diff options
| -rw-r--r-- | Documentation/devicetree/bindings/mmc/renesas,mmcif.txt | 3 | ||||
| -rw-r--r-- | drivers/mmc/host/sh_mmcif.c | 84 |
2 files changed, 78 insertions, 9 deletions
diff --git a/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt b/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt index 299081f94abd..d38942f6c5ae 100644 --- a/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt +++ b/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt @@ -18,6 +18,8 @@ Required properties: dma-names property. - dma-names: must contain "tx" for the transmit DMA channel and "rx" for the receive DMA channel. +- max-frequency: Maximum operating clock frequency, driver uses default clock + frequency if it is not set. Example: R8A7790 (R-Car H2) MMCIF0 @@ -29,4 +31,5 @@ Example: R8A7790 (R-Car H2) MMCIF0 clocks = <&mstp3_clks R8A7790_CLK_MMCIF0>; dmas = <&dmac0 0xd1>, <&dmac0 0xd2>; dma-names = "tx", "rx"; + max-frequency = <97500000>; }; diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c index e13c5f41fac4..5a1fdd405b1a 100644 --- a/drivers/mmc/host/sh_mmcif.c +++ b/drivers/mmc/host/sh_mmcif.c @@ -57,6 +57,7 @@ #include <linux/mmc/slot-gpio.h> #include <linux/mod_devicetable.h> #include <linux/mutex.h> +#include <linux/of_device.h> #include <linux/pagemap.h> #include <linux/platform_device.h> #include <linux/pm_qos.h> @@ -224,6 +225,9 @@ enum sh_mmcif_wait_for { MMCIF_WAIT_FOR_STOP, }; +/* + * difference for each SoC + */ struct sh_mmcif_host { struct mmc_host *mmc; struct mmc_request *mrq; @@ -248,6 +252,7 @@ struct sh_mmcif_host { bool ccs_enable; /* Command Completion Signal support */ bool clk_ctrl2_enable; struct mutex thread_lock; + u32 clkdiv_map; /* see CE_CLK_CTRL::CLKDIV */ /* DMA support */ struct dma_chan *chan_rx; @@ -492,19 +497,55 @@ static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk) struct sh_mmcif_plat_data *p = dev->platform_data; bool sup_pclk = p ? p->sup_pclk : false; unsigned int current_clk = clk_get_rate(host->clk); + unsigned int clkdiv; sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE); sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR); if (!clk) return; - if (sup_pclk && clk == current_clk) - sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_SUP_PCLK); - else - sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR & - ((fls(DIV_ROUND_UP(current_clk, - clk) - 1) - 1) << 16)); + if (host->clkdiv_map) { + unsigned int freq, best_freq, myclk, div, diff_min, diff; + int i; + + clkdiv = 0; + diff_min = ~0; + best_freq = 0; + for (i = 31; i >= 0; i--) { + if (!((1 << i) & host->clkdiv_map)) + continue; + + /* + * clk = parent_freq / div + * -> parent_freq = clk x div + */ + + div = 1 << (i + 1); + freq = clk_round_rate(host->clk, clk * div); + myclk = freq / div; + diff = (myclk > clk) ? myclk - clk : clk - myclk; + + if (diff <= diff_min) { + best_freq = freq; + clkdiv = i; + diff_min = diff; + } + } + + dev_dbg(dev, "clk %u/%u (%u, 0x%x)\n", + (best_freq / (1 << (clkdiv + 1))), clk, + best_freq, clkdiv); + + clk_set_rate(host->clk, best_freq); + clkdiv = clkdiv << 16; + } else if (sup_pclk && clk == current_clk) { + clkdiv = CLK_SUP_PCLK; + } else { + clkdiv = (fls(DIV_ROUND_UP(current_clk, clk) - 1) - 1) << 16; + } + + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR & clkdiv); sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE); } @@ -1000,10 +1041,35 @@ static void sh_mmcif_request(struct mmc_host *mmc, struct mmc_request *mrq) static void sh_mmcif_clk_setup(struct sh_mmcif_host *host) { - unsigned int clk = clk_get_rate(host->clk); + struct device *dev = sh_mmcif_host_to_dev(host); + + if (host->mmc->f_max) { + unsigned int f_max, f_min = 0, f_min_old; + + f_max = host->mmc->f_max; + for (f_min_old = f_max; f_min_old > 2;) { + f_min = clk_round_rate(host->clk, f_min_old / 2); + if (f_min == f_min_old) + break; + f_min_old = f_min; + } + + /* + * This driver assumes this SoC is R-Car Gen2 or later + */ + host->clkdiv_map = 0x3ff; + + host->mmc->f_max = f_max / (1 << ffs(host->clkdiv_map)); + host->mmc->f_min = f_min / (1 << fls(host->clkdiv_map)); + } else { + unsigned int clk = clk_get_rate(host->clk); + + host->mmc->f_max = clk / 2; + host->mmc->f_min = clk / 512; + } - host->mmc->f_max = clk / 2; - host->mmc->f_min = clk / 512; + dev_dbg(dev, "clk max/min = %d/%d\n", + host->mmc->f_max, host->mmc->f_min); } static void sh_mmcif_set_power(struct sh_mmcif_host *host, struct mmc_ios *ios) |