diff options
Diffstat (limited to 'drivers/mmc/host/dw_mmc-rockchip.c')
| -rw-r--r-- | drivers/mmc/host/dw_mmc-rockchip.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c new file mode 100644 index 0000000000..b07190ba4b --- /dev/null +++ b/drivers/mmc/host/dw_mmc-rockchip.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/mmc/host.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 + +static const unsigned int freqs[] = { 100000, 200000, 300000, 400000 }; + +struct dw_mci_rockchip_priv_data { + struct clk *drv_clk; + struct clk *sample_clk; + int default_sample_phase; + int num_phases; +}; + +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, but div must be set to 1 for eMMC + * DDR52 8-bit mode. + */ + 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 err: %d\n", cclkin, ret); + + 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) && ios->timing <= MMC_TIMING_SD_HS) + 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 TUNING_ITERATION_TO_PHASE(i, num_phases) \ + (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(priv->num_phases / 2 + 1, + sizeof(*ranges), GFP_KERNEL); + if (!ranges) + return -ENOMEM; + + /* Try each phase and extract good ranges */ + for (i = 0; i < priv->num_phases; ) { + clk_set_phase(priv->sample_clk, + TUNING_ITERATION_TO_PHASE(i, priv->num_phases)); + + 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 == priv->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 * priv->num_phases, 360); + + /* Always test the last one */ + if (i >= priv->num_phases) + i = priv->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 == priv->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 += priv->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, + priv->num_phases), + TUNING_ITERATION_TO_PHASE(ranges[i].end, + priv->num_phases), + len + ); + } + + dev_dbg(host->dev, "Best phase range %d-%d (%d len)\n", + TUNING_ITERATION_TO_PHASE(ranges[longest_range].start, + priv->num_phases), + TUNING_ITERATION_TO_PHASE(ranges[longest_range].end, + priv->num_phases), + longest_range_len + ); + + middle_phase = ranges[longest_range].start + longest_range_len / 2; + middle_phase %= priv->num_phases; + dev_info(host->dev, "Successfully tuned phase to %d\n", + TUNING_ITERATION_TO_PHASE(middle_phase, priv->num_phases)); + + clk_set_phase(priv->sample_clk, + TUNING_ITERATION_TO_PHASE(middle_phase, + priv->num_phases)); + +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,desired-num-phases", + &priv->num_phases)) + priv->num_phases = 360; + + 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-drive 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) +{ + int ret, i; + + /* 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; + + /* clock driver will fail if the clock is less than the lowest source clock + * divided by the internal clock divider. Test for the lowest available + * clock and set the minimum freq to clock / clock divider. + */ + + for (i = 0; i < ARRAY_SIZE(freqs); i++) { + ret = clk_round_rate(host->ciu_clk, freqs[i] * RK3288_CLKGEN_DIV); + if (ret > 0) { + host->minimum_speed = ret / RK3288_CLKGEN_DIV; + break; + } + } + if (ret < 0) + dev_warn(host->dev, "no valid minimum freq: %d\n", ret); + } + + return 0; +} + +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 = { + .common_caps = MMC_CAP_CMD23, + .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 void 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); + + 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_new = dw_mci_rockchip_remove, + .driver = { + .name = "dwmmc_rockchip", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .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"); |