[PATCH] ARM: mxs: Use soc bus infrastructure
Shawn Guo
shawn.guo at linaro.org
Mon Jun 3 23:53:58 EDT 2013
On Mon, Jun 03, 2013 at 07:52:24PM -0300, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam at freescale.com>
>
> Using the soc bus infrastructure is helpful for reporting several SoC related
> information such as: family, machine, SoC name and SoC revision.
>
> $ cat /sys/bus/soc/devices/soc0/family
> Freescale MXS Family
>
> $ cat /sys/bus/soc/devices/soc0/machine
> Freescale i.MX28 Evaluation Kit
>
> $ cat /sys/bus/soc/devices/soc0/soc_id
> i.MX28
>
> $ cat /sys/bus/soc/devices/soc0/revision
> TO1.2
>
> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> ---
> arch/arm/mach-mxs/Kconfig | 1 +
> arch/arm/mach-mxs/mach-mxs.c | 117 ++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 117 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig
> index 4dc2fbb..59c30ef 100644
> --- a/arch/arm/mach-mxs/Kconfig
> +++ b/arch/arm/mach-mxs/Kconfig
> @@ -25,6 +25,7 @@ config ARCH_MXS
> select GENERIC_CLOCKEVENTS
> select HAVE_CLK_PREPARE
> select PINCTRL
> + select SOC_BUS
> select SOC_IMX23
> select SOC_IMX28
> select STMP_DEVICE
> diff --git a/arch/arm/mach-mxs/mach-mxs.c b/arch/arm/mach-mxs/mach-mxs.c
> index bd225e9..bc72393 100644
> --- a/arch/arm/mach-mxs/mach-mxs.c
> +++ b/arch/arm/mach-mxs/mach-mxs.c
> @@ -25,6 +25,7 @@
> #include <linux/of_platform.h>
> #include <linux/phy.h>
> #include <linux/pinctrl/consumer.h>
> +#include <linux/sys_soc.h>
> #include <asm/mach/arch.h>
> #include <asm/mach/map.h>
> #include <asm/mach/time.h>
> @@ -38,12 +39,27 @@
> #define MXS_DIGCTL_SAIF_CLKMUX_EXTMSTR0 0x2
> #define MXS_DIGCTL_SAIF_CLKMUX_EXTMSTR1 0x3
>
> +#define HW_DIGCTL_CHIPID 0x310
> +#define HW_DIGCTL_CHIPID_MASK (0xffff << 16)
> +#define HW_DIGCTL_REV_MASK 0xff
> +#define HW_DIGCTL_CHIPID_MX23 (0x3780 << 16)
> +#define HW_DIGCTL_CHIPID_MX28 (0x2800 << 16)
> +
> +#define MXS_CHIP_REVISION_1_0 0x10
> +#define MXS_CHIP_REVISION_1_1 0x11
> +#define MXS_CHIP_REVISION_1_2 0x12
> +#define MXS_CHIP_REVISION_1_3 0x13
> +#define MXS_CHIP_REVISION_1_4 0x14
> +#define MXS_CHIP_REV_UNKNOWN 0xff
> +
> #define MXS_GPIO_NR(bank, nr) ((bank) * 32 + (nr))
>
> #define MXS_SET_ADDR 0x4
> #define MXS_CLR_ADDR 0x8
> #define MXS_TOG_ADDR 0xc
>
> +static void __iomem *digctl_base;
> +
Rather than defining a static base address for reading the same register
multiple times, I would suggest we define static variables to hold id
and revision with accessing register only once. In that case, the
digctl_base can be a local variable in function and could be unmapped
after we're done with it.
> static inline void __mxs_setl(u32 mask, void __iomem *reg)
> {
> __raw_writel(mask, reg + MXS_SET_ADDR);
> @@ -361,8 +377,107 @@ static void __init cfa10037_init(void)
> update_fec_mac_prop(OUI_CRYSTALFONTZ);
> }
>
> +static const char __init *mxs_get_soc_id(void)
> +{
> + u32 socid;
> + struct device_node *np;
> +
> + np = of_find_compatible_node(NULL, NULL, "fsl,imx28-digctl");
It will fail to find the node when running on i.MX23. It seems we need
to change the digctl node in imx28 device tree as below, and then use
"fsl,imx23-digctl" to find the node.
compatible = "fsl,imx28-digctl", "fsl,imx23-digctl"
> + digctl_base = of_iomap(np, 0);
> + WARN_ON(!digctl_base);
> +
> + socid = readl(digctl_base + HW_DIGCTL_CHIPID) & HW_DIGCTL_CHIPID_MASK;
> + switch (socid) {
> + case HW_DIGCTL_CHIPID_MX23:
> + return "i.MX23";
> + case HW_DIGCTL_CHIPID_MX28:
> + return "i.MX28";
> + default:
> + return "unknown";
> + }
> +}
> +
> +static int __init mxs_get_cpu_rev(void)
> +{
> + u32 socid, rev;
> +
> + socid = readl(digctl_base + HW_DIGCTL_CHIPID) & HW_DIGCTL_CHIPID_MASK;
> + rev = readl(digctl_base + HW_DIGCTL_CHIPID) & HW_DIGCTL_REV_MASK;
> +
> + switch (socid) {
> + case HW_DIGCTL_CHIPID_MX23:
> + switch (rev) {
> + case 0x0:
> + return MXS_CHIP_REVISION_1_0;
> + case 0x1:
> + return MXS_CHIP_REVISION_1_1;
> + case 0x2:
> + return MXS_CHIP_REVISION_1_2;
> + case 0x3:
> + return MXS_CHIP_REVISION_1_3;
> + case 0x4:
> + return MXS_CHIP_REVISION_1_4;
> + default:
> + return MXS_CHIP_REV_UNKNOWN;
> + }
> + case HW_DIGCTL_CHIPID_MX28:
> + switch (rev) {
> + case 0x0:
> + return MXS_CHIP_REVISION_1_1;
> + case 0x1:
> + return MXS_CHIP_REVISION_1_2;
> + default:
> + return MXS_CHIP_REV_UNKNOWN;
> + }
> + default:
> + return MXS_CHIP_REV_UNKNOWN;
> + }
I do not understand why we need to set up all these mapping at all. I
think all we need is reporting the revision in the format you gave
below.
kasprintf(GFP_KERNEL, "TO%d.%d", (rev >> 4) & 0xf, rev & 0xf);
> +}
> +
> +static const char __init *mxs_get_revision(void)
> +{
> + u32 rev = mxs_get_cpu_rev();
> +
> + if (rev != MXS_CHIP_REV_UNKNOWN)
> + return kasprintf(GFP_KERNEL, "TO%d.%d", (rev >> 4) & 0xf,
> + rev & 0xf);
> +
> + else
> + return kasprintf(GFP_KERNEL, "%s", "Unknown");
> +}
> +
> static void __init mxs_machine_init(void)
> {
> + struct device_node *root;
> + struct device *parent;
> + struct soc_device *soc_dev;
> + struct soc_device_attribute *soc_dev_attr;
> + int ret;
> +
> + root = of_find_node_by_path("/");
> + if (!root)
> + return;
I do not think the check is needed. We will never get here if there is
no device tree root node.
> +
> + soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
> + if (!soc_dev_attr)
> + return;
> +
> + ret = of_property_read_string(root, "model", &soc_dev_attr->machine);
> + if (ret)
> + return;
> +
> + soc_dev_attr->family = "Freescale MXS Family";
> + soc_dev_attr->soc_id = mxs_get_soc_id();
> + soc_dev_attr->revision = mxs_get_revision();
> +
> + soc_dev = soc_device_register(soc_dev_attr);
> + if (IS_ERR(soc_dev)) {
soc_dev_attr->revision should be freed.
Shawn
> + kfree(soc_dev_attr);
> + return;
> + }
> +
> + parent = soc_device_to_device(soc_dev);
> +
> if (of_machine_is_compatible("fsl,imx28-evk"))
> imx28_evk_init();
> else if (of_machine_is_compatible("bluegiga,apx4devkit"))
> @@ -373,7 +488,7 @@ static void __init mxs_machine_init(void)
> cfa10049_init();
>
> of_platform_populate(NULL, of_default_bus_match_table,
> - mxs_auxdata_lookup, NULL);
> + mxs_auxdata_lookup, parent);
>
> if (of_machine_is_compatible("karo,tx28"))
> tx28_post_init();
> --
> 1.8.1.2
>
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