[U-Boot] [PATCH 2/2] fsl: esdhc: support driver model

[Peng Fan]

Support Driver Model for fsl esdhc driver.

In order to minimize the change, reuse the fsl_esdhc_initialize function.
This new way is to fill an fsl_esdhc_cfg struture and pass it
to fsl_esdhc_initialize, just like the code in different board codes.

Introduce a 'struct mmc *mmc' entry in fsl_esdhc_cfg structure,
otherwise fsl_esdhc_initialize may need to be restructured which will
cause lots changes for board code.

Since clk driver is not implemented, use mxc_get_clock here to
fill cfg->sdhc_clk. Anyway we can utilize the pinctrl imx driver
now, except the SPL part, we can drop the pinmux settings from
board file for mmc.

There are so many "ifdef" in the file, maybe we can use driver data
or quirks to cover these. But to minimize changes for this patch,
these are not included. Later we can try to discard the nasty
ifdef.

Has been tested on i.MX6UL 9x9 EVK board:
"
=>dm tree
....
 simple_bus  [ + ]    |   `-- aips-bus at 02100000
  mmc        [ + ]    |       |-- usdhc at 02190000
  mmc        [ + ]    |       |-- usdhc at 02194000
....
=> mmc list
FSL_SDHC: 0 (SD)
FSL_SDHC: 1 (SD)
"

Signed-off-by: Peng Fan <van.freenix at gmail.com>
Cc: York Sun <york.sun at nxp.com>
Cc: Yangbo Lu <yangbo.lu at nxp.com>
Cc: Hector Palacios <hector.palacios at digi.com>
Cc: Eric Nelson <eric at nelint.com>
Cc: Stefano Babic <sbabic at denx.de>
Cc: Fabio Estevam <fabio.estevam at nxp.com>
Cc: Pantelis Antoniou <panto at antoniou-consulting.com>
Cc: Simon Glass <sjg at chromium.org>
---
 drivers/mmc/fsl_esdhc.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/fsl_esdhc.h     |  1 +
 2 files changed, 82 insertions(+)

diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index ea5f4bf..1bd2174 100644
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -20,6 +20,8 @@
 #include <fsl_esdhc.h>
 #include <fdt_support.h>
 #include <asm/io.h>
+#include <dm.h>
+#include <asm/arch/clock.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -739,6 +741,8 @@ int fsl_esdhc_initialize(bd_t *bis, struct fsl_esdhc_cfg *cfg)
 	if (mmc == NULL)
 		return -1;
 
+	cfg->mmc = mmc;
+
 	return 0;
 }
 
@@ -819,3 +823,80 @@ void fdt_fixup_esdhc(void *blob, bd_t *bd)
 			   4 + 1, 1);
 }
 #endif
+
+#ifdef CONFIG_DM_MMC
+static int fsl_esdhc_probe(struct udevice *dev)
+{
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct fsl_esdhc_cfg *cfg = dev_get_priv(dev);
+	const void *fdt = gd->fdt_blob;
+	fdt_addr_t addr;
+	unsigned int val;
+	int node = dev->of_offset;
+	int ret;
+
+	addr = dev_get_addr(dev);
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	cfg->esdhc_base = (phys_addr_t)addr;
+
+	val = fdtdec_get_int(fdt, node, "bus-width", -1);
+	if (val == 8)
+		cfg->max_bus_width = 8;
+	else if (val == 4)
+		cfg->max_bus_width = 4;
+	else
+		cfg->max_bus_width = 1;
+
+	/*
+	 * TODO:
+	 * Because lack of clk driver, if SDHC clk is not enabled,
+	 * need to enable it first before this driver is invoked.
+	 *
+	 * we use MXC_ESDHC_CLK to get clk freq.
+	 * If one would like to make this function work,
+	 * the aliases should be provided in dts as this:
+	 *
+	 *  aliases {
+	 *	mmc0 = &usdhc1;
+	 *	mmc1 = &usdhc2;
+	 *	mmc2 = &usdhc3;
+	 *	mmc3 = &usdhc4;
+	 *	};
+	 * Then if your board only supports mmc2 and mmc3, but we can
+	 * correctly get the seq as 2 and 3, then let mxc_get_clock
+	 * work as expected.
+	 */
+	cfg->sdhc_clk = mxc_get_clock(MXC_ESDHC_CLK + dev->seq);
+	if (cfg->sdhc_clk <= 0) {
+		dev_err(dev, "Unable to get clk for %s\n", dev->name);
+		return -EINVAL;
+	}
+
+	ret = fsl_esdhc_initialize(NULL, cfg);
+	if (ret)
+		return ret;
+
+	upriv->mmc = cfg->mmc;
+
+	return 0;
+}
+
+static const struct udevice_id fsl_esdhc_ids[] = {
+	{ .compatible = "fsl,imx6ul-usdhc", },
+	{ .compatible = "fsl,imx6sx-usdhc", },
+	{ .compatible = "fsl,imx6sl-usdhc", },
+	{ .compatible = "fsl,imx6q-usdhc", },
+	{ .compatible = "fsl,imx7d-usdhc", },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(fsl_esdhc) = {
+	.name	= "fsl_esdhc_mmc",
+	.id	= UCLASS_MMC,
+	.of_match = fsl_esdhc_ids,
+	.probe	= fsl_esdhc_probe,
+	.priv_auto_alloc_size = sizeof(struct fsl_esdhc_cfg),
+};
+#endif
diff --git a/include/fsl_esdhc.h b/include/fsl_esdhc.h
index fa760a5..e0d3265 100644
--- a/include/fsl_esdhc.h
+++ b/include/fsl_esdhc.h
@@ -172,6 +172,7 @@ struct fsl_esdhc_cfg {
 	u32	sdhc_clk;
 	u8	max_bus_width;
 	struct mmc_config cfg;
+	struct mmc *mmc;
 };
 
 /* Select the correct accessors depending on endianess */
-- 
2.6.2