diff options
Diffstat (limited to 'arch/arc/plat-hsdk/platform.c')
-rw-r--r-- | arch/arc/plat-hsdk/platform.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/arch/arc/plat-hsdk/platform.c b/arch/arc/plat-hsdk/platform.c new file mode 100644 index 000000000000..744e62e58788 --- /dev/null +++ b/arch/arc/plat-hsdk/platform.c @@ -0,0 +1,108 @@ +/* + * ARC HSDK Platform support code + * + * Copyright (C) 2017 Synopsys, Inc. (www.synopsys.com) + * + * 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. + */ + +#include <linux/init.h> +#include <linux/smp.h> +#include <asm/arcregs.h> +#include <asm/io.h> +#include <asm/mach_desc.h> + +#define ARC_CCM_UNUSED_ADDR 0x60000000 + +static void __init hsdk_init_per_cpu(unsigned int cpu) +{ + /* + * By default ICCM is mapped to 0x7z while this area is used for + * kernel virtual mappings, so move it to currently unused area. + */ + if (cpuinfo_arc700[cpu].iccm.sz) + write_aux_reg(ARC_REG_AUX_ICCM, ARC_CCM_UNUSED_ADDR); + + /* + * By default DCCM is mapped to 0x8z while this area is used by kernel, + * so move it to currently unused area. + */ + if (cpuinfo_arc700[cpu].dccm.sz) + write_aux_reg(ARC_REG_AUX_DCCM, ARC_CCM_UNUSED_ADDR); +} + +#define ARC_PERIPHERAL_BASE 0xf0000000 +#define CREG_BASE (ARC_PERIPHERAL_BASE + 0x1000) +#define CREG_PAE (CREG_BASE + 0x180) +#define CREG_PAE_UPDATE (CREG_BASE + 0x194) + +#define CREG_CORE_IF_CLK_DIV (CREG_BASE + 0x4B8) +#define CREG_CORE_IF_CLK_DIV_2 0x1 +#define CGU_BASE ARC_PERIPHERAL_BASE +#define CGU_PLL_STATUS (ARC_PERIPHERAL_BASE + 0x4) +#define CGU_PLL_CTRL (ARC_PERIPHERAL_BASE + 0x0) +#define CGU_PLL_STATUS_LOCK BIT(0) +#define CGU_PLL_STATUS_ERR BIT(1) +#define CGU_PLL_CTRL_1GHZ 0x3A10 +#define HSDK_PLL_LOCK_TIMEOUT 500 + +#define HSDK_PLL_LOCKED() \ + !!(ioread32((void __iomem *) CGU_PLL_STATUS) & CGU_PLL_STATUS_LOCK) + +#define HSDK_PLL_ERR() \ + !!(ioread32((void __iomem *) CGU_PLL_STATUS) & CGU_PLL_STATUS_ERR) + +static void __init hsdk_set_cpu_freq_1ghz(void) +{ + u32 timeout = HSDK_PLL_LOCK_TIMEOUT; + + /* + * As we set cpu clock which exceeds 500MHz, the divider for the interface + * clock must be programmed to div-by-2. + */ + iowrite32(CREG_CORE_IF_CLK_DIV_2, (void __iomem *) CREG_CORE_IF_CLK_DIV); + + /* Set cpu clock to 1GHz */ + iowrite32(CGU_PLL_CTRL_1GHZ, (void __iomem *) CGU_PLL_CTRL); + + while (!HSDK_PLL_LOCKED() && timeout--) + cpu_relax(); + + if (!HSDK_PLL_LOCKED() || HSDK_PLL_ERR()) + pr_err("Failed to setup CPU frequency to 1GHz!"); +} + +static void __init hsdk_init_early(void) +{ + /* + * PAE remapping for DMA clients does not work due to an RTL bug, so + * CREG_PAE register must be programmed to all zeroes, otherwise it + * will cause problems with DMA to/from peripherals even if PAE40 is + * not used. + */ + + /* Default is 1, which means "PAE offset = 4GByte" */ + writel_relaxed(0, (void __iomem *) CREG_PAE); + + /* Really apply settings made above */ + writel(1, (void __iomem *) CREG_PAE_UPDATE); + + /* + * Setup CPU frequency to 1GHz. + * TODO: remove it after smart hsdk pll driver will be introduced. + */ + hsdk_set_cpu_freq_1ghz(); +} + +static const char *hsdk_compat[] __initconst = { + "snps,hsdk", + NULL, +}; + +MACHINE_START(SIMULATION, "hsdk") + .dt_compat = hsdk_compat, + .init_early = hsdk_init_early, + .init_per_cpu = hsdk_init_per_cpu, +MACHINE_END |