From: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
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 setups parent clock. This patch adds parent clock setup
method. It will be used if DT has "max-frequency", and then, this driver
assumes it is booted on R-Car Gen2 or later SoC. Because SH-Mobile series
(which doesn't boot from DT) and R-Car series (which boots from DT) have
different divider.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
Tested-by: Keita Kobayashi <keita.kobayashi.ym@xxxxxxxxxxx>
---
v5 -> v6
- it uses max-frequency
- don't add new compatible string
.../devicetree/bindings/mmc/renesas,mmcif.txt | 3 +
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 299081f..d38942f 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 e13c5f41..554fa9d 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, 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)
--
1.9.1
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