diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-23 18:36:55 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-23 18:36:55 -0800 |
commit | f2c73464d7b399cf4e0c601c1c7d7b079080fa52 (patch) | |
tree | 902decd0c280757075bce5068fee679e0ccc261e /drivers/clk/at91/clk-main.c | |
parent | 93abdb7785503c269e73e811f3c7fd23a9243b14 (diff) | |
parent | 273c2279ca502267fac40bcaecb35942380c429c (diff) |
Merge tag 'cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC cleanups from Olof Johansson:
"This is the branch where we usually queue up cleanup efforts, moving
drivers out of the architecture directory, header file restructuring,
etc. Sometimes they tangle with new development so it's hard to keep
it strictly to cleanups.
Some of the things included in this branch are:
* Atmel SAMA5 conversion to common clock
* Reset framework conversion for tegra platforms
- Some of this depends on tegra clock driver reworks that are shared
with Mike Turquette's clk tree.
* Tegra DMA refactoring, which are shared branches with the DMA tree.
* Removal of some header files on exynos to prepare for
multiplatform"
* tag 'cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (169 commits)
ARM: mvebu: move Armada 370/XP specific definitions to armada-370-xp.h
ARM: mvebu: remove prototypes of non-existing functions from common.h
ARM: mvebu: move ARMADA_XP_MAX_CPUS to armada-370-xp.h
serial: sh-sci: Rework baud rate calculation
serial: sh-sci: Compute overrun_bit without using baud rate algo
serial: sh-sci: Remove unused GPIO request code
serial: sh-sci: Move overrun_bit and error_mask fields out of pdata
serial: sh-sci: Support resources passed through platform resources
serial: sh-sci: Don't check IRQ in verify port operation
serial: sh-sci: Set the UPF_FIXED_PORT flag
serial: sh-sci: Remove duplicate interrupt check in verify port op
serial: sh-sci: Simplify baud rate calculation algorithms
serial: sh-sci: Remove baud rate calculation algorithm 5
serial: sh-sci: Sort headers alphabetically
ARM: EXYNOS: Kill exynos_pm_late_initcall()
ARM: EXYNOS: Consolidate selection of PM_GENERIC_DOMAINS for Exynos4
ARM: at91: switch Calao QIL-A9260 board to DT
clk: at91: fix pmc_clk_ids data type attriubte
PM / devfreq: use inclusion <mach/map.h> instead of <plat/map-s5p.h>
ARM: EXYNOS: remove <mach/regs-clock.h> for exynos
...
Diffstat (limited to 'drivers/clk/at91/clk-main.c')
-rw-r--r-- | drivers/clk/at91/clk-main.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c new file mode 100644 index 000000000000..8e9e8cc0412d --- /dev/null +++ b/drivers/clk/at91/clk-main.c @@ -0,0 +1,187 @@ +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/delay.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/io.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/sched.h> +#include <linux/wait.h> + +#include "pmc.h" + +#define SLOW_CLOCK_FREQ 32768 +#define MAINF_DIV 16 +#define MAINFRDY_TIMEOUT (((MAINF_DIV + 1) * USEC_PER_SEC) / \ + SLOW_CLOCK_FREQ) +#define MAINF_LOOP_MIN_WAIT (USEC_PER_SEC / SLOW_CLOCK_FREQ) +#define MAINF_LOOP_MAX_WAIT MAINFRDY_TIMEOUT + +struct clk_main { + struct clk_hw hw; + struct at91_pmc *pmc; + unsigned long rate; + unsigned int irq; + wait_queue_head_t wait; +}; + +#define to_clk_main(hw) container_of(hw, struct clk_main, hw) + +static irqreturn_t clk_main_irq_handler(int irq, void *dev_id) +{ + struct clk_main *clkmain = (struct clk_main *)dev_id; + + wake_up(&clkmain->wait); + disable_irq_nosync(clkmain->irq); + + return IRQ_HANDLED; +} + +static int clk_main_prepare(struct clk_hw *hw) +{ + struct clk_main *clkmain = to_clk_main(hw); + struct at91_pmc *pmc = clkmain->pmc; + unsigned long halt_time, timeout; + u32 tmp; + + while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS)) { + enable_irq(clkmain->irq); + wait_event(clkmain->wait, + pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS); + } + + if (clkmain->rate) + return 0; + + timeout = jiffies + usecs_to_jiffies(MAINFRDY_TIMEOUT); + do { + halt_time = jiffies; + tmp = pmc_read(pmc, AT91_CKGR_MCFR); + if (tmp & AT91_PMC_MAINRDY) + return 0; + usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT); + } while (time_before(halt_time, timeout)); + + return 0; +} + +static int clk_main_is_prepared(struct clk_hw *hw) +{ + struct clk_main *clkmain = to_clk_main(hw); + + return !!(pmc_read(clkmain->pmc, AT91_PMC_SR) & AT91_PMC_MOSCS); +} + +static unsigned long clk_main_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + u32 tmp; + struct clk_main *clkmain = to_clk_main(hw); + struct at91_pmc *pmc = clkmain->pmc; + + if (clkmain->rate) + return clkmain->rate; + + tmp = pmc_read(pmc, AT91_CKGR_MCFR) & AT91_PMC_MAINF; + clkmain->rate = (tmp * parent_rate) / MAINF_DIV; + + return clkmain->rate; +} + +static const struct clk_ops main_ops = { + .prepare = clk_main_prepare, + .is_prepared = clk_main_is_prepared, + .recalc_rate = clk_main_recalc_rate, +}; + +static struct clk * __init +at91_clk_register_main(struct at91_pmc *pmc, + unsigned int irq, + const char *name, + const char *parent_name, + unsigned long rate) +{ + int ret; + struct clk_main *clkmain; + struct clk *clk = NULL; + struct clk_init_data init; + + if (!pmc || !irq || !name) + return ERR_PTR(-EINVAL); + + if (!rate && !parent_name) + return ERR_PTR(-EINVAL); + + clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL); + if (!clkmain) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &main_ops; + init.parent_names = parent_name ? &parent_name : NULL; + init.num_parents = parent_name ? 1 : 0; + init.flags = parent_name ? 0 : CLK_IS_ROOT; + + clkmain->hw.init = &init; + clkmain->rate = rate; + clkmain->pmc = pmc; + clkmain->irq = irq; + init_waitqueue_head(&clkmain->wait); + irq_set_status_flags(clkmain->irq, IRQ_NOAUTOEN); + ret = request_irq(clkmain->irq, clk_main_irq_handler, + IRQF_TRIGGER_HIGH, "clk-main", clkmain); + if (ret) + return ERR_PTR(ret); + + clk = clk_register(NULL, &clkmain->hw); + if (IS_ERR(clk)) { + free_irq(clkmain->irq, clkmain); + kfree(clkmain); + } + + return clk; +} + + + +static void __init +of_at91_clk_main_setup(struct device_node *np, struct at91_pmc *pmc) +{ + struct clk *clk; + unsigned int irq; + const char *parent_name; + const char *name = np->name; + u32 rate = 0; + + parent_name = of_clk_get_parent_name(np, 0); + of_property_read_string(np, "clock-output-names", &name); + of_property_read_u32(np, "clock-frequency", &rate); + irq = irq_of_parse_and_map(np, 0); + if (!irq) + return; + + clk = at91_clk_register_main(pmc, irq, name, parent_name, rate); + if (IS_ERR(clk)) + return; + + of_clk_add_provider(np, of_clk_src_simple_get, clk); +} + +void __init of_at91rm9200_clk_main_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_main_setup(np, pmc); +} |