/*
* Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/mmc/host.h>
#include <linux/mmc/dw_mmc.h>
#include <linux/of_address.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include "dw_mmc.h"
#include "dw_mmc-pltfm.h"
#define RK3288_CLKGEN_DIV 2
struct dw_mci_rockchip_priv_data {
struct clk *drv_clk;
struct clk *sample_clk;
int default_sample_phase;
};
static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
{
struct dw_mci_rockchip_priv_data *priv = host->priv;
int ret;
unsigned int cclkin;
u32 bus_hz;
if (ios->clock == 0)
return;
/*
* cclkin: source clock of mmc controller
* bus_hz: card interface clock generated by CLKGEN
* bus_hz = cclkin / RK3288_CLKGEN_DIV
* ios->clock = (div == 0) ? bus_hz : (bus_hz / (2 * div))
*
* Note: div can only be 0 or 1
* if DDR50 8bit mode(only emmc work in 8bit mode),
* div must be set 1
*/
if (ios->bus_width == MMC_BUS_WIDTH_8 &&
ios->timing == MMC_TIMING_MMC_DDR52)
cclkin = 2 * ios->clock * RK3288_CLKGEN_DIV;
else
cclkin = ios->clock * RK3288_CLKGEN_DIV;
ret = clk_set_rate(host->ciu_clk, cclkin);
if (ret)
dev_warn(host->dev, "failed to set rate %uHz\n", ios->clock);
bus_hz = clk_get_rate(host->ciu_clk) / RK3288_CLKGEN_DIV;
if (bus_hz != host->bus_hz) {
host->bus_hz = bus_hz;
/* force dw_mci_setup_bus() */
host->current_speed = 0;
}
/* Make sure we use phases which we can enumerate with */
if (!IS_ERR(priv->sample_clk))
clk_set_phase(priv->sample_clk, priv->default_sample_phase);
/*
* Set the drive phase offset based on speed mode to achieve hold times.
*
* NOTE: this is _not_ a value that is dynamically tuned and is also
* _not_ a value that will vary from board to board. It is a value
* that could vary between different SoC models if they had massively
* different output clock delays inside their dw_mmc IP block (delay_o),
* but since it's OK to overshoot a little we don't need to do complex
* calculations and can pick values that will just work for everyone.
*
* When picking values we'll stick with picking 0/90/180/270 since
* those can be made very accurately on all known Rockchip SoCs.
*
* Note that these values match values from the DesignWare Databook
* tables for the most part except for SDR12 and "ID mode". For those
* two modes the databook calculations assume a clock in of 50MHz. As
* seen above, we always use a clock in rate that is exactly the
* card's input clock (times RK3288_CLKGEN_DIV, but that gets divided
* back out before the controller sees it).
*
* From measurement of a single device, it appears that delay_o is
* about .5 ns. Since we try to leave a bit of margin, it's expected
* that numbers here will be fine even with much larger delay_o
* (the 1.4 ns assumed by the DesignWare Databook would result in the
* same results, for instance).
*/
if (!IS_ERR(priv->drv_clk)) {
int phase;
/*
* In almost all cases a 90 degree phase offset will provide
* sufficient hold times across all valid input clock rates
* assuming delay_o is not absurd for a given SoC. We'll use
* that as a default.
*/
phase = 90;
switch (ios->timing) {
case MMC_TIMING_MMC_DDR52:
/*
* Since clock in rate with MMC_DDR52 is doubled when
* bus width is 8 we need to double the phase offset
* to get the same timings.
*/
if (ios->bus_width == MMC_BUS_WIDTH_8)
phase = 180;
break;
case MMC_TIMING_UHS_SDR104:
case MMC_TIMING_MMC_HS200:
/*
* In the case of 150 MHz clock (typical max for
* Rockchip SoCs), 90 degree offset will add a delay
* of 1.67 ns. That will meet min hold time of .8 ns
* as long as clock output delay is < .87 ns. On
* SoCs measured this seems to be OK, but it doesn't
* hurt to give margin here, so we use 180.
*/
phase = 180;
break;
}
clk_set_phase(priv->drv_clk, phase);
}
}
#define NUM_PHASES 360
#define TUNING_ITERATION_TO_PHASE(i) (DIV_ROUND_UP((i) * 360, NUM_PHASES))
static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
{
struct dw_mci *host = slot->host;
struct dw_mci_rockchip_priv_data *priv = host->priv;
struct mmc_host *mmc = slot->mmc;
int ret = 0;
int i;
bool v, prev_v = 0, first_v;
struct range_t {
int start;
int end; /* inclusive */
};
struct range_t *ranges;
unsigned int range_count = 0;
int longest_range_len = -1;
int longest_range = -1;
int middle_phase;
if (IS_ERR(priv->sample_clk)) {
dev_err(host->dev, "Tuning clock (sample_clk) not defined.\n");
return -EIO;
}
ranges = kmalloc_array(NUM_PHASES / 2 + 1, sizeof(*ranges), GFP_KERNEL);
if (!ranges)
return -ENOMEM;
/* Try each phase and extract good ranges */
for (i = 0; i < NUM_PHASES; ) {
clk_set_phase(priv->sample_clk, TUNING_ITERATION_TO_PHASE(i));
v = !mmc_send_tuning(mmc, opcode, NULL);
if (i == 0)
first_v = v;
if ((!prev_v) && v) {
range_count++;
ranges[range_count-1].start = i;
}
if (v) {
ranges[range_count-1].end = i;
i++;
} else if (i == NUM_PHASES - 1) {
/* No extra skipping rules if we're at the end */
i++;
} else {
/*
* No need to check too close to an invalid
* one since testing bad phases is slow. Skip
* 20 degrees.
*/
i += DIV_ROUND_UP(20 * NUM_PHASES, 360);
/* Always test the last one */
if (i >= NUM_PHASES)
i = NUM_PHASES - 1;
}
prev_v = v;
}
if (range_count == 0) {
dev_warn(host->dev, "All phases bad!");
ret = -EIO;
goto free;
}
/* wrap around case, merge the end points */
if ((range_count > 1) && first_v && v) {
ranges[0].start = ranges[range_count-1].start;
range_count--;
}
if (ranges[0].start == 0 && ranges[0].end == NUM_PHASES - 1) {
clk_set_phase(priv->sample_clk, priv->default_sample_phase);
dev_info(host->dev, "All phases work, using default phase %d.",
priv->default_sample_phase);
goto free;
}
/* Find the longest range */
for (i = 0; i < range_count; i++) {
int len = (ranges[i].end - ranges[i].start + 1);
if (len < 0)
len += NUM_PHASES;
if (longest_range_len < len) {
longest_range_len = len;
longest_range = i;
}
dev_dbg(host->dev, "Good phase range %d-%d (%d len)\n",
TUNING_ITERATION_TO_PHASE(ranges[i].start),
TUNING_ITERATION_TO_PHASE(ranges[i].end),
len
);
}
dev_dbg(host->dev, "Best phase range %d-%d (%d len)\n",
TUNING_ITERATION_TO_PHASE(ranges[longest_range].start),
TUNING_ITERATION_TO_PHASE(ranges[longest_range].end),
longest_range_len
);
middle_phase = ranges[longest_range].start + longest_range_len / 2;
middle_phase %= NUM_PHASES;
dev_info(host->dev, "Successfully tuned phase to %d\n",
TUNING_ITERATION_TO_PHASE(middle_phase));
clk_set_phase(priv->sample_clk,
TUNING_ITERATION_TO_PHASE(middle_phase));
free:
kfree(ranges);
return ret;
}
static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
{
struct device_node *np = host->dev->of_node;
struct dw_mci_rockchip_priv_data *priv;
priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
if (of_property_read_u32(np, "rockchip,default-sample-phase",
&priv->default_sample_phase))
priv->default_sample_phase = 0;
priv->drv_clk = devm_clk_get(host->dev, "ciu-drive");
if (IS_ERR(priv->drv_clk))
dev_dbg(host->dev, "ciu_drv not available\n");
priv->sample_clk = devm_clk_get(host->dev, "ciu-sample");
if (IS_ERR(priv->sample_clk))
dev_dbg(host->dev, "ciu_sample not available\n");
host->priv = priv;
return 0;
}
static int dw_mci_rockchip_init(struct dw_mci *host)
{
/* It is slot 8 on Rockchip SoCs */
host->sdio_id0 = 8;
if (of_device_is_compatible(host->dev->of_node,
"rockchip,rk3288-dw-mshc"))
host->bus_hz /= RK3288_CLKGEN_DIV;
return 0;
}
/* Common capabilities of RK3288 SoC */
static unsigned long dw_mci_rk3288_dwmmc_caps[4] = {
MMC_CAP_CMD23,
MMC_CAP_CMD23,
MMC_CAP_CMD23,
MMC_CAP_CMD23,
};
static const struct dw_mci_drv_data rk2928_drv_data = {
.init = dw_mci_rockchip_init,
};
static const struct dw_mci_drv_data rk3288_drv_data = {
.caps = dw_mci_rk3288_dwmmc_caps,
.set_ios = dw_mci_rk3288_set_ios,
.execute_tuning = dw_mci_rk3288_execute_tuning,
.parse_dt = dw_mci_rk3288_parse_dt,
.init = dw_mci_rockchip_init,
};
static const struct of_device_id dw_mci_rockchip_match[] = {
{ .compatible = "rockchip,rk2928-dw-mshc",
.data = &rk2928_drv_data },
{ .compatible = "rockchip,rk3288-dw-mshc",
.data = &rk3288_drv_data },
{},
};
MODULE_DEVICE_TABLE(of, dw_mci_rockchip_match);
static int dw_mci_rockchip_probe(struct platform_device *pdev)
{
const struct dw_mci_drv_data *drv_data;
const struct of_device_id *match;
int ret;
if (!pdev->dev.of_node)
return -ENODEV;
match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node);
drv_data = match->data;
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
pm_runtime_use_autosuspend(&pdev->dev);
ret = dw_mci_pltfm_register(pdev, drv_data);
if (ret) {
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
return ret;
}
pm_runtime_put_autosuspend(&pdev->dev);
return 0;
}
static int dw_mci_rockchip_remove(struct platform_device *pdev)
{
pm_runtime_get_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
return dw_mci_pltfm_remove(pdev);
}
static const struct dev_pm_ops dw_mci_rockchip_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend,
dw_mci_runtime_resume,
NULL)
};
static struct platform_driver dw_mci_rockchip_pltfm_driver = {
.probe = dw_mci_rockchip_probe,
.remove = dw_mci_rockchip_remove,
.driver = {
.name = "dwmmc_rockchip",
.of_match_table = dw_mci_rockchip_match,
.pm = &dw_mci_rockchip_dev_pm_ops,
},
};
module_platform_driver(dw_mci_rockchip_pltfm_driver);
MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
MODULE_DESCRIPTION("Rockchip Specific DW-MSHC Driver Extension");
MODULE_ALIAS("platform:dwmmc_rockchip");
MODULE_LICENSE("GPL v2");
