[PATCH 6.9 150/374] mmc: sdhci_am654: Add OTAP/ITAP delay enable

Greg Kroah-Hartman
2024-06-06T14:09:34Z

From: Judith Mendez <jm@ti.com>

[ Upstream commit 387c1bf7dce0dfea02080c8bdb066b5209e92155 ]

Currently the OTAP/ITAP delay enable functionality is incorrect in
the am654_set_clock function. The OTAP delay is not enabled when
timing < SDR25 bus speed mode. The ITAP delay is not enabled for
timings that do not carry out tuning.

Add this OTAP/ITAP delay functionality according to the datasheet
[1] OTAPDLYENA and ITAPDLYENA for MMC0.

[1] https://www.ti.com/lit/ds/symlink/am62p.pdf

Fixes: 8ee5fc0e0b3b ("mmc: sdhci_am654: Update OTAPDLY writes")
Signed-off-by: Judith Mendez <jm@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20240320223837.959900-4-jm@ti.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mmc/host/sdhci_am654.c | 40 ++++++++++++++++++++++------------
1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index cfb614d0b42b4..888bfda0ebc0e 100644
--- a/drivers/mmc/host/sdhci_am654.c
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -143,6 +143,7 @@ struct sdhci_am654_data {
struct regmap *base;
int otap_del_sel[ARRAY_SIZE(td)];
int itap_del_sel[ARRAY_SIZE(td)];
+ u32 itap_del_ena[ARRAY_SIZE(td)];
int clkbuf_sel;
int trm_icp;
int drv_strength;
@@ -239,11 +240,13 @@ static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned int clock)
}

static void sdhci_am654_write_itapdly(struct sdhci_am654_data *sdhci_am654,
- u32 itapdly)
+ u32 itapdly, u32 enable)
{
/* Set ITAPCHGWIN before writing to ITAPDLY */
regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK,
1 << ITAPCHGWIN_SHIFT);
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
+ enable << ITAPDLYENA_SHIFT);
regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYSEL_MASK,
itapdly << ITAPDLYSEL_SHIFT);
regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK, 0);
@@ -260,8 +263,8 @@ static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data *sdhci_am654,
mask = SELDLYTXCLK_MASK | SELDLYRXCLK_MASK;
regmap_update_bits(sdhci_am654->base, PHY_CTRL5, mask, val);

- sdhci_am654_write_itapdly(sdhci_am654,
- sdhci_am654->itap_del_sel[timing]);
+ sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
+ sdhci_am654->itap_del_ena[timing]);
}

static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
@@ -270,7 +273,6 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
unsigned char timing = host->mmc->ios.timing;
u32 otap_del_sel;
- u32 otap_del_ena;
u32 mask, val;

regmap_update_bits(sdhci_am654->base, PHY_CTRL1, ENDLL_MASK, 0);
@@ -279,10 +281,9 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)

/* Setup DLL Output TAP delay */
otap_del_sel = sdhci_am654->otap_del_sel[timing];
- otap_del_ena = (timing > MMC_TIMING_UHS_SDR25) ? 1 : 0;

mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
- val = (otap_del_ena << OTAPDLYENA_SHIFT) |
+ val = (0x1 << OTAPDLYENA_SHIFT) |
(otap_del_sel << OTAPDLYSEL_SHIFT);

/* Write to STRBSEL for HS400 speed mode */
@@ -300,7 +301,8 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
if (timing > MMC_TIMING_UHS_SDR25 && clock >= CLOCK_TOO_SLOW_HZ) {
sdhci_am654_setup_dll(host, clock);
sdhci_am654->dll_enable = true;
- sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing]);
+ sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
+ sdhci_am654->itap_del_ena[timing]);
} else {
sdhci_am654_setup_delay_chain(sdhci_am654, timing);
sdhci_am654->dll_enable = false;
@@ -317,6 +319,7 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
unsigned char timing = host->mmc->ios.timing;
u32 otap_del_sel;
+ u32 itap_del_ena;
u32 mask, val;

/* Setup DLL Output TAP delay */
@@ -325,6 +328,12 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
val = (0x1 << OTAPDLYENA_SHIFT) |
(otap_del_sel << OTAPDLYSEL_SHIFT);
+
+ itap_del_ena = sdhci_am654->itap_del_ena[timing];
+
+ mask |= ITAPDLYENA_MASK;
+ val |= (itap_del_ena << ITAPDLYENA_SHIFT);
+
regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);

regmap_update_bits(sdhci_am654->base, PHY_CTRL5, CLKBUFSEL_MASK,
@@ -478,6 +487,7 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+ unsigned char timing = host->mmc->ios.timing;
struct window fail_window[ITAPDLY_LENGTH];
u8 curr_pass, itap;
u8 fail_index = 0;
@@ -486,11 +496,10 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
memset(fail_window, 0, sizeof(fail_window));

/* Enable ITAPDLY */
- regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
- 1 << ITAPDLYENA_SHIFT);
+ sdhci_am654->itap_del_ena[timing] = 0x1;

for (itap = 0; itap < ITAPDLY_LENGTH; itap++) {
- sdhci_am654_write_itapdly(sdhci_am654, itap);
+ sdhci_am654_write_itapdly(sdhci_am654, itap, sdhci_am654->itap_del_ena[timing]);

curr_pass = !mmc_send_tuning(host->mmc, opcode, NULL);

@@ -514,7 +523,7 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
itap = sdhci_am654_calculate_itap(host, fail_window, fail_index,
sdhci_am654->dll_enable);

- sdhci_am654_write_itapdly(sdhci_am654, itap);
+ sdhci_am654_write_itapdly(sdhci_am654, itap, sdhci_am654->itap_del_ena[timing]);

return 0;
}
@@ -663,9 +672,12 @@ static int sdhci_am654_get_otap_delay(struct sdhci_host *host,
host->mmc->caps2 &= ~td[i].capability;
}

- if (td[i].itap_binding)
- device_property_read_u32(dev, td[i].itap_binding,
- &sdhci_am654->itap_del_sel[i]);
+ if (td[i].itap_binding) {
+ ret = device_property_read_u32(dev, td[i].itap_binding,
+ &sdhci_am654->itap_del_sel[i]);
+ if (!ret)
+ sdhci_am654->itap_del_ena[i] = 0x1;
+ }
}

return 0;
--
2.43.0