[PATCH 13/23] AT91 DMA OF support
Nicolas Ferre
nicolas.ferre at atmel.com
Tue Aug 14 10:47:05 EDT 2012
Hi Richard,
I am not sure that this one will go further: there is an initiative to
build a pretty generic DMA OF support... It takes time but it is
progressing...
Anyway, there may have some bits to integrate in at_hdmac.c driver: I
will have a closer look later.
Thanks,
On 08/14/2012 03:49 PM, Richard Genoud :
> Signed-off-by: Richard Genoud <richard.genoud at gmail.com>
> ---
> arch/arm/mach-at91/include/mach/at_hdmac.h | 1 +
> drivers/of/Kconfig | 4 +
> drivers/of/Makefile | 1 +
> drivers/of/of_atmel.c | 112 ++++++++++++++++++++++++++++
> include/linux/of_atmel.h | 29 +++++++
> 5 files changed, 147 insertions(+), 0 deletions(-)
> create mode 100644 drivers/of/of_atmel.c
> create mode 100644 include/linux/of_atmel.h
>
> diff --git a/arch/arm/mach-at91/include/mach/at_hdmac.h b/arch/arm/mach-at91/include/mach/at_hdmac.h
> index cab0997..35667bd 100644
> --- a/arch/arm/mach-at91/include/mach/at_hdmac.h
> +++ b/arch/arm/mach-at91/include/mach/at_hdmac.h
> @@ -52,6 +52,7 @@ struct at_dma_slave {
> #define ATC_LOCK_IF_L_CHUNK (0x0 << 22)
> #define ATC_LOCK_IF_L_BUFFER (0x1 << 22)
> #define ATC_AHB_PROT_MASK (0x7 << 24) /* AHB Protection */
> +#define ATC_AHB_PROT(h) (((h) << 24) && ATC_AHB_PROT_MASK)
> #define ATC_FIFOCFG_MASK (0x3 << 28) /* FIFO Request Configuration */
> #define ATC_FIFOCFG_LARGESTBURST (0x0 << 28)
> #define ATC_FIFOCFG_HALFFIFO (0x1 << 28)
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index dfba3e6..4667960 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -83,4 +83,8 @@ config OF_MTD
> depends on MTD
> def_bool y
>
> +config OF_ATMEL
> + depends on AT_HDMAC
> + def_bool y
> +
> endmenu # OF
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index e027f44..897de3b 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -11,3 +11,4 @@ obj-$(CONFIG_OF_MDIO) += of_mdio.o
> obj-$(CONFIG_OF_PCI) += of_pci.o
> obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o
> obj-$(CONFIG_OF_MTD) += of_mtd.o
> +obj-$(CONFIG_OF_ATMEL) += of_atmel.o
> diff --git a/drivers/of/of_atmel.c b/drivers/of/of_atmel.c
> new file mode 100644
> index 0000000..bcd3c54a
> --- /dev/null
> +++ b/drivers/of/of_atmel.c
> @@ -0,0 +1,112 @@
> +/*
> + * Copyright (C) 2012 Richard Genoud, Paratronic S.A.
> + * <richard.genoud at gmail.com>
> + *
> + * Atmel specifics OF helpers
> + *
> + * 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.
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/export.h>
> +#include <linux/device.h>
> +#include <linux/slab.h>
> +#include <linux/printk.h>
> +#include <linux/byteorder/generic.h>
> +#include <mach/at_hdmac.h>
> +#include <linux/of.h>
> +
> +static int of_dev_node_match(struct device *dev, void *data)
> +{
> + return dev->of_node == data;
> +}
> +
> +/**
> + * of_create_at_dma_slave - Alloc and initialize the struct at_dma_slave
> + * @np: pointer to node to create the struct for
> + * @bus: pointer to the bus type of the DMA device.
> + *
> + * Returns pointer to created DMA slave structure, or NULL in case of error.
> + */
> +struct at_dma_slave *of_create_at_dma_slave(struct device_node *np,
> + struct bus_type *bus)
> +{
> + struct at_dma_slave *atslave;
> + struct device_node *n;
> + struct property *prop;
> + const __be32 *dma_list;
> + phandle phandle;
> + int size;
> + int err = -1;
> + u32 val;
> +
> + atslave = kzalloc(sizeof(struct at_dma_slave), GFP_KERNEL);
> + if (unlikely(!atslave)) {
> + pr_err("cannot allocate memory\n");
> + goto error;
> + }
> +
> + atslave->cfg |= of_property_read_bool(np, "atc_src_rep") ? ATC_SRC_REP : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_dst_rep") ? ATC_DST_REP : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_src_h2sel_hw") ? ATC_SRC_H2SEL_HW : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_dst_h2sel_hw") ? ATC_DST_H2SEL_HW : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_sod") ? ATC_SOD : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_lock_if") ? ATC_LOCK_IF : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_lock_b") ? ATC_LOCK_B : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_lock_if_l") ? ATC_LOCK_IF_L : 0;
> + atslave->cfg |= of_property_read_bool(np, "atc_lock_if_l_buffer") ? ATC_LOCK_IF_L_BUFFER : 0;
> + if (of_property_read_bool(np, "atc_fifocfg_halffifo"))
> + atslave->cfg = (atslave->cfg & ~ATC_FIFOCFG_MASK) | ATC_FIFOCFG_HALFFIFO;
> + if (of_property_read_bool(np, "atc_fifocfg_enoughspace"))
> + atslave->cfg = (atslave->cfg & ~ATC_FIFOCFG_MASK) | ATC_FIFOCFG_ENOUGHSPACE;
> + if (of_property_read_bool(np, "atc_fifocfg_largestburst"))
> + atslave->cfg = (atslave->cfg & ~ATC_FIFOCFG_MASK) | ATC_FIFOCFG_LARGESTBURST;
> + if (!of_property_read_u32(np, "atc_ahb_prot", &val))
> + atslave->cfg |= ATC_AHB_PROT(val);
> + if (!of_property_read_u32(np, "atc_src_per", &val))
> + atslave->cfg |= ATC_SRC_PER(val);
> + if (!of_property_read_u32(np, "atc_dst_per", &val))
> + atslave->cfg |= ATC_DST_PER(val);
> +
> + /* we need to associate the wanted dma struct device to
> + * atslave->dma_dev. This is needed when searching for
> + * a free dma channel
> + */
> + prop = of_find_property(np, "dma", &size);
> + if (!prop) {
> + pr_err("can't find the dma child node\n");
> + goto error;
> + }
> + dma_list = prop->value;
> + size /= sizeof(*dma_list);
> + if (size != 1) {
> + pr_err("only one dma handle is supported\n");
> + goto error;
> + }
> +
> + phandle = be32_to_cpup(dma_list);
> + n = of_find_node_by_phandle(phandle);
> + if (!n) {
> + pr_err("unable to find dma device: invalid phandle %s\n",
> + prop->name);
> + goto error;
> + }
> +
> + atslave->dma_dev = bus_find_device(bus, NULL, n, of_dev_node_match);
> + if (!atslave->dma_dev) {
> + pr_err("can't find struct device for DMA %s\n", prop->name);
> + goto error;
> + }
> +
> + pr_debug("DMA cfg register=0x%x DMA device path=%s\n",
> + atslave->cfg, prop->name);
> + err = 0;
> +error:
> + if (err)
> + kfree(atslave);
> + return atslave;
> +}
> +EXPORT_SYMBOL_GPL(of_create_at_dma_slave);
> +
> diff --git a/include/linux/of_atmel.h b/include/linux/of_atmel.h
> new file mode 100644
> index 0000000..256f336
> --- /dev/null
> +++ b/include/linux/of_atmel.h
> @@ -0,0 +1,29 @@
> +#ifndef _LINUX_OF_ATMEL_H
> +#define _LINUX_OF_ATMEL_H
> +/*
> + * Copyright (C) 2012 Richard Genoud, Paratronic S.A.
> + * <richard.genoud at gmail.com>
> + *
> + * Atmel specifics OF helpers
> + *
> + * 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.
> + *
> + */
> +#include <linux/of.h>
> +#include <linux/device.h>
> +#include <mach/at_hdmac.h>
> +
> +#ifdef CONFIG_OF_ATMEL
> +extern struct at_dma_slave *of_create_at_dma_slave(struct device_node *np,
> + struct bus_type *bus);
> +#else
> +static struct at_dma_slave *of_create_at_dma_slave(struct device_node *np,
> + struct bus_type *bus)
> +{
> + return NULL;
> +}
> +#endif /* CONFIG_OF_ATMEL */
> +
> +#endif /* _LINUX_OF_ATMEL_H */
>
--
Nicolas Ferre
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