From: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
Add an odd clock divider capability available from v5xx. It also involves
changing the clock divider calculation.
Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
---
drivers/mmc/host/atmel-mci-regs.h | 1 +
drivers/mmc/host/atmel-mci.c | 48 ++++++++++++++++++++++--------------
2 files changed, 30 insertions(+), 19 deletions(-)
diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h
index 000b3ad..787aba1 100644
--- a/drivers/mmc/host/atmel-mci-regs.h
+++ b/drivers/mmc/host/atmel-mci-regs.h
@@ -31,6 +31,7 @@
# define ATMCI_MR_PDCFBYTE ( 1 << 13) /* Force Byte Transfer */
# define ATMCI_MR_PDCPADV ( 1 << 14) /* Padding Value */
# define ATMCI_MR_PDCMODE ( 1 << 15) /* PDC-oriented Mode */
+# define ATMCI_MR_CLKODD(x) ((x) << 16) /* LSB of Clock Divider */
#define ATMCI_DTOR 0x0008 /* Data Timeout */
# define ATMCI_DTOCYC(x) ((x) << 0) /* Data Timeout Cycles */
# define ATMCI_DTOMUL(x) ((x) << 4) /* Data Timeout Multiplier */
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 9dcb236..75e28c0 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -76,6 +76,7 @@ struct atmel_mci_caps {
bool has_cstor_reg;
bool has_highspeed;
bool has_rwproof;
+ bool has_odd_clk_div;
};
struct atmel_mci_dma {
@@ -1124,16 +1125,27 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
}
/* Calculate clock divider */
- clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
- if (clkdiv > 255) {
- dev_warn(&mmc->class_dev,
- "clock %u too slow; using %lu\n",
- clock_min, host->bus_hz / (2 * 256));
- clkdiv = 255;
+ if (host->caps.has_odd_clk_div) {
+ clkdiv = DIV_ROUND_UP(host->bus_hz, clock_min) - 2;
+ if (clkdiv > 511) {
+ dev_warn(&mmc->class_dev,
+ "clock %u too slow; using %lu\n",
+ clock_min, host->bus_hz / (511 + 2));
+ clkdiv = 511;
+ }
+ host->mode_reg = ATMCI_MR_CLKDIV(clkdiv >> 1)
+ | ATMCI_MR_CLKODD(clkdiv & 1);
+ } else {
+ clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
+ if (clkdiv > 255) {
+ dev_warn(&mmc->class_dev,
+ "clock %u too slow; using %lu\n",
+ clock_min, host->bus_hz / (2 * 256));
+ clkdiv = 255;
+ }
+ host->mode_reg = ATMCI_MR_CLKDIV(clkdiv);
}
- host->mode_reg = ATMCI_MR_CLKDIV(clkdiv);
-
/*
* WRPROOF and RDPROOF prevent overruns/underruns by
* stopping the clock when the FIFO is full/empty.
@@ -2000,37 +2012,35 @@ static void __init atmci_get_cap(struct atmel_mci *host)
"version: 0x%x\n", version);
host->caps.has_dma = 0;
- host->caps.has_pdc = 0;
+ host->caps.has_pdc = 1;
host->caps.has_cfg_reg = 0;
host->caps.has_cstor_reg = 0;
host->caps.has_highspeed = 0;
host->caps.has_rwproof = 0;
+ host->caps.has_odd_clk_div = 0;
/* keep only major version number */
switch (version & 0xf00) {
- case 0x100:
- host->caps.has_pdc = 1;
- break;
- case 0x200:
- host->caps.has_pdc = 1;
- host->caps.has_rwproof = 1;
- break;
- case 0x300:
- case 0x400:
case 0x500:
+ host->caps.has_odd_clk_div = 1;
+ case 0x400:
+ case 0x300:
#ifdef CONFIG_AT_HDMAC
host->caps.has_dma = 1;
#else
- host->caps.has_dma = 0;
dev_info(&host->pdev->dev,
"has dma capability but dma engine is not selected, then use pio\n");
#endif
+ host->caps.has_pdc = 0;
host->caps.has_cfg_reg = 1;
host->caps.has_cstor_reg = 1;
host->caps.has_highspeed = 1;
+ case 0x200:
host->caps.has_rwproof = 1;
+ case 0x100:
break;
default:
+ host->caps.has_pdc = 0;
dev_warn(&host->pdev->dev,
"Unmanaged mci version, set minimum capabilities\n");
break;
--
1.7.5.4
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