diff options
Diffstat (limited to 'drivers/soc/bcm/brcmstb/biuctrl.c')
| -rw-r--r-- | drivers/soc/bcm/brcmstb/biuctrl.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/drivers/soc/bcm/brcmstb/biuctrl.c b/drivers/soc/bcm/brcmstb/biuctrl.c new file mode 100644 index 000000000..20b63bee5 --- /dev/null +++ b/drivers/soc/bcm/brcmstb/biuctrl.c @@ -0,0 +1,265 @@ +/* + * Broadcom STB SoCs Bus Unit Interface controls + * + * Copyright (C) 2015, Broadcom Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) "brcmstb: " KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/syscore_ops.h> +#include <linux/soc/brcmstb/brcmstb.h> + +#define CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK 0x70000000 +#define CPU_CREDIT_REG_MCPx_READ_CRED_MASK 0xf +#define CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK 0xf +#define CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(x) ((x) * 8) +#define CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(x) (((x) * 8) + 4) + +#define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(x) ((x) * 8) +#define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK 0xff + +#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK 0xf +#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK 0xf +#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT 4 +#define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE BIT(8) + +static void __iomem *cpubiuctrl_base; +static bool mcp_wr_pairing_en; +static const int *cpubiuctrl_regs; + +static inline u32 cbc_readl(int reg) +{ + int offset = cpubiuctrl_regs[reg]; + + if (offset == -1) + return (u32)-1; + + return readl_relaxed(cpubiuctrl_base + offset); +} + +static inline void cbc_writel(u32 val, int reg) +{ + int offset = cpubiuctrl_regs[reg]; + + if (offset == -1) + return; + + writel(val, cpubiuctrl_base + offset); +} + +enum cpubiuctrl_regs { + CPU_CREDIT_REG = 0, + CPU_MCP_FLOW_REG, + CPU_WRITEBACK_CTRL_REG +}; + +static const int b15_cpubiuctrl_regs[] = { + [CPU_CREDIT_REG] = 0x184, + [CPU_MCP_FLOW_REG] = -1, + [CPU_WRITEBACK_CTRL_REG] = -1, +}; + +/* Odd cases, e.g: 7260 */ +static const int b53_cpubiuctrl_no_wb_regs[] = { + [CPU_CREDIT_REG] = 0x0b0, + [CPU_MCP_FLOW_REG] = 0x0b4, + [CPU_WRITEBACK_CTRL_REG] = -1, +}; + +static const int b53_cpubiuctrl_regs[] = { + [CPU_CREDIT_REG] = 0x0b0, + [CPU_MCP_FLOW_REG] = 0x0b4, + [CPU_WRITEBACK_CTRL_REG] = 0x22c, +}; + +#define NUM_CPU_BIUCTRL_REGS 3 + +static int __init mcp_write_pairing_set(void) +{ + u32 creds = 0; + + if (!cpubiuctrl_base) + return -1; + + creds = cbc_readl(CPU_CREDIT_REG); + if (mcp_wr_pairing_en) { + pr_info("MCP: Enabling write pairing\n"); + cbc_writel(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK, + CPU_CREDIT_REG); + } else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) { + pr_info("MCP: Disabling write pairing\n"); + cbc_writel(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK, + CPU_CREDIT_REG); + } else { + pr_info("MCP: Write pairing already disabled\n"); + } + + return 0; +} + +static const u32 b53_mach_compat[] = { + 0x7268, + 0x7271, + 0x7278, +}; + +static void __init mcp_b53_set(void) +{ + unsigned int i; + u32 reg; + + reg = brcmstb_get_family_id(); + + for (i = 0; i < ARRAY_SIZE(b53_mach_compat); i++) { + if (BRCM_ID(reg) == b53_mach_compat[i]) + break; + } + + if (i == ARRAY_SIZE(b53_mach_compat)) + return; + + /* Set all 3 MCP interfaces to 8 credits */ + reg = cbc_readl(CPU_CREDIT_REG); + for (i = 0; i < 3; i++) { + reg &= ~(CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK << + CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i)); + reg &= ~(CPU_CREDIT_REG_MCPx_READ_CRED_MASK << + CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i)); + reg |= 8 << CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i); + reg |= 8 << CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i); + } + cbc_writel(reg, CPU_CREDIT_REG); + + /* Max out the number of in-flight Jwords reads on the MCP interface */ + reg = cbc_readl(CPU_MCP_FLOW_REG); + for (i = 0; i < 3; i++) + reg |= CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK << + CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(i); + cbc_writel(reg, CPU_MCP_FLOW_REG); + + /* Enable writeback throttling, set timeout to 128 cycles, 256 cycles + * threshold + */ + reg = cbc_readl(CPU_WRITEBACK_CTRL_REG); + reg |= CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE; + reg &= ~CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK; + reg &= ~(CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK << + CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT); + reg |= 8; + reg |= 7 << CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT; + cbc_writel(reg, CPU_WRITEBACK_CTRL_REG); +} + +static int __init setup_hifcpubiuctrl_regs(struct device_node *np) +{ + struct device_node *cpu_dn; + int ret = 0; + + cpubiuctrl_base = of_iomap(np, 0); + if (!cpubiuctrl_base) { + pr_err("failed to remap BIU control base\n"); + ret = -ENOMEM; + goto out; + } + + mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing"); + + cpu_dn = of_get_cpu_node(0, NULL); + if (!cpu_dn) { + pr_err("failed to obtain CPU device node\n"); + ret = -ENODEV; + goto out; + } + + if (of_device_is_compatible(cpu_dn, "brcm,brahma-b15")) + cpubiuctrl_regs = b15_cpubiuctrl_regs; + else if (of_device_is_compatible(cpu_dn, "brcm,brahma-b53")) + cpubiuctrl_regs = b53_cpubiuctrl_regs; + else { + pr_err("unsupported CPU\n"); + ret = -EINVAL; + } + of_node_put(cpu_dn); + + if (BRCM_ID(brcmstb_get_family_id()) == 0x7260) + cpubiuctrl_regs = b53_cpubiuctrl_no_wb_regs; +out: + of_node_put(np); + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static u32 cpubiuctrl_reg_save[NUM_CPU_BIUCTRL_REGS]; + +static int brcmstb_cpu_credit_reg_suspend(void) +{ + unsigned int i; + + if (!cpubiuctrl_base) + return 0; + + for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++) + cpubiuctrl_reg_save[i] = cbc_readl(i); + + return 0; +} + +static void brcmstb_cpu_credit_reg_resume(void) +{ + unsigned int i; + + if (!cpubiuctrl_base) + return; + + for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++) + cbc_writel(cpubiuctrl_reg_save[i], i); +} + +static struct syscore_ops brcmstb_cpu_credit_syscore_ops = { + .suspend = brcmstb_cpu_credit_reg_suspend, + .resume = brcmstb_cpu_credit_reg_resume, +}; +#endif + + +static int __init brcmstb_biuctrl_init(void) +{ + struct device_node *np; + int ret; + + /* We might be running on a multi-platform kernel, don't make this a + * fatal error, just bail out early + */ + np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl"); + if (!np) + return 0; + + ret = setup_hifcpubiuctrl_regs(np); + if (ret) + return ret; + + ret = mcp_write_pairing_set(); + if (ret) { + pr_err("MCP: Unable to disable write pairing!\n"); + return ret; + } + + mcp_b53_set(); +#ifdef CONFIG_PM_SLEEP + register_syscore_ops(&brcmstb_cpu_credit_syscore_ops); +#endif + return 0; +} +early_initcall(brcmstb_biuctrl_init); |