From: Kuninori Morimoto <[email protected]> MMCIF IP on R-Car series has parent clock which can be set several rate, and it was not implemented on old SH-Mobile series (= SH-Mobile series parent clock was fixed rate) R-Car series MMCIF can use more high speed access if it setup parent clock. This patch adds parent clock setup method, and r8a7790/r8a7791 can use it.
Signed-off-by: Kuninori Morimoto <[email protected]> Tested-by: Keita Kobayashi <[email protected]> --- v3 -> v4 - add new clk-range on DT - use clk_round_rate() for parent_clk - struct sh_mmcif_ver instead of sh_mmcif_parent_clk .../devicetree/bindings/mmc/renesas,mmcif.txt | 3 + drivers/mmc/host/sh_mmcif.c | 89 +++++++++++++++++++++- 2 files changed, 90 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt b/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt index 299081f..eb50f4e 100644 --- a/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt +++ b/Documentation/devicetree/bindings/mmc/renesas,mmcif.txt @@ -14,6 +14,8 @@ Required properties: - clocks: reference to the functional clock +- clk-range: parent clock range + - dmas: reference to the DMA channels, one per channel name listed in the dma-names property. - dma-names: must contain "tx" for the transmit DMA channel and "rx" for the @@ -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"; + clk-range = <12187500 97500000>; }; diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c index d2f1158..437aa3c 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 +225,13 @@ enum mmcif_wait_for { MMCIF_WAIT_FOR_STOP, }; +/* + * difference for each SoC + */ +struct sh_mmcif_ver { + u32 clkdiv_map; /* see CE_CLK_CTRL::CLKDIV */ +}; + struct sh_mmcif_host { struct mmc_host *mmc; struct mmc_request *mrq; @@ -248,6 +256,7 @@ struct sh_mmcif_host { bool ccs_enable; /* Command Completion Signal support */ bool clk_ctrl2_enable; struct mutex thread_lock; + const struct sh_mmcif_ver *ver; /* DMA support */ struct dma_chan *chan_rx; @@ -256,8 +265,14 @@ struct sh_mmcif_host { bool dma_active; }; +static const struct sh_mmcif_ver sh_mmcif_gen2 = { + .clkdiv_map = 0x3ff, +}; + static const struct of_device_id mmcif_of_match[] = { { .compatible = "renesas,sh-mmcif" }, + { .compatible = "renesas,mmcif-r8a7790", .data = &sh_mmcif_gen2}, + { .compatible = "renesas,mmcif-r8a7791", .data = &sh_mmcif_gen2}, { } }; MODULE_DEVICE_TABLE(of, mmcif_of_match); @@ -490,12 +505,50 @@ static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk) if (!clk) return; - if (sup_pclk && clk == current_clk) + + if (host->ver) { + const struct sh_mmcif_ver *ver = host->ver; + unsigned int freq, best_freq, myclk, clkdiv, div, diff_min, diff; + int i; + + clkdiv = 0; + diff_min = ~0; + best_freq = 0; + for (i = fls(ver->clkdiv_map); i >= 0; i--) { + if (!((1 << i) & ver->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(&host->pd->dev, "clk %u/%u (%u, 0x%x)\n", + (best_freq / (1 << (clkdiv + 1))), clk, + best_freq, clkdiv); + + clk_set_rate(host->clk, best_freq); + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, + CLK_CLEAR & (clkdiv << 16)); + } else if (sup_pclk && clk == current_clk) { sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_SUP_PCLK); - else + } else { sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR & ((fls(DIV_ROUND_UP(current_clk, clk) - 1) - 1) << 16)); + } sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE); } @@ -980,10 +1033,42 @@ static void sh_mmcif_request(struct mmc_host *mmc, struct mmc_request *mrq) static void sh_mmcif_clk_setup(struct sh_mmcif_host *host) { + struct device *dev = &host->pd->dev; + const struct of_device_id *of_id = of_match_device(mmcif_of_match, dev); unsigned int clk = clk_get_rate(host->clk); + if (of_id) { + struct device_node *np = dev->of_node; + const struct sh_mmcif_ver *ver = of_id->data; + u32 range[2]; /* min/max */ + + if (!ver) + goto sh_mmcif_clk_setup_default; + + if (0 != of_property_read_u32_array(np, "clk-range", + range, ARRAY_SIZE(range))) + goto sh_mmcif_clk_setup_default; + + if (range[0] > range[1]) + goto sh_mmcif_clk_setup_default; + + host->mmc->f_min = range[0] / (1 << fls(ver->clkdiv_map)); + host->mmc->f_max = range[1] / (1 << ffs(ver->clkdiv_map)); + + dev_dbg(dev, "parent clk <%d - %d> (%d/%d)\n", + range[0], range[1], + host->mmc->f_max, host->mmc->f_min); + + host->ver = ver; + return; + } + +sh_mmcif_clk_setup_default: 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) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
