| 1 | /* |
|---|
| 2 | * SDHCI support for CNS3xxx SoC |
|---|
| 3 | * |
|---|
| 4 | * Copyright 2008 Cavium Networks |
|---|
| 5 | * Copyright 2010 MontaVista Software, LLC. |
|---|
| 6 | * |
|---|
| 7 | * Authors: Scott Shu |
|---|
| 8 | * Anton Vorontsov <avorontsov@mvista.com> |
|---|
| 9 | * |
|---|
| 10 | * This program is free software; you can redistribute it and/or modify |
|---|
| 11 | * it under the terms of the GNU General Public License version 2 as |
|---|
| 12 | * published by the Free Software Foundation. |
|---|
| 13 | */ |
|---|
| 14 | |
|---|
| 15 | #include <linux/delay.h> |
|---|
| 16 | #include <linux/device.h> |
|---|
| 17 | #include <linux/mmc/host.h> |
|---|
| 18 | #include <linux/mmc/sdhci-pltfm.h> |
|---|
| 19 | #include <mach/cns3xxx.h> |
|---|
| 20 | #include "sdhci.h" |
|---|
| 21 | #include "sdhci-pltfm.h" |
|---|
| 22 | |
|---|
| 23 | static unsigned int sdhci_cns3xxx_get_max_clk(struct sdhci_host *host) |
|---|
| 24 | { |
|---|
| 25 | return 150000000; |
|---|
| 26 | } |
|---|
| 27 | |
|---|
| 28 | static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int clock) |
|---|
| 29 | { |
|---|
| 30 | struct device *dev = mmc_dev(host->mmc); |
|---|
| 31 | int div = 1; |
|---|
| 32 | u16 clk; |
|---|
| 33 | unsigned long timeout; |
|---|
| 34 | |
|---|
| 35 | if (clock == host->clock) |
|---|
| 36 | return; |
|---|
| 37 | |
|---|
| 38 | sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL); |
|---|
| 39 | |
|---|
| 40 | if (clock == 0) |
|---|
| 41 | goto out; |
|---|
| 42 | |
|---|
| 43 | while (host->max_clk / div > clock) { |
|---|
| 44 | /* |
|---|
| 45 | * On CNS3xxx divider grows linearly up to 4, and then |
|---|
| 46 | * exponentially up to 256. |
|---|
| 47 | */ |
|---|
| 48 | if (div < 4) |
|---|
| 49 | div += 1; |
|---|
| 50 | else if (div < 256) |
|---|
| 51 | div *= 2; |
|---|
| 52 | else |
|---|
| 53 | break; |
|---|
| 54 | } |
|---|
| 55 | |
|---|
| 56 | dev_dbg(dev, "desired SD clock: %d, actual: %d\n", |
|---|
| 57 | clock, host->max_clk / div); |
|---|
| 58 | |
|---|
| 59 | /* Divide by 3 is special. */ |
|---|
| 60 | if (div != 3) |
|---|
| 61 | div >>= 1; |
|---|
| 62 | |
|---|
| 63 | clk = div << SDHCI_DIVIDER_SHIFT; |
|---|
| 64 | clk |= SDHCI_CLOCK_INT_EN; |
|---|
| 65 | sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); |
|---|
| 66 | |
|---|
| 67 | timeout = 20; |
|---|
| 68 | while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL)) |
|---|
| 69 | & SDHCI_CLOCK_INT_STABLE)) { |
|---|
| 70 | if (timeout == 0) { |
|---|
| 71 | dev_warn(dev, "clock is unstable"); |
|---|
| 72 | break; |
|---|
| 73 | } |
|---|
| 74 | timeout--; |
|---|
| 75 | mdelay(1); |
|---|
| 76 | } |
|---|
| 77 | |
|---|
| 78 | clk |= SDHCI_CLOCK_CARD_EN; |
|---|
| 79 | sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); |
|---|
| 80 | out: |
|---|
| 81 | host->clock = clock; |
|---|
| 82 | } |
|---|
| 83 | |
|---|
| 84 | static struct sdhci_ops sdhci_cns3xxx_ops = { |
|---|
| 85 | .get_max_clock = sdhci_cns3xxx_get_max_clk, |
|---|
| 86 | .set_clock = sdhci_cns3xxx_set_clock, |
|---|
| 87 | }; |
|---|
| 88 | |
|---|
| 89 | struct sdhci_pltfm_data sdhci_cns3xxx_pdata = { |
|---|
| 90 | .ops = &sdhci_cns3xxx_ops, |
|---|
| 91 | .quirks = SDHCI_QUIRK_BROKEN_DMA | |
|---|
| 92 | SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK | |
|---|
| 93 | //SDHCI_QUIRK_INVERTED_WRITE_PROTECT | |
|---|
| 94 | SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN | |
|---|
| 95 | SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | |
|---|
| 96 | SDHCI_QUIRK_NONSTANDARD_CLOCK | |
|---|
| 97 | SDHCI_QUIRK_BROKEN_CARD_DETECTION, |
|---|
| 98 | }; |
|---|
