drivers: memory: Introduce Marvell EBU Device Bus driver

Marvell EBU SoCs such as Armada 370/XP, Orion5x (88f5xxx) and
Discovery (mv78xx0) supports a Device Bus controller to access several
kinds of memories and I/O devices (NOR, NAND, SRAM, FPGA).

This commit adds a driver to handle this controller. So far only
Armada 370, Armada XP and Discovery SoCs are supported.

The driver must be registered through a device tree node;
as explained in the binding document.

For each child node in the device tree, this driver will:
  * set timing parameters
  * register a child device
  * setup an address decoding window, using the mbus driver

Keep in mind the address decoding window setup is only a temporary hack.
This code will be removed from this devbus driver as soon as a proper device
tree binding for the mbus driver is added.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ezequiel Garcia
2013-04-23 16:21:26 -03:00
committed by Greg Kroah-Hartman
parent ced9017a4f
commit 3edad321b1
4 changed files with 507 additions and 0 deletions
+10
View File
@@ -20,6 +20,16 @@ config TI_EMIF
parameters and other settings during frequency, voltage and
temperature changes
config MVEBU_DEVBUS
bool "Marvell EBU Device Bus Controller"
default y
depends on PLAT_ORION && OF
help
This driver is for the Device Bus controller available in some
Marvell EBU SoCs such as Discovery (mv78xx0), Orion (88f5xxx) and
Armada 370 and Armada XP. This controller allows to handle flash
devices such as NOR, NAND, SRAM, and FPGA.
config TEGRA20_MC
bool "Tegra20 Memory Controller(MC) driver"
default y
+1
View File
@@ -6,5 +6,6 @@ ifeq ($(CONFIG_DDR),y)
obj-$(CONFIG_OF) += of_memory.o
endif
obj-$(CONFIG_TI_EMIF) += emif.o
obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o
obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o
obj-$(CONFIG_TEGRA30_MC) += tegra30-mc.o
+340
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@@ -0,0 +1,340 @@
/*
* Marvell EBU SoC Device Bus Controller
* (memory controller for NOR/NAND/SRAM/FPGA devices)
*
* Copyright (C) 2013 Marvell
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/mbus.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
/* Register definitions */
#define DEV_WIDTH_BIT 30
#define BADR_SKEW_BIT 28
#define RD_HOLD_BIT 23
#define ACC_NEXT_BIT 17
#define RD_SETUP_BIT 12
#define ACC_FIRST_BIT 6
#define SYNC_ENABLE_BIT 24
#define WR_HIGH_BIT 16
#define WR_LOW_BIT 8
#define READ_PARAM_OFFSET 0x0
#define WRITE_PARAM_OFFSET 0x4
static const char * const devbus_wins[] = {
"devbus-boot",
"devbus-cs0",
"devbus-cs1",
"devbus-cs2",
"devbus-cs3",
};
struct devbus_read_params {
u32 bus_width;
u32 badr_skew;
u32 turn_off;
u32 acc_first;
u32 acc_next;
u32 rd_setup;
u32 rd_hold;
};
struct devbus_write_params {
u32 sync_enable;
u32 wr_high;
u32 wr_low;
u32 ale_wr;
};
struct devbus {
struct device *dev;
void __iomem *base;
unsigned long tick_ps;
};
static int get_timing_param_ps(struct devbus *devbus,
struct device_node *node,
const char *name,
u32 *ticks)
{
u32 time_ps;
int err;
err = of_property_read_u32(node, name, &time_ps);
if (err < 0) {
dev_err(devbus->dev, "%s has no '%s' property\n",
name, node->full_name);
return err;
}
*ticks = (time_ps + devbus->tick_ps - 1) / devbus->tick_ps;
dev_dbg(devbus->dev, "%s: %u ps -> 0x%x\n",
name, time_ps, *ticks);
return 0;
}
static int devbus_set_timing_params(struct devbus *devbus,
struct device_node *node)
{
struct devbus_read_params r;
struct devbus_write_params w;
u32 value;
int err;
dev_dbg(devbus->dev, "Setting timing parameter, tick is %lu ps\n",
devbus->tick_ps);
/* Get read timings */
err = of_property_read_u32(node, "devbus,bus-width", &r.bus_width);
if (err < 0) {
dev_err(devbus->dev,
"%s has no 'devbus,bus-width' property\n",
node->full_name);
return err;
}
/* Convert bit width to byte width */
r.bus_width /= 8;
err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps",
&r.badr_skew);
if (err < 0)
return err;
err = get_timing_param_ps(devbus, node, "devbus,turn-off-ps",
&r.turn_off);
if (err < 0)
return err;
err = get_timing_param_ps(devbus, node, "devbus,acc-first-ps",
&r.acc_first);
if (err < 0)
return err;
err = get_timing_param_ps(devbus, node, "devbus,acc-next-ps",
&r.acc_next);
if (err < 0)
return err;
err = get_timing_param_ps(devbus, node, "devbus,rd-setup-ps",
&r.rd_setup);
if (err < 0)
return err;
err = get_timing_param_ps(devbus, node, "devbus,rd-hold-ps",
&r.rd_hold);
if (err < 0)
return err;
/* Get write timings */
err = of_property_read_u32(node, "devbus,sync-enable",
&w.sync_enable);
if (err < 0) {
dev_err(devbus->dev,
"%s has no 'devbus,sync-enable' property\n",
node->full_name);
return err;
}
err = get_timing_param_ps(devbus, node, "devbus,ale-wr-ps",
&w.ale_wr);
if (err < 0)
return err;
err = get_timing_param_ps(devbus, node, "devbus,wr-low-ps",
&w.wr_low);
if (err < 0)
return err;
err = get_timing_param_ps(devbus, node, "devbus,wr-high-ps",
&w.wr_high);
if (err < 0)
return err;
/* Set read timings */
value = r.bus_width << DEV_WIDTH_BIT |
r.badr_skew << BADR_SKEW_BIT |
r.rd_hold << RD_HOLD_BIT |
r.acc_next << ACC_NEXT_BIT |
r.rd_setup << RD_SETUP_BIT |
r.acc_first << ACC_FIRST_BIT |
r.turn_off;
dev_dbg(devbus->dev, "read parameters register 0x%p = 0x%x\n",
devbus->base + READ_PARAM_OFFSET,
value);
writel(value, devbus->base + READ_PARAM_OFFSET);
/* Set write timings */
value = w.sync_enable << SYNC_ENABLE_BIT |
w.wr_low << WR_LOW_BIT |
w.wr_high << WR_HIGH_BIT |
w.ale_wr;
dev_dbg(devbus->dev, "write parameters register: 0x%p = 0x%x\n",
devbus->base + WRITE_PARAM_OFFSET,
value);
writel(value, devbus->base + WRITE_PARAM_OFFSET);
return 0;
}
static int mvebu_devbus_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *node = pdev->dev.of_node;
struct device_node *parent;
struct devbus *devbus;
struct resource *res;
struct clk *clk;
unsigned long rate;
const __be32 *ranges;
int err, cs;
int addr_cells, p_addr_cells, size_cells;
int ranges_len, tuple_len;
u32 base, size;
devbus = devm_kzalloc(&pdev->dev, sizeof(struct devbus), GFP_KERNEL);
if (!devbus)
return -ENOMEM;
devbus->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
devbus->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(devbus->base))
return PTR_ERR(devbus->base);
clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
clk_prepare_enable(clk);
/*
* Obtain clock period in picoseconds,
* we need this in order to convert timing
* parameters from cycles to picoseconds.
*/
rate = clk_get_rate(clk) / 1000;
devbus->tick_ps = 1000000000 / rate;
/* Read the device tree node and set the new timing parameters */
err = devbus_set_timing_params(devbus, node);
if (err < 0)
return err;
/*
* Allocate an address window for this device.
* If the device probing fails, then we won't be able to
* remove the allocated address decoding window.
*
* FIXME: This is only a temporary hack! We need to do this here
* because we still don't have device tree bindings for mbus.
* Once that support is added, we will declare these address windows
* statically in the device tree, and remove the window configuration
* from here.
*/
/*
* Get the CS to choose the window string.
* This is a bit hacky, but it will be removed once the
* address windows are declared in the device tree.
*/
cs = (((unsigned long)devbus->base) % 0x400) / 8;
/*
* Parse 'ranges' property to obtain a (base,size) window tuple.
* This will be removed once the address windows
* are declared in the device tree.
*/
parent = of_get_parent(node);
if (!parent)
return -EINVAL;
p_addr_cells = of_n_addr_cells(parent);
of_node_put(parent);
addr_cells = of_n_addr_cells(node);
size_cells = of_n_size_cells(node);
tuple_len = (p_addr_cells + addr_cells + size_cells) * sizeof(__be32);
ranges = of_get_property(node, "ranges", &ranges_len);
if (ranges == NULL || ranges_len != tuple_len)
return -EINVAL;
base = of_translate_address(node, ranges + addr_cells);
if (base == OF_BAD_ADDR)
return -EINVAL;
size = of_read_number(ranges + addr_cells + p_addr_cells, size_cells);
/*
* Create an mbus address windows.
* FIXME: Remove this, together with the above code, once the
* address windows are declared in the device tree.
*/
err = mvebu_mbus_add_window(devbus_wins[cs], base, size);
if (err < 0)
return err;
/*
* We need to create a child device explicitly from here to
* guarantee that the child will be probed after the timing
* parameters for the bus are written.
*/
err = of_platform_populate(node, NULL, NULL, dev);
if (err < 0) {
mvebu_mbus_del_window(base, size);
return err;
}
return 0;
}
static const struct of_device_id mvebu_devbus_of_match[] = {
{ .compatible = "marvell,mvebu-devbus" },
{},
};
MODULE_DEVICE_TABLE(of, mvebu_devbus_of_match);
static struct platform_driver mvebu_devbus_driver = {
.probe = mvebu_devbus_probe,
.driver = {
.name = "mvebu-devbus",
.owner = THIS_MODULE,
.of_match_table = mvebu_devbus_of_match,
},
};
static int __init mvebu_devbus_init(void)
{
return platform_driver_register(&mvebu_devbus_driver);
}
module_init(mvebu_devbus_init);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
MODULE_DESCRIPTION("Marvell EBU SoC Device Bus controller");