#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;
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;
/* 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, 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)
.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,
};
projects / karo-tx-linux.git / blobdiff