_base;
> +	struct clk *dsp_clk = rproc->priv;
> +
> +	psc_base = ioremap(soc_info->psc_bases[0], SZ_4K);
> +
> +	/* halt the dsp by asserting local reset */
> +	__raw_writel(NEXT_ENABLED, psc_base + MDCTL + 4 * DA8XX_LPSC0_GEM);
> +
> +	clk_disable(dsp_clk);
> +	clk_put(dsp_clk);
> +
> +	iounmap(psc_base);
> +
> +	return 0;
> +}

    All this is DA8xx specific code which won't fly on real DaVincis, so I 
suggest that you rename the file to da8xx_remoteproc.c for clarity; and rename 
the patch as well...

WBR, Sergei