diff options
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/dw_mmc-rockchip.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c index bc76aa22473e..4b3650f7d43f 100644 --- a/drivers/mmc/host/dw_mmc-rockchip.c +++ b/drivers/mmc/host/dw_mmc-rockchip.c @@ -13,12 +13,19 @@ #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_rockchip_prepare_command(struct dw_mci *host, u32 *cmdr) { *cmdr |= SDMMC_CMD_USE_HOLD_REG; @@ -33,6 +40,7 @@ static int dw_mci_rk3288_setup_clock(struct dw_mci *host) 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; @@ -66,6 +74,158 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios) /* 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); +} + +#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) +{ + 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); + + 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) @@ -95,6 +255,8 @@ static const struct dw_mci_drv_data rk3288_drv_data = { .caps = dw_mci_rk3288_dwmmc_caps, .prepare_command = dw_mci_rockchip_prepare_command, .set_ios = dw_mci_rk3288_set_ios, + .execute_tuning = dw_mci_rk3288_execute_tuning, + .parse_dt = dw_mci_rk3288_parse_dt, .setup_clock = dw_mci_rk3288_setup_clock, .init = dw_mci_rockchip_init, }; |