| /* |
| * 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/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; |
| |
| if (!pdev->dev.of_node) |
| return -ENODEV; |
| |
| match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node); |
| drv_data = match->data; |
| |
| return dw_mci_pltfm_register(pdev, drv_data); |
| } |
| |
| static struct platform_driver dw_mci_rockchip_pltfm_driver = { |
| .probe = dw_mci_rockchip_probe, |
| .remove = dw_mci_pltfm_remove, |
| .driver = { |
| .name = "dwmmc_rockchip", |
| .of_match_table = dw_mci_rockchip_match, |
| .pm = &dw_mci_pltfm_pmops, |
| }, |
| }; |
| |
| 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"); |