linux/drivers/bus/da8xx-mstpri.c

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/*
* TI da8xx master peripheral priority driver
*
* Copyright (C) 2016 BayLibre SAS
*
* Author:
* Bartosz Golaszewski <bgolaszewski@baylibre.com>
*
* 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/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/regmap.h>
/*
* REVISIT: Linux doesn't have a good framework for the kind of performance
* knobs this driver controls. We can't use device tree properties as it deals
* with hardware configuration rather than description. We also don't want to
* commit to maintaining some random sysfs attributes.
*
* For now we just hardcode the register values for the boards that need
* some changes (as is the case for the LCD controller on da850-lcdk - the
* first board we support here). When linux gets an appropriate framework,
* we'll easily convert the driver to it.
*/
#define DA8XX_MSTPRI0_OFFSET 0
#define DA8XX_MSTPRI1_OFFSET 4
#define DA8XX_MSTPRI2_OFFSET 8
enum {
DA8XX_MSTPRI_ARM_I = 0,
DA8XX_MSTPRI_ARM_D,
DA8XX_MSTPRI_UPP,
DA8XX_MSTPRI_SATA,
DA8XX_MSTPRI_PRU0,
DA8XX_MSTPRI_PRU1,
DA8XX_MSTPRI_EDMA30TC0,
DA8XX_MSTPRI_EDMA30TC1,
DA8XX_MSTPRI_EDMA31TC0,
DA8XX_MSTPRI_VPIF_DMA_0,
DA8XX_MSTPRI_VPIF_DMA_1,
DA8XX_MSTPRI_EMAC,
DA8XX_MSTPRI_USB0CFG,
DA8XX_MSTPRI_USB0CDMA,
DA8XX_MSTPRI_UHPI,
DA8XX_MSTPRI_USB1,
DA8XX_MSTPRI_LCDC,
};
struct da8xx_mstpri_descr {
int reg;
int shift;
int mask;
};
static const struct da8xx_mstpri_descr da8xx_mstpri_priority_list[] = {
[DA8XX_MSTPRI_ARM_I] = {
.reg = DA8XX_MSTPRI0_OFFSET,
.shift = 0,
.mask = 0x0000000f,
},
[DA8XX_MSTPRI_ARM_D] = {
.reg = DA8XX_MSTPRI0_OFFSET,
.shift = 4,
.mask = 0x000000f0,
},
[DA8XX_MSTPRI_UPP] = {
.reg = DA8XX_MSTPRI0_OFFSET,
.shift = 16,
.mask = 0x000f0000,
},
[DA8XX_MSTPRI_SATA] = {
.reg = DA8XX_MSTPRI0_OFFSET,
.shift = 20,
.mask = 0x00f00000,
},
[DA8XX_MSTPRI_PRU0] = {
.reg = DA8XX_MSTPRI1_OFFSET,
.shift = 0,
.mask = 0x0000000f,
},
[DA8XX_MSTPRI_PRU1] = {
.reg = DA8XX_MSTPRI1_OFFSET,
.shift = 4,
.mask = 0x000000f0,
},
[DA8XX_MSTPRI_EDMA30TC0] = {
.reg = DA8XX_MSTPRI1_OFFSET,
.shift = 8,
.mask = 0x00000f00,
},
[DA8XX_MSTPRI_EDMA30TC1] = {
.reg = DA8XX_MSTPRI1_OFFSET,
.shift = 12,
.mask = 0x0000f000,
},
[DA8XX_MSTPRI_EDMA31TC0] = {
.reg = DA8XX_MSTPRI1_OFFSET,
.shift = 16,
.mask = 0x000f0000,
},
[DA8XX_MSTPRI_VPIF_DMA_0] = {
.reg = DA8XX_MSTPRI1_OFFSET,
.shift = 24,
.mask = 0x0f000000,
},
[DA8XX_MSTPRI_VPIF_DMA_1] = {
.reg = DA8XX_MSTPRI1_OFFSET,
.shift = 28,
.mask = 0xf0000000,
},
[DA8XX_MSTPRI_EMAC] = {
.reg = DA8XX_MSTPRI2_OFFSET,
.shift = 0,
.mask = 0x0000000f,
},
[DA8XX_MSTPRI_USB0CFG] = {
.reg = DA8XX_MSTPRI2_OFFSET,
.shift = 8,
.mask = 0x00000f00,
},
[DA8XX_MSTPRI_USB0CDMA] = {
.reg = DA8XX_MSTPRI2_OFFSET,
.shift = 12,
.mask = 0x0000f000,
},
[DA8XX_MSTPRI_UHPI] = {
.reg = DA8XX_MSTPRI2_OFFSET,
.shift = 20,
.mask = 0x00f00000,
},
[DA8XX_MSTPRI_USB1] = {
.reg = DA8XX_MSTPRI2_OFFSET,
.shift = 24,
.mask = 0x0f000000,
},
[DA8XX_MSTPRI_LCDC] = {
.reg = DA8XX_MSTPRI2_OFFSET,
.shift = 28,
.mask = 0xf0000000,
},
};
struct da8xx_mstpri_priority {
int which;
u32 val;
};
struct da8xx_mstpri_board_priorities {
const char *board;
const struct da8xx_mstpri_priority *priorities;
size_t numprio;
};
/*
* Default memory settings of da850 do not meet the throughput/latency
* requirements of tilcdc. This results in the image displayed being
* incorrect and the following warning being displayed by the LCDC
* drm driver:
*
* tilcdc da8xx_lcdc.0: tilcdc_crtc_irq(0x00000020): FIFO underfow
*/
static const struct da8xx_mstpri_priority da850_lcdk_priorities[] = {
{
.which = DA8XX_MSTPRI_LCDC,
.val = 0,
},
{
.which = DA8XX_MSTPRI_EDMA30TC1,
.val = 0,
},
{
.which = DA8XX_MSTPRI_EDMA30TC0,
.val = 1,
},
};
static const struct da8xx_mstpri_board_priorities da8xx_mstpri_board_confs[] = {
{
.board = "ti,da850-lcdk",
.priorities = da850_lcdk_priorities,
.numprio = ARRAY_SIZE(da850_lcdk_priorities),
},
};
static const struct da8xx_mstpri_board_priorities *
da8xx_mstpri_get_board_prio(void)
{
const struct da8xx_mstpri_board_priorities *board_prio;
int i;
for (i = 0; i < ARRAY_SIZE(da8xx_mstpri_board_confs); i++) {
board_prio = &da8xx_mstpri_board_confs[i];
if (of_machine_is_compatible(board_prio->board))
return board_prio;
}
return NULL;
}
static int da8xx_mstpri_probe(struct platform_device *pdev)
{
const struct da8xx_mstpri_board_priorities *prio_list;
const struct da8xx_mstpri_descr *prio_descr;
const struct da8xx_mstpri_priority *prio;
struct device *dev = &pdev->dev;
struct resource *res;
void __iomem *mstpri;
u32 reg;
int i;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mstpri = devm_ioremap_resource(dev, res);
if (IS_ERR(mstpri)) {
dev_err(dev, "unable to map MSTPRI registers\n");
return PTR_ERR(mstpri);
}
prio_list = da8xx_mstpri_get_board_prio();
if (!prio_list) {
dev_err(dev, "no master priorities defined for this board\n");
return -EINVAL;
}
for (i = 0; i < prio_list->numprio; i++) {
prio = &prio_list->priorities[i];
prio_descr = &da8xx_mstpri_priority_list[prio->which];
if (prio_descr->reg + sizeof(u32) > resource_size(res)) {
dev_warn(dev, "register offset out of range\n");
continue;
}
reg = readl(mstpri + prio_descr->reg);
reg &= ~prio_descr->mask;
reg |= prio->val << prio_descr->shift;
writel(reg, mstpri + prio_descr->reg);
}
return 0;
}
static const struct of_device_id da8xx_mstpri_of_match[] = {
{ .compatible = "ti,da850-mstpri", },
{ },
};
static struct platform_driver da8xx_mstpri_driver = {
.probe = da8xx_mstpri_probe,
.driver = {
.name = "da8xx-mstpri",
.of_match_table = da8xx_mstpri_of_match,
},
};
module_platform_driver(da8xx_mstpri_driver);
MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
MODULE_DESCRIPTION("TI da8xx master peripheral priority driver");
MODULE_LICENSE("GPL v2");