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linux/drivers/memory/pl172.c
Uwe Kleine-König 3fd269e74f amba: Make the remove callback return void 
All amba drivers return 0 in their remove callback. Together with the
driver core ignoring the return value anyhow, it doesn't make sense to
return a value here.

Change the remove prototype to return void, which makes it explicit that
returning an error value doesn't work as expected. This simplifies changing
the core remove callback to return void, too.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org> # for drivers/memory
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> # for hwtracing/coresight
Acked-By: Vinod Koul <vkoul@kernel.org> # for dmaengine
Acked-by: Guenter Roeck <linux@roeck-us.net> # for watchdog
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Takashi Iwai <tiwai@suse.de> # for sound
Acked-by: Vladimir Zapolskiy <vz@mleia.com> # for memory/pl172
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210126165835.687514-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2021-02-02 14:25:50 +01:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Memory controller driver for ARM PrimeCell PL172
* PrimeCell MultiPort Memory Controller (PL172)
*
* Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
*
* Based on:
* TI AEMIF driver, Copyright (C) 2010 - 2013 Texas Instruments Inc.
*/
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/time.h>
#define MPMC_STATIC_CFG(n) (0x200 + 0x20 * (n))
#define MPMC_STATIC_CFG_MW_8BIT 0x0
#define MPMC_STATIC_CFG_MW_16BIT 0x1
#define MPMC_STATIC_CFG_MW_32BIT 0x2
#define MPMC_STATIC_CFG_PM BIT(3)
#define MPMC_STATIC_CFG_PC BIT(6)
#define MPMC_STATIC_CFG_PB BIT(7)
#define MPMC_STATIC_CFG_EW BIT(8)
#define MPMC_STATIC_CFG_B BIT(19)
#define MPMC_STATIC_CFG_P BIT(20)
#define MPMC_STATIC_WAIT_WEN(n) (0x204 + 0x20 * (n))
#define MPMC_STATIC_WAIT_WEN_MAX 0x0f
#define MPMC_STATIC_WAIT_OEN(n) (0x208 + 0x20 * (n))
#define MPMC_STATIC_WAIT_OEN_MAX 0x0f
#define MPMC_STATIC_WAIT_RD(n) (0x20c + 0x20 * (n))
#define MPMC_STATIC_WAIT_RD_MAX 0x1f
#define MPMC_STATIC_WAIT_PAGE(n) (0x210 + 0x20 * (n))
#define MPMC_STATIC_WAIT_PAGE_MAX 0x1f
#define MPMC_STATIC_WAIT_WR(n) (0x214 + 0x20 * (n))
#define MPMC_STATIC_WAIT_WR_MAX 0x1f
#define MPMC_STATIC_WAIT_TURN(n) (0x218 + 0x20 * (n))
#define MPMC_STATIC_WAIT_TURN_MAX 0x0f
/* Maximum number of static chip selects */
#define PL172_MAX_CS 4
struct pl172_data {
void __iomem *base;
unsigned long rate;
struct clk *clk;
};
static int pl172_timing_prop(struct amba_device *adev,
const struct device_node *np, const char *name,
u32 reg_offset, u32 max, int start)
{
struct pl172_data *pl172 = amba_get_drvdata(adev);
int cycles;
u32 val;
if (!of_property_read_u32(np, name, &val)) {
cycles = DIV_ROUND_UP(val * pl172->rate, NSEC_PER_MSEC) - start;
if (cycles < 0) {
cycles = 0;
} else if (cycles > max) {
dev_err(&adev->dev, "%s timing too tight\n", name);
return -EINVAL;
}
writel(cycles, pl172->base + reg_offset);
}
dev_dbg(&adev->dev, "%s: %u cycle(s)\n", name, start +
readl(pl172->base + reg_offset));
return 0;
}
static int pl172_setup_static(struct amba_device *adev,
struct device_node *np, u32 cs)
{
struct pl172_data *pl172 = amba_get_drvdata(adev);
u32 cfg;
int ret;
/* MPMC static memory configuration */
if (!of_property_read_u32(np, "mpmc,memory-width", &cfg)) {
if (cfg == 8) {
cfg = MPMC_STATIC_CFG_MW_8BIT;
} else if (cfg == 16) {
cfg = MPMC_STATIC_CFG_MW_16BIT;
} else if (cfg == 32) {
cfg = MPMC_STATIC_CFG_MW_32BIT;
} else {
dev_err(&adev->dev, "invalid memory width cs%u\n", cs);
return -EINVAL;
}
} else {
dev_err(&adev->dev, "memory-width property required\n");
return -EINVAL;
}
if (of_property_read_bool(np, "mpmc,async-page-mode"))
cfg |= MPMC_STATIC_CFG_PM;
if (of_property_read_bool(np, "mpmc,cs-active-high"))
cfg |= MPMC_STATIC_CFG_PC;
if (of_property_read_bool(np, "mpmc,byte-lane-low"))
cfg |= MPMC_STATIC_CFG_PB;
if (of_property_read_bool(np, "mpmc,extended-wait"))
cfg |= MPMC_STATIC_CFG_EW;
if (amba_part(adev) == 0x172 &&
of_property_read_bool(np, "mpmc,buffer-enable"))
cfg |= MPMC_STATIC_CFG_B;
if (of_property_read_bool(np, "mpmc,write-protect"))
cfg |= MPMC_STATIC_CFG_P;
writel(cfg, pl172->base + MPMC_STATIC_CFG(cs));
dev_dbg(&adev->dev, "mpmc static config cs%u: 0x%08x\n", cs, cfg);
/* MPMC static memory timing */
ret = pl172_timing_prop(adev, np, "mpmc,write-enable-delay",
MPMC_STATIC_WAIT_WEN(cs),
MPMC_STATIC_WAIT_WEN_MAX, 1);
if (ret)
goto fail;
ret = pl172_timing_prop(adev, np, "mpmc,output-enable-delay",
MPMC_STATIC_WAIT_OEN(cs),
MPMC_STATIC_WAIT_OEN_MAX, 0);
if (ret)
goto fail;
ret = pl172_timing_prop(adev, np, "mpmc,read-access-delay",
MPMC_STATIC_WAIT_RD(cs),
MPMC_STATIC_WAIT_RD_MAX, 1);
if (ret)
goto fail;
ret = pl172_timing_prop(adev, np, "mpmc,page-mode-read-delay",
MPMC_STATIC_WAIT_PAGE(cs),
MPMC_STATIC_WAIT_PAGE_MAX, 1);
if (ret)
goto fail;
ret = pl172_timing_prop(adev, np, "mpmc,write-access-delay",
MPMC_STATIC_WAIT_WR(cs),
MPMC_STATIC_WAIT_WR_MAX, 2);
if (ret)
goto fail;
ret = pl172_timing_prop(adev, np, "mpmc,turn-round-delay",
MPMC_STATIC_WAIT_TURN(cs),
MPMC_STATIC_WAIT_TURN_MAX, 1);
if (ret)
goto fail;
return 0;
fail:
dev_err(&adev->dev, "failed to configure cs%u\n", cs);
return ret;
}
static int pl172_parse_cs_config(struct amba_device *adev,
struct device_node *np)
{
u32 cs;
if (!of_property_read_u32(np, "mpmc,cs", &cs)) {
if (cs >= PL172_MAX_CS) {
dev_err(&adev->dev, "cs%u invalid\n", cs);
return -EINVAL;
}
return pl172_setup_static(adev, np, cs);
}
dev_err(&adev->dev, "cs property required\n");
return -EINVAL;
}
static const char * const pl172_revisions[] = {"r1", "r2", "r2p3", "r2p4"};
static const char * const pl175_revisions[] = {"r1"};
static const char * const pl176_revisions[] = {"r0"};
static int pl172_probe(struct amba_device *adev, const struct amba_id *id)
{
struct device_node *child_np, *np = adev->dev.of_node;
struct device *dev = &adev->dev;
static const char *rev = "?";
struct pl172_data *pl172;
int ret;
if (amba_part(adev) == 0x172) {
if (amba_rev(adev) < ARRAY_SIZE(pl172_revisions))
rev = pl172_revisions[amba_rev(adev)];
} else if (amba_part(adev) == 0x175) {
if (amba_rev(adev) < ARRAY_SIZE(pl175_revisions))
rev = pl175_revisions[amba_rev(adev)];
} else if (amba_part(adev) == 0x176) {
if (amba_rev(adev) < ARRAY_SIZE(pl176_revisions))
rev = pl176_revisions[amba_rev(adev)];
}
dev_info(dev, "ARM PL%x revision %s\n", amba_part(adev), rev);
pl172 = devm_kzalloc(dev, sizeof(*pl172), GFP_KERNEL);
if (!pl172)
return -ENOMEM;
pl172->clk = devm_clk_get(dev, "mpmcclk");
if (IS_ERR(pl172->clk)) {
dev_err(dev, "no mpmcclk provided clock\n");
return PTR_ERR(pl172->clk);
}
ret = clk_prepare_enable(pl172->clk);
if (ret) {
dev_err(dev, "unable to mpmcclk enable clock\n");
return ret;
}
pl172->rate = clk_get_rate(pl172->clk) / MSEC_PER_SEC;
if (!pl172->rate) {
dev_err(dev, "unable to get mpmcclk clock rate\n");
ret = -EINVAL;
goto err_clk_enable;
}
ret = amba_request_regions(adev, NULL);
if (ret) {
dev_err(dev, "unable to request AMBA regions\n");
goto err_clk_enable;
}
pl172->base = devm_ioremap(dev, adev->res.start,
resource_size(&adev->res));
if (!pl172->base) {
dev_err(dev, "ioremap failed\n");
ret = -ENOMEM;
goto err_no_ioremap;
}
amba_set_drvdata(adev, pl172);
/*
* Loop through each child node, which represent a chip select, and
* configure parameters and timing. If successful; populate devices
* under that node.
*/
for_each_available_child_of_node(np, child_np) {
ret = pl172_parse_cs_config(adev, child_np);
if (ret)
continue;
of_platform_populate(child_np, NULL, NULL, dev);
}
return 0;
err_no_ioremap:
amba_release_regions(adev);
err_clk_enable:
clk_disable_unprepare(pl172->clk);
return ret;
}
static void pl172_remove(struct amba_device *adev)
{
struct pl172_data *pl172 = amba_get_drvdata(adev);
clk_disable_unprepare(pl172->clk);
amba_release_regions(adev);
}
static const struct amba_id pl172_ids[] = {
/* PrimeCell MPMC PL172, EMC found on NXP LPC18xx and LPC43xx */
{
.id = 0x07041172,
.mask = 0x3f0fffff,
},
/* PrimeCell MPMC PL175, EMC found on NXP LPC32xx */
{
.id = 0x07041175,
.mask = 0x3f0fffff,
},
/* PrimeCell MPMC PL176 */
{
.id = 0x89041176,
.mask = 0xff0fffff,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl172_ids);
static struct amba_driver pl172_driver = {
.drv = {
.name = "memory-pl172",
},
.probe = pl172_probe,
.remove = pl172_remove,
.id_table = pl172_ids,
};
module_amba_driver(pl172_driver);
MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
MODULE_DESCRIPTION("PL172 Memory Controller Driver");
MODULE_LICENSE("GPL v2");
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