From faf8180b20882b52145b96d6d4ed082d41908f90 Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Wed, 21 Mar 2012 16:41:23 +0100 Subject: [PATCH] mmc: atmel-mci: add support for odd clock dividers Add an odd clock divider capability available from v5xx. It also involves changing the clock divider calculation, and changing the switch-case statement to use top-down fallthrough. Signed-off-by: Ludovic Desroches Acked-by: Nicolas Ferre Signed-off-by: Chris Ball --- 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 000b3ad0f5ca..787aba1682bb 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 c56edc4a8e26..e94476beca18 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -77,6 +77,7 @@ struct atmel_mci_caps { bool has_cstor_reg; bool has_highspeed; bool has_rwproof; + bool has_odd_clk_div; }; struct atmel_mci_dma { @@ -1134,16 +1135,27 @@ 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. @@ -2014,37 +2026,35 @@ 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; -- 2.20.1