diff options
Diffstat (limited to 'drivers/nvmem/sunxi_sid.c')
| -rw-r--r-- | drivers/nvmem/sunxi_sid.c | 89 |
1 files changed, 85 insertions, 4 deletions
diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c index 1567ccca8de3..0d6648be93b8 100644 --- a/drivers/nvmem/sunxi_sid.c +++ b/drivers/nvmem/sunxi_sid.c @@ -17,13 +17,24 @@ #include <linux/device.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/module.h> #include <linux/nvmem-provider.h> #include <linux/of.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/random.h> +/* Registers and special values for doing register-based SID readout on H3 */ +#define SUN8I_SID_PRCTL 0x40 +#define SUN8I_SID_RDKEY 0x60 + +#define SUN8I_SID_OFFSET_MASK 0x1FF +#define SUN8I_SID_OFFSET_SHIFT 16 +#define SUN8I_SID_OP_LOCK (0xAC << 8) +#define SUN8I_SID_READ BIT(1) + static struct nvmem_config econfig = { .name = "sunxi-sid", .read_only = true, @@ -32,8 +43,15 @@ static struct nvmem_config econfig = { .owner = THIS_MODULE, }; +struct sunxi_sid_cfg { + u32 value_offset; + u32 size; + bool need_register_readout; +}; + struct sunxi_sid { void __iomem *base; + u32 value_offset; }; /* We read the entire key, due to a 32 bit read alignment requirement. Since we @@ -58,12 +76,36 @@ static int sunxi_sid_read(void *context, unsigned int offset, struct sunxi_sid *sid = context; u8 *buf = val; + /* Offset the read operation to the real position of SID */ + offset += sid->value_offset; + while (bytes--) *buf++ = sunxi_sid_read_byte(sid, offset++); return 0; } +static int sun8i_sid_register_readout(const struct sunxi_sid *sid, + const unsigned int word) +{ + u32 reg_val; + int ret; + + /* Set word, lock access, and set read command */ + reg_val = (word & SUN8I_SID_OFFSET_MASK) + << SUN8I_SID_OFFSET_SHIFT; + reg_val |= SUN8I_SID_OP_LOCK | SUN8I_SID_READ; + writel(reg_val, sid->base + SUN8I_SID_PRCTL); + + ret = readl_poll_timeout(sid->base + SUN8I_SID_PRCTL, reg_val, + !(reg_val & SUN8I_SID_READ), 100, 250000); + if (ret) + return ret; + + writel(0, sid->base + SUN8I_SID_PRCTL); + return 0; +} + static int sunxi_sid_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -72,18 +114,42 @@ static int sunxi_sid_probe(struct platform_device *pdev) struct sunxi_sid *sid; int ret, i, size; char *randomness; + const struct sunxi_sid_cfg *cfg; sid = devm_kzalloc(dev, sizeof(*sid), GFP_KERNEL); if (!sid) return -ENOMEM; + cfg = of_device_get_match_data(dev); + if (!cfg) + return -EINVAL; + sid->value_offset = cfg->value_offset; + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); sid->base = devm_ioremap_resource(dev, res); if (IS_ERR(sid->base)) return PTR_ERR(sid->base); - size = resource_size(res) - 1; - econfig.size = resource_size(res); + size = cfg->size; + + if (cfg->need_register_readout) { + /* + * H3's SID controller have a bug that the value at 0x200 + * offset is not the correct value when the hardware is reseted. + * However, after doing a register-based read operation, the + * value become right. + * Do a full read operation here, but ignore its value + * (as it's more fast to read by direct MMIO value than + * with registers) + */ + for (i = 0; i < (size >> 2); i++) { + ret = sun8i_sid_register_readout(sid, i); + if (ret) + return ret; + } + } + + econfig.size = size; econfig.dev = dev; econfig.reg_read = sunxi_sid_read; econfig.priv = sid; @@ -119,9 +185,24 @@ static int sunxi_sid_remove(struct platform_device *pdev) return nvmem_unregister(nvmem); } +static const struct sunxi_sid_cfg sun4i_a10_cfg = { + .size = 0x10, +}; + +static const struct sunxi_sid_cfg sun7i_a20_cfg = { + .size = 0x200, +}; + +static const struct sunxi_sid_cfg sun8i_h3_cfg = { + .value_offset = 0x200, + .size = 0x100, + .need_register_readout = true, +}; + static const struct of_device_id sunxi_sid_of_match[] = { - { .compatible = "allwinner,sun4i-a10-sid" }, - { .compatible = "allwinner,sun7i-a20-sid" }, + { .compatible = "allwinner,sun4i-a10-sid", .data = &sun4i_a10_cfg }, + { .compatible = "allwinner,sun7i-a20-sid", .data = &sun7i_a20_cfg }, + { .compatible = "allwinner,sun8i-h3-sid", .data = &sun8i_h3_cfg }, {/* sentinel */}, }; MODULE_DEVICE_TABLE(of, sunxi_sid_of_match); |