diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-of-aspeed.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-aspeed.c | 216 |
1 files changed, 208 insertions, 8 deletions
diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c index 4f008ba3280e..b1a14e7dda82 100644 --- a/drivers/mmc/host/sdhci-of-aspeed.c +++ b/drivers/mmc/host/sdhci-of-aspeed.c @@ -6,6 +6,7 @@ #include <linux/delay.h> #include <linux/device.h> #include <linux/io.h> +#include <linux/math64.h> #include <linux/mmc/host.h> #include <linux/module.h> #include <linux/of_address.h> @@ -16,9 +17,19 @@ #include "sdhci-pltfm.h" -#define ASPEED_SDC_INFO 0x00 -#define ASPEED_SDC_S1MMC8 BIT(25) -#define ASPEED_SDC_S0MMC8 BIT(24) +#define ASPEED_SDC_INFO 0x00 +#define ASPEED_SDC_S1_MMC8 BIT(25) +#define ASPEED_SDC_S0_MMC8 BIT(24) +#define ASPEED_SDC_PHASE 0xf4 +#define ASPEED_SDC_S1_PHASE_IN GENMASK(25, 21) +#define ASPEED_SDC_S0_PHASE_IN GENMASK(20, 16) +#define ASPEED_SDC_S1_PHASE_OUT GENMASK(15, 11) +#define ASPEED_SDC_S1_PHASE_IN_EN BIT(10) +#define ASPEED_SDC_S1_PHASE_OUT_EN GENMASK(9, 8) +#define ASPEED_SDC_S0_PHASE_OUT GENMASK(7, 3) +#define ASPEED_SDC_S0_PHASE_IN_EN BIT(2) +#define ASPEED_SDC_S0_PHASE_OUT_EN GENMASK(1, 0) +#define ASPEED_SDC_PHASE_MAX 31 struct aspeed_sdc { struct clk *clk; @@ -28,9 +39,36 @@ struct aspeed_sdc { void __iomem *regs; }; +struct aspeed_sdhci_tap_param { + bool valid; + +#define ASPEED_SDHCI_TAP_PARAM_INVERT_CLK BIT(4) + u8 in; + u8 out; +}; + +struct aspeed_sdhci_tap_desc { + u32 tap_mask; + u32 enable_mask; + u8 enable_value; +}; + +struct aspeed_sdhci_phase_desc { + struct aspeed_sdhci_tap_desc in; + struct aspeed_sdhci_tap_desc out; +}; + +struct aspeed_sdhci_pdata { + const struct aspeed_sdhci_phase_desc *phase_desc; + size_t nr_phase_descs; +}; + struct aspeed_sdhci { + const struct aspeed_sdhci_pdata *pdata; struct aspeed_sdc *parent; u32 width_mask; + struct mmc_clk_phase_map phase_map; + const struct aspeed_sdhci_phase_desc *phase_desc; }; static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc, @@ -50,10 +88,118 @@ static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc, spin_unlock(&sdc->lock); } +static u32 +aspeed_sdc_set_phase_tap(const struct aspeed_sdhci_tap_desc *desc, + u8 tap, bool enable, u32 reg) +{ + reg &= ~(desc->enable_mask | desc->tap_mask); + if (enable) { + reg |= tap << __ffs(desc->tap_mask); + reg |= desc->enable_value << __ffs(desc->enable_mask); + } + + return reg; +} + +static void +aspeed_sdc_set_phase_taps(struct aspeed_sdc *sdc, + const struct aspeed_sdhci_phase_desc *desc, + const struct aspeed_sdhci_tap_param *taps) +{ + u32 reg; + + spin_lock(&sdc->lock); + reg = readl(sdc->regs + ASPEED_SDC_PHASE); + + reg = aspeed_sdc_set_phase_tap(&desc->in, taps->in, taps->valid, reg); + reg = aspeed_sdc_set_phase_tap(&desc->out, taps->out, taps->valid, reg); + + writel(reg, sdc->regs + ASPEED_SDC_PHASE); + spin_unlock(&sdc->lock); +} + +#define PICOSECONDS_PER_SECOND 1000000000000ULL +#define ASPEED_SDHCI_NR_TAPS 15 +/* Measured value with *handwave* environmentals and static loading */ +#define ASPEED_SDHCI_MAX_TAP_DELAY_PS 1253 +static int aspeed_sdhci_phase_to_tap(struct device *dev, unsigned long rate_hz, + int phase_deg) +{ + u64 phase_period_ps; + u64 prop_delay_ps; + u64 clk_period_ps; + unsigned int tap; + u8 inverted; + + phase_deg %= 360; + + if (phase_deg >= 180) { + inverted = ASPEED_SDHCI_TAP_PARAM_INVERT_CLK; + phase_deg -= 180; + dev_dbg(dev, + "Inverting clock to reduce phase correction from %d to %d degrees\n", + phase_deg + 180, phase_deg); + } else { + inverted = 0; + } + + prop_delay_ps = ASPEED_SDHCI_MAX_TAP_DELAY_PS / ASPEED_SDHCI_NR_TAPS; + clk_period_ps = div_u64(PICOSECONDS_PER_SECOND, (u64)rate_hz); + phase_period_ps = div_u64((u64)phase_deg * clk_period_ps, 360ULL); + + tap = div_u64(phase_period_ps, prop_delay_ps); + if (tap > ASPEED_SDHCI_NR_TAPS) { + dev_warn(dev, + "Requested out of range phase tap %d for %d degrees of phase compensation at %luHz, clamping to tap %d\n", + tap, phase_deg, rate_hz, ASPEED_SDHCI_NR_TAPS); + tap = ASPEED_SDHCI_NR_TAPS; + } + + return inverted | tap; +} + +static void +aspeed_sdhci_phases_to_taps(struct device *dev, unsigned long rate, + const struct mmc_clk_phase *phases, + struct aspeed_sdhci_tap_param *taps) +{ + taps->valid = phases->valid; + + if (!phases->valid) + return; + + taps->in = aspeed_sdhci_phase_to_tap(dev, rate, phases->in_deg); + taps->out = aspeed_sdhci_phase_to_tap(dev, rate, phases->out_deg); +} + +static void +aspeed_sdhci_configure_phase(struct sdhci_host *host, unsigned long rate) +{ + struct aspeed_sdhci_tap_param _taps = {0}, *taps = &_taps; + struct mmc_clk_phase *params; + struct aspeed_sdhci *sdhci; + struct device *dev; + + dev = host->mmc->parent; + sdhci = sdhci_pltfm_priv(sdhci_priv(host)); + + if (!sdhci->phase_desc) + return; + + params = &sdhci->phase_map.phase[host->timing]; + aspeed_sdhci_phases_to_taps(dev, rate, params, taps); + aspeed_sdc_set_phase_taps(sdhci->parent, sdhci->phase_desc, taps); + dev_dbg(dev, + "Using taps [%d, %d] for [%d, %d] degrees of phase correction at %luHz (%d)\n", + taps->in & ASPEED_SDHCI_NR_TAPS, + taps->out & ASPEED_SDHCI_NR_TAPS, + params->in_deg, params->out_deg, rate, host->timing); +} + static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock) { struct sdhci_pltfm_host *pltfm_host; - unsigned long parent; + unsigned long parent, bus; int div; u16 clk; @@ -69,13 +215,17 @@ static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock) clock = host->max_clk; for (div = 2; div < 256; div *= 2) { - if ((parent / div) <= clock) + bus = parent / div; + if (bus <= clock) break; } + div >>= 1; clk = div << SDHCI_DIVIDER_SHIFT; + aspeed_sdhci_configure_phase(host, bus); + sdhci_enable_clk(host, clk); } @@ -157,6 +307,7 @@ static inline int aspeed_sdhci_calculate_slot(struct aspeed_sdhci *dev, static int aspeed_sdhci_probe(struct platform_device *pdev) { + const struct aspeed_sdhci_pdata *aspeed_pdata; struct sdhci_pltfm_host *pltfm_host; struct aspeed_sdhci *dev; struct sdhci_host *host; @@ -164,12 +315,15 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) int slot; int ret; + aspeed_pdata = of_device_get_match_data(&pdev->dev); + host = sdhci_pltfm_init(pdev, &aspeed_sdhci_pdata, sizeof(*dev)); if (IS_ERR(host)) return PTR_ERR(host); pltfm_host = sdhci_priv(host); dev = sdhci_pltfm_priv(pltfm_host); + dev->pdata = aspeed_pdata; dev->parent = dev_get_drvdata(pdev->dev.parent); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -180,8 +334,17 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) else if (slot >= 2) return -EINVAL; - dev_info(&pdev->dev, "Configuring for slot %d\n", slot); - dev->width_mask = !slot ? ASPEED_SDC_S0MMC8 : ASPEED_SDC_S1MMC8; + if (dev->pdata && slot < dev->pdata->nr_phase_descs) { + dev->phase_desc = &dev->pdata->phase_desc[slot]; + } else { + dev_info(&pdev->dev, + "Phase control not supported for slot %d\n", slot); + dev->phase_desc = NULL; + } + + dev->width_mask = !slot ? ASPEED_SDC_S0_MMC8 : ASPEED_SDC_S1_MMC8; + + dev_info(&pdev->dev, "Configured for slot %d\n", slot); sdhci_get_of_property(pdev); @@ -199,6 +362,9 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) if (ret) goto err_sdhci_add; + if (dev->phase_desc) + mmc_of_parse_clk_phase(host->mmc, &dev->phase_map); + ret = sdhci_add_host(host); if (ret) goto err_sdhci_add; @@ -230,10 +396,44 @@ static int aspeed_sdhci_remove(struct platform_device *pdev) return 0; } +static const struct aspeed_sdhci_phase_desc ast2600_sdhci_phase[] = { + /* SDHCI/Slot 0 */ + [0] = { + .in = { + .tap_mask = ASPEED_SDC_S0_PHASE_IN, + .enable_mask = ASPEED_SDC_S0_PHASE_IN_EN, + .enable_value = 1, + }, + .out = { + .tap_mask = ASPEED_SDC_S0_PHASE_OUT, + .enable_mask = ASPEED_SDC_S0_PHASE_OUT_EN, + .enable_value = 3, + }, + }, + /* SDHCI/Slot 1 */ + [1] = { + .in = { + .tap_mask = ASPEED_SDC_S1_PHASE_IN, + .enable_mask = ASPEED_SDC_S1_PHASE_IN_EN, + .enable_value = 1, + }, + .out = { + .tap_mask = ASPEED_SDC_S1_PHASE_OUT, + .enable_mask = ASPEED_SDC_S1_PHASE_OUT_EN, + .enable_value = 3, + }, + }, +}; + +static const struct aspeed_sdhci_pdata ast2600_sdhci_pdata = { + .phase_desc = ast2600_sdhci_phase, + .nr_phase_descs = ARRAY_SIZE(ast2600_sdhci_phase), +}; + static const struct of_device_id aspeed_sdhci_of_match[] = { { .compatible = "aspeed,ast2400-sdhci", }, { .compatible = "aspeed,ast2500-sdhci", }, - { .compatible = "aspeed,ast2600-sdhci", }, + { .compatible = "aspeed,ast2600-sdhci", .data = &ast2600_sdhci_pdata, }, { } }; |