diff options
| -rw-r--r-- | drivers/mailbox/pcc.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index ae4b7a4b3531..deaea9d423a7 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -52,6 +52,7 @@ #include <linux/init.h> #include <linux/interrupt.h> #include <linux/list.h> +#include <linux/log2.h> #include <linux/platform_device.h> #include <linux/mailbox_controller.h> #include <linux/mailbox_client.h> @@ -65,6 +66,23 @@ static struct mbox_chan *pcc_mbox_channels; /** + * struct pcc_chan_reg - PCC register bundle + * + * @vaddr: cached virtual address for this register + * @gas: pointer to the generic address structure for this register + * @preserve_mask: bitmask to preserve when writing to this register + * @set_mask: bitmask to set when writing to this register + * @status_mask: bitmask to determine and/or update the status for this register + */ +struct pcc_chan_reg { + void __iomem *vaddr; + struct acpi_generic_address *gas; + u64 preserve_mask; + u64 set_mask; + u64 status_mask; +}; + +/** * struct pcc_chan_info - PCC channel specific information * * @chan: PCC channel information with Shared Memory Region info @@ -144,6 +162,53 @@ static int write_register(void __iomem *vaddr, u64 val, unsigned int bit_width) return ret_val; } +static int pcc_chan_reg_read(struct pcc_chan_reg *reg, u64 *val) +{ + int ret = 0; + + if (!reg->gas) { + *val = 0; + return 0; + } + + if (reg->vaddr) + ret = read_register(reg->vaddr, val, reg->gas->bit_width); + else + ret = acpi_read(val, reg->gas); + + return ret; +} + +static int pcc_chan_reg_write(struct pcc_chan_reg *reg, u64 val) +{ + int ret = 0; + + if (!reg->gas) + return 0; + + if (reg->vaddr) + ret = write_register(reg->vaddr, val, reg->gas->bit_width); + else + ret = acpi_write(val, reg->gas); + + return ret; +} + +static int pcc_chan_reg_read_modify_write(struct pcc_chan_reg *reg) +{ + int ret = 0; + u64 val; + + ret = pcc_chan_reg_read(reg, &val); + if (ret) + return ret; + + val &= reg->preserve_mask; + val |= reg->set_mask; + + return pcc_chan_reg_write(reg, val); +} + /** * pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number * @interrupt: GSI number. @@ -379,6 +444,31 @@ static int parse_pcc_subspace(union acpi_subtable_headers *header, return -EINVAL; } +static int +pcc_chan_reg_init(struct pcc_chan_reg *reg, struct acpi_generic_address *gas, + u64 preserve_mask, u64 set_mask, u64 status_mask, char *name) +{ + if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { + if (!(gas->bit_width >= 8 && gas->bit_width <= 64 && + is_power_of_2(gas->bit_width))) { + pr_err("Error: Cannot access register of %u bit width", + gas->bit_width); + return -EFAULT; + } + + reg->vaddr = acpi_os_ioremap(gas->address, gas->bit_width / 8); + if (!reg->vaddr) { + pr_err("Failed to ioremap PCC %s register\n", name); + return -ENOMEM; + } + } + reg->gas = gas; + reg->preserve_mask = preserve_mask; + reg->set_mask = set_mask; + reg->status_mask = status_mask; + return 0; +} + /** * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register * |